Testing loads for accuracy

scott_r

scott_r

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When you guys are testing loads what is your procedure you do? How many shots do you take with a specific bullet/powder charge and how many shots are in you group? Do you shoot off your groups in a fast succesion or wait between a min or two between each shot?
Do you let your barrel cool right down between testing different loads?

Cheers!!
 
I load up three test loads with three different powder charges varying by one grain.I fire three shots one after the other,then let the barrel cool before firing the next group.If a load shows promise,I load up another nine rounds with the same load and judge the load based on several groups.Never judge a load based on one or two groups.
 
I usually shoot 5 shot groups when I'm trying to develope a new load, waiting a minute or two between shots. If anything looks promising, I'll shoot a few 3shot groups to check for consistancy. All @ 100 yards off a bench.
 
Would a warm barrel make your groups rise?? I noticed at the range when the barrel on my swift was cold it grouped well and hit 2 inches above the bull. Once the barrel was warmer it still grouped well but my poi rose 3 inches at times. Does shooting a gun with a warm barrel really change the POI that much??

Cheers!!
 
stubblejumper said:
If your point of impact rises that much,you most likely either have a bedding problem,or a barrel with internal stresses.
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Im yet to have the rifle bedded which will be next on my "to do lists" so it could definetly be a bedding problem.
Can you do anything with regards to internal stress?

Cheers!!
 
Ill load up 3 or 5 rounds and shoot them slowly with low barrel heat. If the speed and accuracy are within the area of what I want, Ill load a bunch more up and go kill some stuff :dancingbanana:
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Begin with the starting load and load 5 rounds. Then go up by half a grain, loading 5 of each until you get to the max load. Keep the loads separate. Then go shooting, off a bench, at 100 yards. Use a different target for each load, shooting slowly and deliberately, for group only. Allow time for cooling between strings of 5. No rapid firing whatsoever.
Once you have a group, look at a ballistics table for how high to sight in at 100. IE a 3.5" high sight in for a .308(and a lot of other calibres) will put you on target out to about 300 yards with no hold over.
"...really change the POI that much..." Yep. A hot barrel can increase group size too.
 
3 shot groups only. My old sniper friend freaks when he hears 5 shot groups! Barrel characteristics change too much after 3, tending to give a false indication of what a barrel can do. I trust a sniper.....
 
Hunting rifles I'll stick to 3 shot groups for a given load....

5 Minutes between shots, till I narrow down the more accurate ones, usually the Top 3 Loads.

Then I'll load 9 of each given load and shoot 3- seperate 3 shot groups from each load to give me a better idea of the "average" that given load will produce.
Works for me:cool:
 
sunray said:
Begin with the starting load and load 5 rounds. Then go up by half a grain, loading 5 of each until you get to the max load. Keep the loads separate. Then go shooting, off a bench, at 100 yards. Use a different target for each load, shooting slowly and deliberately, for group only. Allow time for cooling between strings of 5. No rapid firing whatsoever.
Once you have a group, look at a ballistics table for how high to sight in at 100. IE a 3.5" high sight in for a .308(and a lot of other calibres) will put you on target out to about 300 yards with no hold over.
"...really change the POI that much..." Yep. A hot barrel can increase group size too.
Click to expand...

a guy could shoot up his whole stock of components doing this method

I find as much data for the powder/bullet weight combo as I can. I average the max loads and reduce 4%, and work up in one grain increments until close to max, then its half grain increments. I load 3 of each. Using my chrony, I can get a good idea as to what kind of pressure the load is making before I ever get too hot.

I really could care less if my rifle shot .5" groups with the starting load @ 2300 fps. Id rather hunt with 2800 fps and 1" groups

your mileage may vary
 
sunray said:
Begin with the starting load and load 5 rounds. Then go up by half a grain, loading 5 of each until you get to the max load. Keep the loads separate. Then go shooting, off a bench, at 100 yards. Use a different target for each load, shooting slowly and deliberately, for group only. Allow time for cooling between strings of 5. No rapid firing whatsoever.
Once you have a group, look at a ballistics table for how high to sight in at 100. IE a 3.5" high sight in for a .308(and a lot of other calibres) will put you on target out to about 300 yards with no hold over.
"...really change the POI that much..." Yep. A hot barrel can increase group size too.
Click to expand...

Follow this advice if you want to die of old age and/or run out of powder before coming up with a suitable load!:dancingbanana:

Loading like this for a standard .308 with this procedure:

165gr bullet
IMR 4350 45-49gr
5 shots at .5 increments = 50 bullets.

If you are using premium hunting bullets, you've just spent $30-$60 without actually ever really finding a proper, repeatable load.

You need to be able to make sure that your load is consitently good before selecting it to use. SO that means shootign several groups of the same oad, to check. But whoops!! You can't!! You just used your whole box of Nosler Partitions!!:runaway:

Then it is suggested to use a BALLISTICS TABLE, rather than SHOOTING to tell you where your bullet is going to go at 300 yards!! :runaway:

Probably the poorest suggestion I've ever seen for working up a load.
 
todbartell said:
I really could care less if my rifle shot .5" groups with the starting load @ 2300 fps. Id rather hunt with 2800 fps and 1" groups

your mileage may vary
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See with this particular rifle I would rather have .5" groups. Its a 220 Swift and I can easily get the velocity even with a real mild load but its the .5 or less Im after. Id love to know my varmint rifle is capable of killing a gopher at 350 plus yards, of course human error (my part) would be a huge factor as well :D

Cheers!!
 
scott_r said:
See with this particular rifle I would rather have .5" groups. Its a 220 Swift and I can easily get the velocity even with a real mild load but its the .5 or less Im after. Id love to know my varmint rifle is capable of killing a gopher at 350 plus yards, of course human error (my part) would be a huge factor as well :D

Cheers!!
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If your rifle is capable of those groups at minimum charges, I am sure it's capable of it at higehr velocities, with some tinkering...
 
And that pretty much covers load development, but here are a few other things to consider.

Chronographs are cheap enough now that there is no excuse not to use one during load development. A chronograph will tell you when you have reached the maximum load for your rifle, despite what loads are quoted in the loading manual. The data in the manuals is developed for the average rifle, but your rifle is an individual which has it's own internal dimensions. If the maximum load for a particular bullet weight is 2800 FPS, you know you are at the maximum pressure with those components when 2800 FPS registers on your chronograph. Besides - it makes shooting that much more interesting, and helps you get to know your rifle just a little bit better.

When you are assessing your groups, consistency is more important in your hunting ammo than pin point accuracy. If one load gives you consistent 1.5" groups, but another produces .5" groups but produces a flyer every time - I'd pick the load which consistently prints to an inch and a half. If possible, try to shoot a group at 200 and 300 yards to ensure that the accuracy and trajectory are as you expect.

When you shoot groups to check accuracy during your load development, you are probably shooting from a bench, with the rifle supported fore and aft. After you have worked up your load, shoot the rifle from field positions to ensure there are no surprise changes to the point of impact. This phenomenon occurs for some shooters - with some rifles - when they move away from the bench.
 
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Gatehouse said:
Follow this advice if you want to die of old age and/or run out of powder before coming up with a suitable load!:dancingbanana:

Loading like this for a standard .308 with this procedure:

165gr bullet
IMR 4350 45-49gr
5 shots at .5 increments = 50 bullets.

If you are using premium hunting bullets, you've just spent $30-$60 without actually ever really finding a proper, repeatable load.

You need to be able to make sure that your load is consitently good before selecting it to use. SO that means shootign several groups of the same oad, to check. But whoops!! You can't!! You just used your whole box of Nosler Partitions!!:runaway:

Then it is suggested to use a BALLISTICS TABLE, rather than SHOOTING to tell you where your bullet is going to go at 300 yards!! :runaway:

Probably the poorest suggestion I've ever seen for working up a load.
Click to expand...


I myself dont reload to try and save on cost. I reload to get the best accuracy out of that particular rifle. I dont care how much it costs or how much of my reloading supplies I use :rolleyes:. I can always buy more, if you cant you have the wrong hobby.

If you cant afford to develope an accurate load in your particular rifle with reloading, buy factory and shoot your brains out to find what works best with your rifle and go hunting and be done with it. If all you are looking for is minute of moose or deer, there are many premium factory loads out there that will do just fine while hunting if your rifle likes them.

I myself buy quality rifles and optics to see how they will perform with different loads, cost or time does not ever enter the picture, again part of the hobby.

Reloading has never saved me a buck when shooting quality loads, but I know myself they will work when the time comes.
 
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