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It was fun. Till it became what it is now.
2025 100 yard .22LR discussion thread
- Thread starter grauhanen
- Start date
What do you think the challenge was originally? What do you think has changed with it? Except for the rule that originally said all shots should be within the target circle and now says they shall be in it, what has changed?
Anyone with a qualifying target can post it, including you. There is no minimum size requirement (except that all ten rounds for each group shall be within the target circle). When a shooter achieves a better result he is welcome to post it too. As the first post in the Challenge notes, "THIS IS A CHALLENGE FOR YOURSELF. THERE IS NOTHING PERSONAL. IT IS NOT A COMPETITION. IT IS UP TO YOU AND ONLY YOU TO DO YOUR BEST AND LEARN FROM IT."
If anyone doesn't like the Challenge or thinks it's unfair, they are free to ignore it. The only request is that no one post anything in the Challenge thread other than qualifying entries. This request was made by in the original Challenge thread hosted by Mel (horseman2) and it continues.
You say this again. How has the Challenge changed to offend you?
Focusing on the temperature factor for now, are you suggesting that individual rounds in, for example, a box are affected uniquely or differently by a general change in temperature? That is to say, while some rounds may still perform well, others experience a decline in performance? To put it another way, unless temp is at a certain point for each lot, all bets are off?
This sounds like the old idea that rifles will prefer ammo that is of a certain average MV (like picking a lot of Eley for the MV printed on it rather than how it actually shoots). Of course this is an old wives tale, an idea without merit. Ammo either shoots or it doesn't -- regardless of MV.
Most shooters would acknowledge that when temperatures change, all rounds experience changes in MV. That is to say, all rounds will be faster when it's warmer and all will be slower when it's cooler. Ammo MV is unrelated to performance. When ammo velocity changes it doesn't require that the performance changes.
Information is always welcome. With regard to .22LR performance and temperature changes, it sounds like you are familiar with evidence beyond anecdotal reports. Can you provide direction to evidence that would support and illustrate how temperature changes make some ammo perform less well (or better)? I don't mind seeing reliable information even if it proves me wrong. I hope asking for this is not too much.
go shoot over your garmin into the dirt and just watch the ES/SD of a 50 round string in different temp/humidity conditions, then try to tell me again that the entire box speeds up the same in relation to enviromental conditions, you won't need a target to quickly come to the conclusion that computer generated science and rimfire ammo do not follow each other out in the real world.
I could fill your garage with actual targets shot with all sorts of field notes denoted on them and can show a relationship over the course of an entire year to back everything up, I stopped sharing that information a long long time ago due to the pissing matches on CGN and RFC, it was all available long long before PRS was a thing, long before long range rimfire was a thing, and the information from almost 2 decades ago is excactly the same thing now as it was then, lot numbers and their corolation to temperature and humidty are the most imported factors in rimfire accuracy............there is no presicions required to shoot prs, extreme long range where you've got unlimitted shots to make a hit again are not precision, that is a game of fluke with the laws of averages thrown in, the fourfathers of rimfire accuracy are mostly dead, they passed their info down to a bunch of people who would rather question it then put it into practice, life is short you need to change the way you post on the internet, I'd rather read your posts that say, this is what I shot today, rather then your questions of what would happen if I shot today
poke holes before it's to late glenn, stirring the pot on the internet is so 1990s, you've lost 30 years you're not going to get back, and I am going to leave it at that........bye bye for now
I could fill your garage with actual targets shot with all sorts of field notes denoted on them and can show a relationship over the course of an entire year to back everything up, I stopped sharing that information a long long time ago due to the pissing matches on CGN and RFC, it was all available long long before PRS was a thing, long before long range rimfire was a thing, and the information from almost 2 decades ago is excactly the same thing now as it was then, lot numbers and their corolation to temperature and humidty are the most imported factors in rimfire accuracy............there is no presicions required to shoot prs, extreme long range where you've got unlimitted shots to make a hit again are not precision, that is a game of fluke with the laws of averages thrown in, the fourfathers of rimfire accuracy are mostly dead, they passed their info down to a bunch of people who would rather question it then put it into practice, life is short you need to change the way you post on the internet, I'd rather read your posts that say, this is what I shot today, rather then your questions of what would happen if I shot today
poke holes before it's to late glenn, stirring the pot on the internet is so 1990s, you've lost 30 years you're not going to get back, and I am going to leave it at that........bye bye for now
sometimes, when you add 2 tenths of a grain of powder to a centerfire work up load, there is very little effect on the muzzle velocity but the ES and SD stabilize and drop significantly, and yet 3 tenths of powder passed that, and the ES/SD number go wild, interestingly enough, this same pheunomiom takes place with powders that are not temperature sensitive and given that a particular load shoots well at 18 degrees where it was developed thus falls apart in the winter months and doesn't shoot worth beans in the summer, proven time and time and time again by many people chasing the same goal with their centerfire rifles, test tube ammo built in a lab only has to pass 1 test to be graded to what color box it is sold in........the velocity printed on that box is, the average of their 4 test barrels, is your barrel faster or slower then their averages? is your barrel faster? slower? that number is as useless as the receipt your got when you bought the ammo, and yet internet folk still think it's a valid prospect for when they seak out ammo.......it means one thing, and one thing only........nothing
Correlation? You mean with actual math? Or just eyeballing targets? I wrote a program to help with tuner setup that takes target and chronograph data and via Spearman's rank correlation math it tells me definitively whether or not I've got positive compensation, negative compensation, and how much, and how confident it is in the answer. Going by the results tells you without a doubt whether or not you need to spin your tuner in some more, spin it out some more, or make it lighter or heavier. It tells you whether or not you're homing in on the optimal amount of positive compensation for that distance or if it is getting worse, and which direction you need to go to improve. You can eyeball targets all you like and come to whatever conclusions you want to, but math doesn't lie. When you have very precisely measured targets and good chronograph data to go with it you can have it tell you what is actually going on and how much you should trust the answer. It tells you how much the muzzle velocity is influencing the elevation on target, and how strongly the elevation correlates with the velocity. When the gun is way out of tune it will show you a very strong correlation between muzzle velocity and elevation, either positive or negative. The more out of tune it is, the larger that positive/negative value will be, and the p-value will be very small, indicating a very high correlation between the two. The closer you get to the ideal tune the smaller and smaller that positive/negative value will get and the p-value will grow larger and larger. That means it starts looking more and more like the elevation on target has nothing to do with the velocity. And that's precisely what a well-tuned gun should look like. It should be compensating for velocity differences by altering the launch angle *just enough* to make as little elevation variance show on target as possible. It works very, very well at making that connection between what you're doing to the gun and how it performs as a result. There's no guessing. There's no gut-feeling. There's nothing anecdotal. You have good measurements for muzzle velocity. You have good target measurements. And you feed all of that info into the math and it spits out what is really going on. Takes the human element completely out of the equation, as you should do when pursuing scientific answers.
As I tried to get across to you in the past, shooting results with any given ammo is very reliant on the distance that you are shooting at. Basic exterior ballistics dictates that if you manage to shoot a literally perfect target at 50 yards that shows absolutely no vertical variance whatsoever, but then followed the paths of those bullets out to 100 yards it would not show the same zero vertical variance. Basic exterior ballistics tells you that this is impossible. If you have all bullets going through the same hole at 50 yards they will necessarily go through different holes at 100 yards. The speed variance in the ammo dictates this. When you find a particular lot of ammo that shoots the best you've ever seen at 50 yards it will not also shoot the best you've ever seen at 100 yards. Smaller and smaller variance on target at 50 yards introduces more and more variance at 100 yards. And it works the other way, too, with finding the stuff that shoots best out of your gun at 100 yards will mean that same stuff will shoot worse at 50 yards. When you are finding ammo that shoots best at a given distance you are finding the stuff that gives you the most positive compensation at that distance. And positive compensation is distance-specific. You literally need a different amount at any distance you shoot.
One ammo cannot and does not shoot the same at all distances. Ballistics doesn't work that way. Getting a 1050 fps shot and a 1085 fps shot to go through the same hole at 50 yards means there will be a vertical difference of 0.43 MOA at 100 yards. The 1050 fps shot required a launch angle of 10.827 MOA to hit centre at 50 yards. The 1085 fps shot required a launch angle of 10.368 MOA to hit centre at 50 yards. Here you can see the ballistic calculator drop tables for each and a graph showing the drop of each. (The MOA drop column is multiplied by 10 here just to coax another decimal place out of the calculator, as it is limited to just one decimal place. So the actual drop in MOA is the value listed divided by 10, just in case you wondered.)
As you can see, both shots' drop values are zero inches at 50 yards, or going through the same hole, in other words. This indicates a rifle tuned well for 50 yards and well-matched ammo to go along with it. It gives the ideal amount of positive compensation to hit with the same elevation at 50 yards, but if you continue following the trajectory out to 100 yards you can see they differ by the amount I mentioned above. That's basic exterior ballistics at work. All guns work like this. Take any rifle you wish, and pair it with any ammo you wish, and even ignore tuners. That rifle/ammo pairing will naturally shoot best at a particular distance. It may or may not be a distance you wish to shoot at, but it will have an ideal distance dictated by how they behave with one another. When you are lot-testing ammunition you are likely testing at one particular distance, and when you find the one lot number that shoots best at that distance all you have done is hunted for the rifle/ammo pairing that offered the most positive compensation at that distance, even if you didn't know it. Finding which ammo shoots the best groups at that distance is precisely what that is. It is finding the most positive compensation you can from a rifle/ammo pairing. You are finding the best results for that particular distance. But that doesn't necessarily mean that the distance is going to be the distance that the rifle/ammo pairing would shoot best at. That's likely still another distance. You've simply chosen a distance and hunted for the best results you could find at that distance. If you then shot a bunch of different distances you'd likely find one that it shot best at. And it will shoot worse at all other distances. That's how guns and projectiles work.
Dave mentioned some CCI not liking one temperature extreme or the other. I went so far as to bring a lunchbox to winter matches to keep ammo and handwarmers in to keep the ammo warm throughout the match, and even had enough handwarmers stuffed between my scope and the chamber area of the barrel to keep it warm. The ammo shot as well as it did in the summer when there was snow on the ground. But if I just let them get as cold as the air was it shotgunned horribly. Temperature affects lube behaviour. It affects primer ignition behaviour. It affects powder burn rate behaviour. That all contributes to differences in velocity variation and exit timing. That's not to say that all ammo will show such extremes in similar temperature extremes. All the various components the ammo is made from will have different characteristics of their own that are affected by temperature by differing amounts. Whatever you were using when you thought you didn't really see any differences may have been less sensitive to temperature than the CCI I had good handwarmer luck with. But that doesn't mean temperature didn't affect it at all. Temperature affects all lube, all primer compound, all powder. Some are more sensitive and some are less sensitive, but there are effects when the temperature changes, none the less. The magnitude of those changes can surely vary. But they're never zero. The air itself affects things. I use a ballistic app on my phone to give me scope setting changes for silhouette matches, and the number of clicks it gives me varies from summer to winter temperatures and humidities, and that's not even counting how the ammo behaviour changes. There is a not insignificant difference in the number of clicks I need in January versus August for the turkeys out there at 77 m and the rams out there at 100 m. The 40 m chickens and 60 m pigs are close enough that usually it gives me the same answer, but as it gets further out there I get differing values just due to the air differences.
Missed ya Shorty. Do your results suggest a distance at which PC is maxed out? (if that is not too naive of a question) It seems intuitive that at some point there will be a limit to the amount and rate of barrel rise and therefore PC. Thanks for the amazing contribution.
Well, if we consider what's going on it definitely stands to reason that at some point you can no longer get things to move the way they need to move in order to provide the most help, yeah. If we work out the amount of PC required for each distance it should become apparent whether or not it is something that will remain feasible as you go further and further out. 50-yard benchrest competitions have shown for decades now that 50 yards is definitely in the feasible range. If we take the 1050/1085 fps example and one of the things gleaned from Geoffrey Kolbe's experimentation we can figure out the amount of PC needed for 50 yards rather easily. He figured there seemed to be a roughly 375 fps range accounting for a difference in muzzle exit timing of 1 millisecond. So for every 1 fps increase in muzzle velocity there should be around 1/375th of a millisecond decrease in muzzle exit delay. So for 1050 and 1085 fps we are looking at a difference of 35 fps, and a launch angle difference of 0.459 MOA. (The fairly inconsistent behaviour of 22 LR ammo makes it hard to say exactly 375, too. His data looked pretty noisy, and that's because of how consistent the ammo actually is, or isn't. This is also why you probably need to retweak after changing lot numbers. Exit timing is fighting muzzle swing, and exit timing will/should change between lot numbers. It might be a minimal tweak, but probably *a* tweak.)
0.459 / 35 = roughly 0.0131143 MOA per 1 fps
roughly 0.013114 * 375 = roughly 4.92 MOA per millisecond of upward swing to get good PC for 50 yards. Geoffrey found roughly 6 MOA/ms for 50 metres.
For 100 yards we need these launch angles:
1050 fps 18.198 MOA
1085 fps 17.304 MOA
0.894 MOA difference
0.894/35 = roughly 0.025543
*375 = roughly 9.58 MOA per millisecond of upward swing to get good PC for 100 yards.
That's quite the difference.
for 200 yards
1050 fps 37.525 MOA
1085 fps 35.785 MOA
1.74 MOA difference
1.74/35 = roughly 0.0497143 MOA per 1 fps
*375 = roughly 18.64 MOA per millisecond
Typical benchrest barrel length and contour with typical tuners can obviously get you to 4.92 MOA/ms of upward swing. Moving to 100 yards is going to require speeding that up quite a bit. And quite a bit again for 200 yards. The limiting factor is going to be what the bare barrel speed actually is, since all we can do with a tuner is slow things down. You have to change the barrel contour, and/or probably length, to speed things up. Slapping a tuner on only slows things down, and you need to get the weight roughly correct to slow it down into roughly the right range. And then the actual tuning adjustment gets it fine-tuned. This is precisely why benchrest barrels tend to be pretty much the same length and contour for a given competition, because you all need to be able to get the barrel moving in the same way.
So, how fast is a bare barrel? That's obviously going to depend on length and contour. And I don't really have an answer for this one, as I've never tried to determine how fast any of my bare barrels is moving. (Well, actually, I do have a general idea of how fast my two-flats barrel is moving, but that's another story, and an unusual one.) If I had to guess, I would say this is probably something you could determine with a chronograph and OnTarget software. You could compare the behaviour of actual shots with the expected outcome of ballistically perfect shots for those speeds and figure out how far off the mark things are, providing things are behaving in a relatively sane way, which may not be a given, hehe. It would kind of depend on whether or not you're seeing shots leave around the same time as the direction reversals take place. If you luck out and you aren't seeing reversals then it should be a straight forward task. If you are seeing reversals then you could probably work around it by adding a really small amount of weight to the muzzle. And you should be able to calculate the muzzle swing speed from that. Then you could figure out whether or not it is a waste of time trying to tune for 100 or 200 yards or if it is something you could do. If I had to guess, given how much weight is in a typical tuner, it might be possible that it is moving more than fast enough when bare to make tuning at usable distances feasible. Testing it would obviously tell us how good of a guess that is, hehe. The further out you go, the faster it needs to be. So there would be some limit. I don't know if you'd run into the ammo's usable distance first or not. Might be interesting to test this in order to try to figure that out, hehe.
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Asking questions seems to generate adverse reactions. So below is another.
Two assertions from above.
Two assertions from above.
Are both compatible? I don't pretend to know.
Shorty's post #26 raises some questions.
It makes sense that .22LR ammo that does well at 50 need not do well at 100. Different lots have different rates of dispersion as distance increases. Not all lots shoot equally.
Does it make sense that an ammo that does well at 100 will shoot worse at 50?
As an example, an ammo produces ten-shot averages of 1 MOA at 100, why must it do worse than 1 MOA at 50? If it must do worse than 1 MOA at 50, it would be necessary for the rounds to converge (come closer together) as they reached the target at 100.
Convergence generally doesn't happen with .22LR. There have been instances observed at testing facilities where results acquired at 50 and 100 meters show better MOA results at the further distance than at the closer one. The thing is that these instances have been rare and unpredictable. They happen by chance.
If anything, ammo that does well at 100 would do even better MOA-wise at 50.
Readers shouldn't accept Shorty's claim that ammo that does well at 100 won't do well at 50. They should also question Shorty's claim that a particular lot of match ammo is good for one distance only.
To summarize, if I may, Shorty says a (particular lot of .22LR match) ammo that's good at 50 can't be good at 100. He also says ammo that shoots well at 100 "will shoot worse at 50 yards". In short, ammo is distance-specific, good for one distance only.
It makes sense that .22LR ammo that does well at 50 need not do well at 100. Different lots have different rates of dispersion as distance increases. Not all lots shoot equally.
Does it make sense that an ammo that does well at 100 will shoot worse at 50?
As an example, an ammo produces ten-shot averages of 1 MOA at 100, why must it do worse than 1 MOA at 50? If it must do worse than 1 MOA at 50, it would be necessary for the rounds to converge (come closer together) as they reached the target at 100.
Convergence generally doesn't happen with .22LR. There have been instances observed at testing facilities where results acquired at 50 and 100 meters show better MOA results at the further distance than at the closer one. The thing is that these instances have been rare and unpredictable. They happen by chance.
If anything, ammo that does well at 100 would do even better MOA-wise at 50.
Readers shouldn't accept Shorty's claim that ammo that does well at 100 won't do well at 50. They should also question Shorty's claim that a particular lot of match ammo is good for one distance only.
Unfortunately, no one can know if the ES/SD of a box of ammo will or will not change in different temp/humidity conditions. Once the box is shot, it's gone. Other boxes may be similar, but no two are exactly alike. It's always difficult to gather reliable data. Without any data and evidence, is there any reason to believe that the performance of ammo will change simply because it's a little warmer or cooler.
Does anyone have any direction to evidence about how temperature (or humidity) change affects ammo accuracy performance? (I know Williwaw has commented on this question elsewhere).
It has to. Treat air as a liquid.
The big thing that changes is your entire box brought to temperature, or is one box in your pocket, one sitting on the bench, and going into a warm or cold mag?
IE Bring 1/2 the box to the range the day before and let it acclimate. Leave the other 1/2 in your pocket until you go to load the mag then leave it on the bench.
You're also assuming that rounds are loaded in boxes in the same order they are made....as if they aren't being fed into a funnel hopper 100's at a time.
The big thing that changes is your entire box brought to temperature, or is one box in your pocket, one sitting on the bench, and going into a warm or cold mag?
IE Bring 1/2 the box to the range the day before and let it acclimate. Leave the other 1/2 in your pocket until you go to load the mag then leave it on the bench.
You're also assuming that rounds are loaded in boxes in the same order they are made....as if they aren't being fed into a funnel hopper 100's at a time.
- Location
- Nova Scotia
I mean humidity is measurements of water vapor.
5 seconds of googling. I found ding ding ding Glenn getting the answers he asking here on a silver platter.
5 seconds of googling. I found ding ding ding Glenn getting the answers he asking here on a silver platter.
Dave is one of my best friends. I shoot with him pretty much every week, and have done so for what must now be approaching a couple decades. He doesn't always believe me when I show him the numbers, mostly because he isn't interested in numbers. He's more interested in holes on paper, even when I show him how the numbers actually do explain what he sees on paper. Even when I give him an experiment to try, and when I show up late that day he's already completed the experiment and is humbly showing me the results that match the prediction of the numbers. The thing is, in most cases he's already experimented enough on his own to know how to go about getting the results he's after without having to know anything about the numbers. He actually sciences pretty hard while trying to act like he's no sciencer.
That's not what I said at all. I said if you find the distance that a given ammo shoots its best at then you will also find it will shoot worse at every other distance. This is 100% true. I didn't say that having results that seem pretty good at 100 means it will be crap at 50. In that vein of thought, I said if you find 100 to be the best distance for a given ammo it will be worse beyond and closer than 100. Which it will be. That's how trajectories work. Being able to understand basic physics, and therefore basic ballistics, will allow one to confirm this. "Different lots have different rates of dispersion as distance increases." To be more precise, you should be treating ammo and rifle as a working pair. A given lot of ammo is going to do one thing in my gun and another thing in your gun, more than likely, since every gun vibrates a little differently. Different lots of ammo shoot differently in the same gun because of how the timing of muzzle exit differs in relation to the rifle's vibrational behaviour. It isn't solely due to differences in the ammo. It is due to how those differences interact with the behaviour of a given gun.
"An ammo produces ten-shot averages of 1 MOA at 100, why must it do worse than 1 MOA at 50?" You're misunderstanding what I said, as that is not what I said. I basically said that every gun/ammo combo will have one distance at which it shoots best. And it will indeed shoot worse at every other distance. I'm fairly certain I've spoken about this before with you in the context of shooting silhouette matches where we have animal targets at 40 m, 60 m, 77 m, and 100 m. When I lot test for silhouette ammo I find the lot that gives the best results at the 77 m target and do not bother testing at the other three distances. This is because no matter which distance I choose, if I select what works best at that one distance it will work worse at the other three. And since the turkey at 77 m is the toughest one to hit I want the least amount of dispersion there. So selecting the ammo that gives me the least amount of dispersion at 77 m from my gun ensures I'll have the best chance of hitting those turkeys at 77 m. This should also give a smaller amount of error at the other animals overall than if I instead selected at 40 m, or indeed 100 m. I should get the best average dispersion by selecting at 77 m. Choosing ammo that instead gives the best dispersion at 40 m means that I'll have the worst dispersion at 100 m. I don't recall, but I may have even shown you this example target from a time I chose ammo at 40 m and what happened with it at 60 m, 77 m, and 100 m. (Hint: it is the same 10 shots.)
Mean radius
40 m: 0.407 MOA
60 m: 0.467 MOA
77 m: 0.493 MOA
100 m: 0.501 MOA
And if you take the experiment further and have a great many lot numbers of ammunition to test, and you thoroughly test each one at all four distances, you will find one that shoots best at each distance. And it should come as no surprise that each one has a best distance of those four, and that the other three will indeed be worse than that best distance. That's basic ballistics theory. It's literally how it works. And the graph I shared earlier with the two bullet trajectories to go along with the ballistic calculator output shows precisely why that happens. In that graph the convergence is at 50 yards. But you can find ammo that converges at different distances. And every single time you find the distance that it converges at, you will also find that it has more dispersion at every other distance. It must. Physics dictates it. Not understanding physics is not a good reason to say you shouldn't trust physics. You can trust physics. The physical universe has confirmed that you can trust physics, over and over and over. In fact, we got physics from the physical universe. That's why we gave it that name. You know when even someone like Bryan Litz gets it wrong it might be a complicated subject. Pretty sure he's the guy you're alluding to with your mention of someone doing convergence tests. And he is indeed wrong on this particular point. Physics dictates it without question. The only way one could try to state otherwise would be without a firm enough understanding of the physics involved, for if one did have a good enough grasp on the physics they would see why convergence must happen. And tracing the trajectory of more than one projectile confirms it. Saying "I still say it doesn't." doesn't cut it. You can't beat physics. And if one doesn't believe that you can't beat physics it just means they don't actually understand physics. Because you literally cannot beat physics.
If only we were allowed to gather a statistically meaningful amount of data at a given temperature instead of being limited by law to only shoot a maximum of one box at one temperature. *sigh* I remember the discussion with you concerning how one box shows different chronograph results than the next box. And it seems you still do not understand how statistics works with regard to this issue. The more data you gather in one setting, the more confident you can be in your answer concerning that setting. One box giving slightly different numbers than the next is not the concern you think it is. It isn't difficult to gather reliable data. The more reliable you want your data to be, the more samples you gather. That's how statistics works. All answers carry only a certain amount of trust, and the larger you make your sample size, the more reliable that answer gets. It's why statistics will give you a number telling you that you can trust the chronograph results gathered from 100 shots more than you can trust the chronograph results you gathered from 50 shots. The more data you gather the more reliable it is. Taking two 50-shot samples and seeing that they're not identical does not mean you cannot gather reliable data. If that's the conclusion you come to from comparing two 50-shot samples then you still need to learn a bit more and become a better sciencer.
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Question for Shorty please.
I monitor the sdX and sdY of my 40 shot composite groups to assure myself that my tune is good. What do you think of that idea?
You have already been very generous with your time but if you have an idle moment I'd love to hear the latest on the two flat barrel.
Also, I have 100K rounds through my 22inch Ace Kukri and have a 26 inch Bartlein BR contour incoming. It will be very interesting to see how differently they respond to tuning and how it scores. I have multiple lots of Lapua and some really good shooting SK that I've tuned and shot for score with the old barrel to compare with the new.
I monitor the sdX and sdY of my 40 shot composite groups to assure myself that my tune is good. What do you think of that idea?
You have already been very generous with your time but if you have an idle moment I'd love to hear the latest on the two flat barrel.
Also, I have 100K rounds through my 22inch Ace Kukri and have a 26 inch Bartlein BR contour incoming. It will be very interesting to see how differently they respond to tuning and how it scores. I have multiple lots of Lapua and some really good shooting SK that I've tuned and shot for score with the old barrel to compare with the new.
Those metrics and 40 shots sound like a decent idea to me. I like using OnTarget so much because it gives numbers like those, and mean radius and SD radius. For my testing I adopted using four 25-shot ARA practice targets and combine them for a 100-shot composite group quite a while ago. Gives you a very good indication of what's going on with enough shots to take it as a decent generalization for whatever it is you're testing.
As for my two-flats barrel, which shot the target seen there, sometime last year I noticed something that I was surprised I had overlooked for so long. One of the dimensions I'd given the gunsmith wasn't followed exactly, and I didn't notice it up until that point. One of the sections was slightly too long. Luckily it was the section between the end of the flats and the muzzle, so I could just have the required amount cut off. haha. After I had that taken care of I ran out of Tenex before I could finish testing how it was after chopping a bit of the tip off. As of yet, I haven't snagged a bunch of good ammo for it, so I actually took it off to play a bit more with the original barrel again. But sooner or later here I'll have to see if I can snag a bunch of good ammo for it again and see if the behaviour is improved. Having slightly too much material out at the end made it slightly slower than it should have been, so I am anticipating that it should be slightly easier to make a suitable tuner for it. I'm looking forward to playing around with it some more again just as soon as I can. Speeding it up a little by shortening it should make it a bit less sensitive to precise tuner weight, and if you recall, I was having to use a very, very light tuner before. It should require slightly more weight now, which should make the weight of the tuner less of a fidgety thing. I'll have to make a new tuner that's a little bit heavier, including figuring out just how much heavier, but it should also be less sensitive to how precise the weight is and be easier to dial in as a result. I was ticked off at myself for not noticing that immediately, especially given that I had to send that rifle back to Alberta so many times to get other oversights on their part corrected. Could've had them fix that at the same time, heh.
A 26-inch Bartlein, eh? I'll be interested to hear how you get on with that.
What's the diameter?This response immediately followed the question in the previous post.
Jahnj0584, the question asked about how temperature (or humidity) change affects ammo accuracy performance, not whether it affects MV.
There is little doubt that temperature changes cause MV to change. Muzzle velocity increase as temps rise and go down as temps fall.
With humidity changes, air density changes. The higher the humidity, the less dense the air is. This means a faster bullet. Lower humidity causes denser air and a slower bullet. Generally speaking the effect of temperature is more dramatic than humidity.
The question remains -- how, if at all, does temperature (or humidity) change affect the ammo's accuracy performance? Does ammo accuracy change if it gets warmer or cooler?
While Williwaw hasn't commented in this thread on the question of temperature change and accuracy performance, a few months ago over on RFC he said that temps don't affect his results either.
See post #8 here https://www.rimfirecentral.com/thre...?post_id=13527359&nested_view=1&sortby=oldest
However inconclusive his experience may be I agree with Williwaw. In my experience -- which is not conclusive either -- ammo accuracy performance remains very similar as temps get warmer or cooler.
As a result, the question that was posed at the beginning of the thread remains.
Ammo that does well at 100 one day does less well on another. Is it the shooter or the ammo?
Ammo that does well at 100 one day does less well on another. Is it the shooter or the ammo? (Recall that it was Barthammer's experience with his Challenge post that led to the question.)
To summarize, two answers have been offered to the question that was posed at the beginning of the thread.
First, yodave says that ammo performance depends on temperature (and humidity). In other words, ammo that shoots well when it's 20 degrees Celsius can't do well when it's 10 or 5 degrees. For good results, he says it's necessary to be "matching a lot number to temperature and humidiy" (see post #4).
In yodave's explanation, when temps or humidity changes, ammo performance changes. In other words, a lot that shoots well when it's warm won't do so when it's not (and vice versa). In this view, if a shooter tests a lot and finds it's very good, he should continue looking for ammo as all bets are off when the temps (or humidity) change.
In short, it's not the shooter or the ammo it's the temperature or the humidity. Unfortunately, it's not known at this time if temps (or humidity) were very different when Barthammer had his good and not-as-good experience.
Second, Shorty says it's necessary to match ammo to distance, that when match ammo lots shoot well they do so only at a certain distance. He claims "finding the stuff that shoots best out of your gun at 100 yards will mean that same stuff will shoot worse at 50 yards". (post #26) Of course this requires that the ammo that shoots worse at 50 yards will get better with distance.
It sounds like Barthammer was using the same lot of ammo when he had good results one day and something else on another, but it wasn't confirmed. If it was the same lot, Shorty's explanation for the differences Barthammer experienced remains incomplete.
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Two questions were asked at the beginning: "If all else is the same, is it the shooter or is it the ammo? Wind aside, while we may have .22LR ammo that regularly does well at 50 yards, do we have ammo that's consistent enough to regularly do well at 100?"
It was not imagined when this discussion thread was created that there would be acrimony, especially to questions. While there may be better answers than seen thus far, it seems likely that this discussion is best concluded at point.
If anyone is interested in discussing anything related to 100 yard .22LR shooting they are encouraged to do so. My own interest is gone.
To summarize, two answers have been offered to the question that was posed at the beginning of the thread.
First, yodave says that ammo performance depends on temperature (and humidity). In other words, ammo that shoots well when it's 20 degrees Celsius can't do well when it's 10 or 5 degrees. For good results, he says it's necessary to be "matching a lot number to temperature and humidiy" (see post #4).
In yodave's explanation, when temps or humidity changes, ammo performance changes. In other words, a lot that shoots well when it's warm won't do so when it's not (and vice versa). In this view, if a shooter tests a lot and finds it's very good, he should continue looking for ammo as all bets are off when the temps (or humidity) change.
In short, it's not the shooter or the ammo it's the temperature or the humidity. Unfortunately, it's not known at this time if temps (or humidity) were very different when Barthammer had his good and not-as-good experience.
Second, Shorty says it's necessary to match ammo to distance, that when match ammo lots shoot well they do so only at a certain distance. He claims "finding the stuff that shoots best out of your gun at 100 yards will mean that same stuff will shoot worse at 50 yards". (post #26) Of course this requires that the ammo that shoots worse at 50 yards will get better with distance.
It sounds like Barthammer was using the same lot of ammo when he had good results one day and something else on another, but it wasn't confirmed. If it was the same lot, Shorty's explanation for the differences Barthammer experienced remains incomplete.
_____________________________________
Two questions were asked at the beginning: "If all else is the same, is it the shooter or is it the ammo? Wind aside, while we may have .22LR ammo that regularly does well at 50 yards, do we have ammo that's consistent enough to regularly do well at 100?"
It was not imagined when this discussion thread was created that there would be acrimony, especially to questions. While there may be better answers than seen thus far, it seems likely that this discussion is best concluded at point.
If anyone is interested in discussing anything related to 100 yard .22LR shooting they are encouraged to do so. My own interest is gone.
