Gun Hub Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter · #1 ·
FYI- I have been using IMR4320 for several years and have been told and have learned from experience that this powder IS NOT consistent lot to lot.
All components are the same for each test and IMR 4320 from 3 different lots.
.223 Rem
S & B case trimmed to 1.750
WSR primer
Win 55 gr FMJBT
1st test-2947 fps- 22.09 SD (standard deviation)
2nd test- 2876 fps- 25.57 SD
3rd test- 3292 fps- 11.00 SD

All test was with same charge of IMR 4320
 

·
Registered
Joined
·
3,449 Posts
All powders invariably have some. You'll tend to find that (if you shoot seriously) you'll be best to buy powder by the 8# jugs.
That'll uniform your SDs, provided all else are equals - i.e. uniformly sized brass, common headstamp & weight . . . perhaps neck tension . . . oh and primers for those long range shots . . very important ! Forget buying pris by the 100, go w/ 1K primers if it suits your shoot. :wink:

The #3 Wow !
 

·
Registered
Joined
·
763 Posts
Rocket2Mars,

I'll bet your chrony's sensors were in direct sunlight for your 3rd test.

Don
 

·
Registered
Joined
·
1,186 Posts
You will need to work on your ammo preparation as that much SD will give you lots of elevation problems at long range. You may not see it up to 300 but 600 it will most likely start to show and by 1000 you will most likely be six ring to six ring for elevation.

You want to get you SD below 10 for long range work.
 
1 - 5 of 5 Posts
Top