How do you test your loads?
- Thread starter Crashediv
- Start date
- Location
- Somewhere on the Hudson Bay Coast
I first determine the maximum working load through 1 gr increments starting at least 5 grs below the anticipated maximum load. I fire each round over a chronograph and watch for a number of pressure signs. As a rule, when the book velocity has been reached, you are at the maximum pressure, which is a rule of thumb that will keep you safe provided you have a number of sources that agree with the components you have chosen.
But first lets discuss pressure signs. As a rule watching primer and brass for pressure signs tends to be unrealiable as some brass is harder than others, and there are variations in primer pocket and, flash-hole sizes, and in primer cup hardness. All the same, if you see an extractor mark which appears as a shiny spot on the case head, you should consider that as a high pressure warning. If you measure the web of the case and discover .001" of expansion, that should be considered a warning sign of high pressure. If you experience a sticky or difficult bolt lift, that is an outright danger sign. If you have a chronograph, any reading higher than book velocity should be taken as a warning, but not all chronographs a re equal, and velocities can also be affected by temperature and barometric pressure. If you have a few factory rounds, it doesn't hurt to use them as a control for your chronograph.
Once I have determined the maximum load, that is the load that shows the earliest signs of pressure, I drop one full grain and determine that to be my maximum working load with those components. Be aware that there can be significant variation in case capacity amongst manufacturers so what is a maximum load in one case might be a bit light or a high pressure in another.
If I intend to tweak this load for accuracy, everything I do from this point on reduces pressure. One difference here is that of the seating depth of my bullet. In a hunting or field load, I want the ammo to feed reliably from the magazine, so I tend to choose bullets with a crimping groove or a cannelure and crimp each round, as crimping tends to uniform the bullet pull weight in a similar fashion to seating the bullet into the lands. When I'm attempting to gain the maximum accuracy, OAL is less important so I begin with the bullet seated out enough to firmly contact the lands. Once I have determined the optimum powder charge, I then experiment with small jumps to the lands which normally reduces pressure in bottle neck cases, but can increase pressure in straight wall cartridges due to the reduced powder capacity.
When I tweak the load for accuracy, I work away from the maximum load in one grain increments. If accuracy improves after the first reduction of one grain, I drop another. If accuracy drops off I go back up a half grain , then by a quarter grain. I don't attempt to adjust finer than a quarter grain because I don't believe that loading scales are accurate enough to uniformly measure differences smaller than a quarter grain.
But first lets discuss pressure signs. As a rule watching primer and brass for pressure signs tends to be unrealiable as some brass is harder than others, and there are variations in primer pocket and, flash-hole sizes, and in primer cup hardness. All the same, if you see an extractor mark which appears as a shiny spot on the case head, you should consider that as a high pressure warning. If you measure the web of the case and discover .001" of expansion, that should be considered a warning sign of high pressure. If you experience a sticky or difficult bolt lift, that is an outright danger sign. If you have a chronograph, any reading higher than book velocity should be taken as a warning, but not all chronographs a re equal, and velocities can also be affected by temperature and barometric pressure. If you have a few factory rounds, it doesn't hurt to use them as a control for your chronograph.
Once I have determined the maximum load, that is the load that shows the earliest signs of pressure, I drop one full grain and determine that to be my maximum working load with those components. Be aware that there can be significant variation in case capacity amongst manufacturers so what is a maximum load in one case might be a bit light or a high pressure in another.
If I intend to tweak this load for accuracy, everything I do from this point on reduces pressure. One difference here is that of the seating depth of my bullet. In a hunting or field load, I want the ammo to feed reliably from the magazine, so I tend to choose bullets with a crimping groove or a cannelure and crimp each round, as crimping tends to uniform the bullet pull weight in a similar fashion to seating the bullet into the lands. When I'm attempting to gain the maximum accuracy, OAL is less important so I begin with the bullet seated out enough to firmly contact the lands. Once I have determined the optimum powder charge, I then experiment with small jumps to the lands which normally reduces pressure in bottle neck cases, but can increase pressure in straight wall cartridges due to the reduced powder capacity.
When I tweak the load for accuracy, I work away from the maximum load in one grain increments. If accuracy improves after the first reduction of one grain, I drop another. If accuracy drops off I go back up a half grain , then by a quarter grain. I don't attempt to adjust finer than a quarter grain because I don't believe that loading scales are accurate enough to uniformly measure differences smaller than a quarter grain.
- Location
- Midland, ON
Hmm, good info so far, a chrony, bench vise type thing to shoot from (like a lead sled thing) and reading as many books as you can get your hands on.
Now for my first response I wanted to put down...
Insert loaded cartridge into the chamber of the firearm loaded for. Aim at target, pull trigger. If it goes BANG and hits the target it is a good load. No bang or hitting target = bad load.
Now for my first response I wanted to put down...
Insert loaded cartridge into the chamber of the firearm loaded for. Aim at target, pull trigger. If it goes BANG and hits the target it is a good load. No bang or hitting target = bad load.
- Location
- Prince Albert, Sk
A complete focus on consistency and routine.
The actual load development is pretty much the same for everything but it is how well and accurately you repeat every step.Brass prep , measuring loads, seating, etc..........the more you repeat these steps without variation the easier and more accurate your testing will be.
Ladder testing gets you to a sweet spot faster than conventional testing.You can visit Mystic Precision for vast amounts of info on reloading and loading for accuracy.
I found that stretching out the distance as far as you can for testing also helps out when fine tuning.
The actual load development is pretty much the same for everything but it is how well and accurately you repeat every step.Brass prep , measuring loads, seating, etc..........the more you repeat these steps without variation the easier and more accurate your testing will be.
Ladder testing gets you to a sweet spot faster than conventional testing.You can visit Mystic Precision for vast amounts of info on reloading and loading for accuracy.
I found that stretching out the distance as far as you can for testing also helps out when fine tuning.
So this is what I do (which is a lot like what Boomer does). Nots sure if this is what "ladder testing" is but I am assumong you are looking to find the best load.
I load 3 of each starting 4 or 5 grains below max load, so usually 18-21 loads
Fire each 3 shot string very slowly, allowing barrel to cool 2 min or so in between shots
Obviously shooting from a bench (I dont have a lead sled) and I use 100 yds
I chrony them as well looking for consistency but I am not worried about velocity I prefer accuracy over a 100 fps for example. The 40 grain loads were about 2550 fps +/- 20
So looking at the picture below, I loaded up my .308 with IMR 3031, Hornady BTSP 150gr bullets. I liked the group at 40 grains which is actually a very mild load. So that's what I am going to use come deer season and I have loaded a bunch of them for practice. The 42 1/2 was pretty good as was 39 & 43. The 41 & 42 were all over the place.
I load 3 of each starting 4 or 5 grains below max load, so usually 18-21 loads
Fire each 3 shot string very slowly, allowing barrel to cool 2 min or so in between shots
Obviously shooting from a bench (I dont have a lead sled) and I use 100 yds
I chrony them as well looking for consistency but I am not worried about velocity I prefer accuracy over a 100 fps for example. The 40 grain loads were about 2550 fps +/- 20
So looking at the picture below, I loaded up my .308 with IMR 3031, Hornady BTSP 150gr bullets. I liked the group at 40 grains which is actually a very mild load. So that's what I am going to use come deer season and I have loaded a bunch of them for practice. The 42 1/2 was pretty good as was 39 & 43. The 41 & 42 were all over the place.
Pretty much the same as Boomer mentioned. I take max load for the bullet weight from reload manual and reduce by 6-8%. Then load 5 rounds each in .2 gr increments until I see pressure signs on cases/primers.
For ex. .223 Rem. 69gr./Varget Load 5 @ 24.4, 5@ 24.6, 5 2 24.8, etc.
Use a perm. marker to label the cartridge container and the bullet in order to keep up with what powder load is what(especially if you spill the loaded rounds)
I video the target @ 400 yds, shoot round robin 1 of 24.4, 1 of 24.6, 1 of 24.8 etc. untill I have gone thru all the rounds. I review the video and and mark a holes in the target with that load # as I see each videoed round hit the target.
You will see one or two groups cluster, say for example #3(24.8) and
#5(25.2). Then do the same process with maybe three rounds from 24.8 to 25.2 in .1 gr increments untill you get to the sweet spot, then play with the seating depth to finalize the best of the best.
Jerry Teo, MysticPlayer on here, CGN, has some info on his website.
I see some have beaten me to it while I typed. Kelly and BB give good info.
For ex. .223 Rem. 69gr./Varget Load 5 @ 24.4, 5@ 24.6, 5 2 24.8, etc.
Use a perm. marker to label the cartridge container and the bullet in order to keep up with what powder load is what(especially if you spill the loaded rounds)
I video the target @ 400 yds, shoot round robin 1 of 24.4, 1 of 24.6, 1 of 24.8 etc. untill I have gone thru all the rounds. I review the video and and mark a holes in the target with that load # as I see each videoed round hit the target.
You will see one or two groups cluster, say for example #3(24.8) and
#5(25.2). Then do the same process with maybe three rounds from 24.8 to 25.2 in .1 gr increments untill you get to the sweet spot, then play with the seating depth to finalize the best of the best.
Jerry Teo, MysticPlayer on here, CGN, has some info on his website.
I see some have beaten me to it while I typed. Kelly and BB give good info.
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make a chart, pick a set of cases, and then try every suitable powder you have available and every suitable primer and every suitable bullet,
start by picking out the best bullet(s) for your gun, narrow down the weight and style based on barrel twist and application (hunting, targets)
now try every combination of powder and primer with each bullet. record all your results
once youve done that, you can look at what has an effect, you may find that a certain powder charge works great with every primer you tried and the bullets you prefer to use, you might find only brand A primers give you good results. now repeat for all your guns
start by picking out the best bullet(s) for your gun, narrow down the weight and style based on barrel twist and application (hunting, targets)
now try every combination of powder and primer with each bullet. record all your results
once youve done that, you can look at what has an effect, you may find that a certain powder charge works great with every primer you tried and the bullets you prefer to use, you might find only brand A primers give you good results. now repeat for all your guns
I work my load up in 1 grain incriments and record the data, velocity and the group. I then find a "best range" and start at the lowest and work up new loads using half grain increments. I keep on narrowing it down until I have the best load. It takes a while but shooting is so much fun it is really a win win. I use the program Point Blank, to keep a data base of all my reloading work.
Some bullets and some powders are well known to produce good results in certain calibers. Useing H4831 in a .270, Varget or 4895 in a .308, RL22 or H1000 in a .300 Win are a fast track for quick success. So is starting with a decent barrel. Its easy to spend the equivilant of a match barrel trying to make a crowbar into a tack driver.
I start at the lands, and work up 1 grain at a time until the maximum is reached or pressure signs are visible. For convenience, this is usually done at 100 yards. Something usually starts looking fairly good in the pressure series or I may just scrap that combo. I pay as much attention to the poi of the groups as the pure size of the groups at first unless it is all total crap.
Say the lightest load was dead on, and the 1 grain up hit a little higher and the next still higher. Usually there will be a point in the series where the groups would stack if they were shot on the same target, and with a bit of good fortune it will be at the upper end of the data. You can call it a sweet spot, or a node or even a power-band if you like engines, but the end result is that within a certain range you could have taken 1 cartridge of each charge and shot a decent group. Loads like that don't tend to go sour or change their POI of everytime the temperature drops or the sun goes behind a cloud.
Working within that range I'll load up from 10 to 20 of each and usually move way out. I've found that pondering chronograph results and trying to deduce whether something is a 500 yard deer load is a poor substitute for just shooting it at that distance. Ditto for thinking that 100 yard results mean much of anything at 500 or 1000. The vertical component of the group is the thing to watch.
After determineing that I have a load, I might play around with COL, or maybe not.
Some cartridges and applications are different. For the first try with H4895 in my .458 Win I just loaded 1 shell each from bottom to top, fired them over the chronograph and checked to see if anything fell off me or the gun. Then I loaded 6 each of the top 2 charges and shot them to see if they were "good enough". They were, ironically shooting some cloverleafs with a rifle that really only needs to be minute of elephant.
I start at the lands, and work up 1 grain at a time until the maximum is reached or pressure signs are visible. For convenience, this is usually done at 100 yards. Something usually starts looking fairly good in the pressure series or I may just scrap that combo. I pay as much attention to the poi of the groups as the pure size of the groups at first unless it is all total crap.
Say the lightest load was dead on, and the 1 grain up hit a little higher and the next still higher. Usually there will be a point in the series where the groups would stack if they were shot on the same target, and with a bit of good fortune it will be at the upper end of the data. You can call it a sweet spot, or a node or even a power-band if you like engines, but the end result is that within a certain range you could have taken 1 cartridge of each charge and shot a decent group. Loads like that don't tend to go sour or change their POI of everytime the temperature drops or the sun goes behind a cloud.
Working within that range I'll load up from 10 to 20 of each and usually move way out. I've found that pondering chronograph results and trying to deduce whether something is a 500 yard deer load is a poor substitute for just shooting it at that distance. Ditto for thinking that 100 yard results mean much of anything at 500 or 1000. The vertical component of the group is the thing to watch.
After determineing that I have a load, I might play around with COL, or maybe not.
Some cartridges and applications are different. For the first try with H4895 in my .458 Win I just loaded 1 shell each from bottom to top, fired them over the chronograph and checked to see if anything fell off me or the gun. Then I loaded 6 each of the top 2 charges and shot them to see if they were "good enough". They were, ironically shooting some cloverleafs with a rifle that really only needs to be minute of elephant.
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Good advice here guys.........
That's the fun thing about this, we can load up millions of different loads trying to find the best one, and getting to go shooting is half the fun. Cases, primers, powders, bullet seating, it all plays a factor.
I found (as per Dogleg) that Varget does shoot very well in my .308, but I have 3 lbs of 3031 to use up....pretty much anything shoots well in my .270 (Win 785 shot the best and OH HOW I WISH it was still available)
That's the fun thing about this, we can load up millions of different loads trying to find the best one, and getting to go shooting is half the fun. Cases, primers, powders, bullet seating, it all plays a factor.
I found (as per Dogleg) that Varget does shoot very well in my .308, but I have 3 lbs of 3031 to use up....pretty much anything shoots well in my .270 (Win 785 shot the best and OH HOW I WISH it was still available)
