The Athlon reticle is excellent, very similar to the PST EBR-7c I had on the rifle before but with much better glass and turrets. Today it was 6 degrees.
200 yard challenge
- Thread starter scuba52
- Start date
The Athlon reticle is excellent, very similar to the PST EBR-7c I had on the rifle before but with much better glass and turrets. Today it was 6 degrees.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Nice shooting and that rig looks great....
10C more to go and then redo the test and compare. I suspect groups will be tighter.
Jerry
Thanks Jerry, everything on this rifle minus the Athlon and Spuhr mount right down to the ammo is from you. Couldn't pass up a NIB deal on the EE for the scope. But now after having plenty of time behind the Athlon I'll definitely be replacing some other scopes as money allows and you'll be getting the business.
Cheers
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Thanks... and hopefully, we will meet at one of the matches this season.
Come on Spring....
Jerry
Come on Spring....
Jerry
That makes me feel better about my groups lol. I was roughly minus five lying in the snow with my bipod on a plastic rifle case to keep it out of the snow lol. Was very stable as I am sure you were. Groups were close. Doesn’t seem to be much of an accuracy shift for the ten degrees. Seems about all the sk will do at the moment. I will also be shooting sk long range next weekend to compare as Jerry has some at my door this week
I was out shooting yesterday, Ontarios family day was put to good use. I needed to zero my two rigs and find a nice spot to go past 200 yards. Just ran cci standard velocity. I was impressed with my group size at 150 and 200 with it. There were "flyers" but the 8 out of ten shots were close to MOA. I need to do more testing and confirm dope numbers. I will document it better and share the results. Sk match, so biathlon, federal gm match and such. It was 0°c and kept my ammo warm.
Look forward to seeing your groups. I'm quite confident that my groups will tighten up a fair bit. These groups were all shot off a bench with bipod and rear bag so quite stable, but also shot on a 90 second timer per group as i tend to do all my shooting practicing in a PRS style format(minus the use of the bench of course most times). Next weekend I'm going to focus a little more and slow down my shots, like I said no excuses for these results they are what they are, no cherry picking and just the results of that days shoot. I'd have posted them even if they had been 6" groups. At the end of the day we are all only shooting to see if we can better our own results and I love seeing people shoot smaller groups so, gives me something to try for. Cheers
It should be very rewarding for you to improve a fair bit over what you posted. The eight five-shot groups at 200 yards averaged 3.55". While ninety seconds for five shots is not a fast rate, especially for a repeater (one shot every 18 seconds), the SK Rifle Match you were shooting gave very good performance for that ammo. You must have had a lot with an ES under 35 fps to achieve a 3.55 average, assuming everything else was near perfect. The ES for that grade of ammo is often higher. You would be well advised to buy more of that lot of SK RM.
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I do believe I was a contributing factor in the results as well. First time shooting with a new rear bag, switched to a game changer instead of what I was used to in my fortune cookie so my weighting may have been a bit off.
On a side note that was 90 seconds for 10 shots, so 9 seconds per shot aloud. Still by no means a very high rate but for a bolt gun and with many of the drills I run seemed a good time frame.
A very fun drill I was shown is a 90 second 3 position shoot on a 1" target. Start standing mag inserted bolt open, drop to prone position for 2 shots, up to improvised baricade for 4 shots then to another improvised position like chair on top of the bench for the last 4 shots. Ita very easy to shoot well under the time, but it's not a race so it helps you work on time management using almost the whole time allotted to focus on making your shots count and not rushing things.
On a side note that was 90 seconds for 10 shots, so 9 seconds per shot aloud. Still by no means a very high rate but for a bolt gun and with many of the drills I run seemed a good time frame.
A very fun drill I was shown is a 90 second 3 position shoot on a 1" target. Start standing mag inserted bolt open, drop to prone position for 2 shots, up to improvised baricade for 4 shots then to another improvised position like chair on top of the bench for the last 4 shots. Ita very easy to shoot well under the time, but it's not a race so it helps you work on time management using almost the whole time allotted to focus on making your shots count and not rushing things.
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To be honest a lot of the knowledge you have is well beyond me but reading any and all info on any subject always helps so thank you. I just shoot, I have never used a chrony or had any data on any of my ammo.
- Location
- Okanagan Valley B.C.
ya , a long day , just two of shooting more koffee and social time as well.
I dunno, Glenn. I don't think it can be looked at that way. It's one thing to shoot 50 to a single POA over a chronograph, witnessing the ES for an entire box, and another to break it up into 10-shot chunks. Here's a couple graphs I made a few years back, when I compared SK Std, Rifle Match, Lapua Center-X, Midas+ and X-Act. They all had very similar ES values, in the 40-45ish range. But, per 10-shot chunk, they're easily holding less than 35 fps ES. If a major outlier occurs in a 10-shot string, it doesn't look as bad if the other 9 shots average close to the outliers velocity, versus how the 50-shot composite would appear. I wouldn't be rushing out to buy some of that ammo he shot...
I understand what you're saying. It's correct that the chances for a smaller ES improve with a smaller sample size. In other words, any five random rounds could have a smaller ES than the entire sample size of 50 rounds.
But without knowing more about the ammo's standard deviation, it is impossible to say with any certainty what those chances for a smaller ES really are. In the meantime, the laws of chance would say that if a box of ammo has an ES, say of 35 fps, any two rounds taken randomly out of that box would have the same chance of being at either end of the spread as any other two rounds in that box. This holds true for more rounds, but with less and less certainty. In other words, without the chrony data to determine the MV of any group of ammo, we simply cannot know for certain what it is other than to estimate what the overall ES would have to be in order to describe the results achieved down range.
In any case, if I knew of SK Rifle Match with an ES of 35 fps in that regard I would consider it to be very good indeed. Would you agree that if correct the recorded sizes on the eight groups shown above indicate that the groups were very good for SK RM ammo?
But without knowing more about the ammo's standard deviation, it is impossible to say with any certainty what those chances for a smaller ES really are. In the meantime, the laws of chance would say that if a box of ammo has an ES, say of 35 fps, any two rounds taken randomly out of that box would have the same chance of being at either end of the spread as any other two rounds in that box. This holds true for more rounds, but with less and less certainty. In other words, without the chrony data to determine the MV of any group of ammo, we simply cannot know for certain what it is other than to estimate what the overall ES would have to be in order to describe the results achieved down range.
In any case, if I knew of SK Rifle Match with an ES of 35 fps in that regard I would consider it to be very good indeed. Would you agree that if correct the recorded sizes on the eight groups shown above indicate that the groups were very good for SK RM ammo?
I see what you are saying, but i don’t think the odds are lower. It is still an X out of 50 chance per box. Any round could be the surprise and the extreme spread is the extreme spread. You could have a four shot group in an inch the the surprise hits and that one inch is 5 inch.
I don’t think the small sample size changes anything, unless you can predict the ones that will be way out by weighing and measuring for the extremes. I’m going with grunhanen and the es of this ammo is good and that is the deciding factor
I don’t think the small sample size changes anything, unless you can predict the ones that will be way out by weighing and measuring for the extremes. I’m going with grunhanen and the es of this ammo is good and that is the deciding factor
The ES of an ammo is impossible to know without chronographing a reasonable sample size. What should that sample size be? The smaller it is, the more unreliable and less useful the data is. For example, chronying five rounds from a box of .22LR ammo will reveal little useful information. I don't remember the math and will add it if possible, but a sample size of 30 will give a significantly more reliable set of data for evaluating .22LR ammo. In other words, a sample size of 30 is statistically valid, while a size of 5 or 10 is not.
More important to .22LR shooters is the standard deviation (SD) of a particular batch or lot of ammo. Like ES a sample size that is larger rather than smaller is important for statistical reliability. The lower the SD, the better. The best .22LR ammo can have an SD as low as 5 fps. More common, even among expensive match ammos, are SD values of 10 fps and higher. What does that mean?
If a very, very good lot of, say, Tenex, has an SD of 5 fps, that means that 68% of the rounds in a valid sample size will have an MV within plus or minus 5 fps of the average MV. That is if the average MV is 1065, 68% of the ammo will fall between 1060 fps and 1070 fps. Further, the SD math means that 95% of the ammo will be within 2 SD or plus or minus 10 fps of the average MV. In this same example 95% will fall between 1055 fps and 1075 fps. The remaining 5% of the ammo will fall outside of that range but within the overall ES of the ammo.
For a visual explanation of SD, see below. Think of the 68-95-99.7 Rule when considering SD. The example, uses an SD value of 10, but for the purposes of illustration here is with very, very good .22LR ammo with an SD of 5 fps. The example is taken from h t t p s://precisionrifleblog.com/2015/04/18/how-much-does-sd-matter/
To continue, if the best .22LR ammo has an SD as low as 5 fps, what SD can shooters expect out of average "good" ammo? Many "good" ammos will have an SD of 10 fps. To illustrate, consider an ammo with an average MV of 1065 fps. With an SD of 10 fps 68% of the ammo will have an MV plus or minus 10 fps of the average MV, a range of 1055 - 1075 fps. And 95% of the ammo will have an MV between 1045 and 1085 fps. The remaining 5% will be outside that range but within the ammo's ES.
If a shooter knows the SD of the ammo in addition to the ES, he is better off. The higher the SD the greater the percentage of the ammo in the box will be closer to the high and low velocities of the extreme spread. Ammo with a high SD is not reliable for target shooting, especially as distance to target increases. A high SD means that more and more of the ammo is closer to either end of the extreme velocity spread. For example consider an ammo with an ES of 40 fps. Alone this sounds like many ammos that shooters reading these pages might regularly use. It can easily include some of the more expensive ammos as well as more affordable ones. Tenex can have an ES of 40 fps, as can Center X; so too can Eley Club or SK Rifle Match.
Very good Tenex with an SD of 5 fps will have 68% of its ammo falling within plus or minus 5 fps of the average MV, a 10 fps range. A further 27% will be within 10 fps of the average MV. This means 95% of the Tenex with an SD of 5 fps will be within 10 fps (plus or minus) of the average MV. The remainder will be at closer to the extreme high and low MV of the ES.
SK Rifle Match with an SD of 10 will have 68% of its ammo falling within plus or minus 10 fps of the average MV, a 20 fps range. Some 27% of the ammo will be with 20 fps of the average MV, a range of 40 fps. In short 95% of the SK Rifle Match with an SD of 10 fps will be within 20 fps (plus or minus) of the average MV. The remainder will be closer to the extreme high and low of the ES.
Clearly, having more of the rounds being closer to the average MV is very desirable. It gives the shooter greater assurance that most of his rounds will be relatively consistent, closer to the ammo's average MV.
What does all this mean? Knowing the ES of his ammo gives the shooter only a partial understanding of how the ammo will perform. He can know what the velocity spread might look like over the course of using a large sample size of his ammo. Knowing the SD of his ammo will give the shooter a fuller understanding of how he can reliably expect his ammo to perform. In short, the ES doesn't tell an ammo's complete story, doesn't paint a complete picture of its nature. The SD of an ammo adds much-needed colour.
Ammo MV consistency as described in its SD is more and more relevant as distance increases. While it alone doesn't guarantee good results, whether on paper or on steel, it is no less important than ES. It's very important measure of the quality of an ammo. Of course an ammo's price tag doesn't guarantee either a low SD or a low ES, both of which are needed especially as range increases.
This is not to suggest that shooters need to chronograph their ammo to know how it will perform. A shooter can simply shoot and see what happens without ever using a chrony. This is what most shooters do, this one included (I have a chronograph but haven't used it in years). If his results are good, he has good ammo. Further, if the results are good, his rifle and shooting are good. But what explains inconsistent results (overlooking for the time the conditions)? Here the shooter is on less sure footing. Is it the ammo, the rifle, the shooter, or a combination of the three (again, disregarding conditions)? Chronographing can help explain the results obtained down range. It doesn't dictate them. The results should be the same regardless whether a chronograph was used. At the same time it's useful to understand why results can be as they are.
More important to .22LR shooters is the standard deviation (SD) of a particular batch or lot of ammo. Like ES a sample size that is larger rather than smaller is important for statistical reliability. The lower the SD, the better. The best .22LR ammo can have an SD as low as 5 fps. More common, even among expensive match ammos, are SD values of 10 fps and higher. What does that mean?
If a very, very good lot of, say, Tenex, has an SD of 5 fps, that means that 68% of the rounds in a valid sample size will have an MV within plus or minus 5 fps of the average MV. That is if the average MV is 1065, 68% of the ammo will fall between 1060 fps and 1070 fps. Further, the SD math means that 95% of the ammo will be within 2 SD or plus or minus 10 fps of the average MV. In this same example 95% will fall between 1055 fps and 1075 fps. The remaining 5% of the ammo will fall outside of that range but within the overall ES of the ammo.
For a visual explanation of SD, see below. Think of the 68-95-99.7 Rule when considering SD. The example, uses an SD value of 10, but for the purposes of illustration here is with very, very good .22LR ammo with an SD of 5 fps. The example is taken from h t t p s://precisionrifleblog.com/2015/04/18/how-much-does-sd-matter/
To continue, if the best .22LR ammo has an SD as low as 5 fps, what SD can shooters expect out of average "good" ammo? Many "good" ammos will have an SD of 10 fps. To illustrate, consider an ammo with an average MV of 1065 fps. With an SD of 10 fps 68% of the ammo will have an MV plus or minus 10 fps of the average MV, a range of 1055 - 1075 fps. And 95% of the ammo will have an MV between 1045 and 1085 fps. The remaining 5% will be outside that range but within the ammo's ES.
If a shooter knows the SD of the ammo in addition to the ES, he is better off. The higher the SD the greater the percentage of the ammo in the box will be closer to the high and low velocities of the extreme spread. Ammo with a high SD is not reliable for target shooting, especially as distance to target increases. A high SD means that more and more of the ammo is closer to either end of the extreme velocity spread. For example consider an ammo with an ES of 40 fps. Alone this sounds like many ammos that shooters reading these pages might regularly use. It can easily include some of the more expensive ammos as well as more affordable ones. Tenex can have an ES of 40 fps, as can Center X; so too can Eley Club or SK Rifle Match.
Very good Tenex with an SD of 5 fps will have 68% of its ammo falling within plus or minus 5 fps of the average MV, a 10 fps range. A further 27% will be within 10 fps of the average MV. This means 95% of the Tenex with an SD of 5 fps will be within 10 fps (plus or minus) of the average MV. The remainder will be at closer to the extreme high and low MV of the ES.
SK Rifle Match with an SD of 10 will have 68% of its ammo falling within plus or minus 10 fps of the average MV, a 20 fps range. Some 27% of the ammo will be with 20 fps of the average MV, a range of 40 fps. In short 95% of the SK Rifle Match with an SD of 10 fps will be within 20 fps (plus or minus) of the average MV. The remainder will be closer to the extreme high and low of the ES.
Clearly, having more of the rounds being closer to the average MV is very desirable. It gives the shooter greater assurance that most of his rounds will be relatively consistent, closer to the ammo's average MV.
What does all this mean? Knowing the ES of his ammo gives the shooter only a partial understanding of how the ammo will perform. He can know what the velocity spread might look like over the course of using a large sample size of his ammo. Knowing the SD of his ammo will give the shooter a fuller understanding of how he can reliably expect his ammo to perform. In short, the ES doesn't tell an ammo's complete story, doesn't paint a complete picture of its nature. The SD of an ammo adds much-needed colour.
Ammo MV consistency as described in its SD is more and more relevant as distance increases. While it alone doesn't guarantee good results, whether on paper or on steel, it is no less important than ES. It's very important measure of the quality of an ammo. Of course an ammo's price tag doesn't guarantee either a low SD or a low ES, both of which are needed especially as range increases.
This is not to suggest that shooters need to chronograph their ammo to know how it will perform. A shooter can simply shoot and see what happens without ever using a chrony. This is what most shooters do, this one included (I have a chronograph but haven't used it in years). If his results are good, he has good ammo. Further, if the results are good, his rifle and shooting are good. But what explains inconsistent results (overlooking for the time the conditions)? Here the shooter is on less sure footing. Is it the ammo, the rifle, the shooter, or a combination of the three (again, disregarding conditions)? Chronographing can help explain the results obtained down range. It doesn't dictate them. The results should be the same regardless whether a chronograph was used. At the same time it's useful to understand why results can be as they are.
