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Posted: 2/21/2016 9:57:12 PM EDT
Got out today and shot 10 shot strings of H4895 under 75gr Hornady hpbt.  2.255COAL.  This out of a WOA 18" suppressed AR in mid length gas system.  

22.9 gr 2685 FPS AVE 19.6 SD

23.2 gr 2692 FPS AVE 17.5 SD

23.5 gr 2742 FPS  17.1 SD

23.8 gr  2783 FPS  13.2 SD

24.1 gr  2817 FPS  12.4 SD

24.4 gr  2828 FPS  19.3 SD

Now to start working 23.6gr to 24.2 in .2gr increments and see what there is to see.  Clearly fell off the map at 24.4gr.
Link Posted: 2/21/2016 10:13:34 PM EDT
24gr H4895/Varget under that bullet is a common node. How were the groups otherwise?
Link Posted: 2/22/2016 1:19:00 PM EDT
[Last Edit: 2/22/2016 1:20:06 PM EDT by borderpatrol]
Try less powder, 22.5 grains of H4895 shoots well with 75 grain and 77 grain match bullets. I think anything over 23.0 grains is pushing the envelope pressure wise.

Your velocity tells me your too hot. A 20" barrel is close to maximum at 2650 fps. I'd be looking at 2600 fps as a working limit.
Link Posted: 2/22/2016 1:38:54 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By borderpatrol:
Try less powder, 22.5 grains of H4895 shoots well with 75 grain and 77 grain match bullets. I think anything over 23.0 grains is pushing the envelope pressure wise.

Your velocity tells me your too hot. A 20" barrel is close to maximum at 2650 fps. I'd be looking at 2600 fps as a working limit.
View Quote



+1

22.5 grains of H4895 for the H75 is a common Service Rifle Pet Load. Those are typically 1:7 20" bbls and generate a very consistent 2650 fps for WOA and CLE prepped rigs.

How did those primers look on the heavier charges?
Link Posted: 2/22/2016 11:46:08 PM EDT
I shoot a load of 24 grains of H4895 over a 75 AMAX loading .01 off the lands which is into single load only area

It shoots better than me at 600 yds and has no pressure signs and still have good brass life
Link Posted: 2/23/2016 10:14:23 PM EDT
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By borderpatrol:
Try less powder, 22.5 grains of H4895 shoots well with 75 grain and 77 grain match bullets. I think anything over 23.0 grains is pushing the envelope pressure wise.

Your velocity tells me your too hot. A 20" barrel is close to maximum at 2650 fps. I'd be looking at 2600 fps as a working limit.
View Quote


I'm right there with you and RegionRat for 77 Nosler CC's, except with 22.5 of IMR 4895.  It gave me a 93-2X my first time at 600 yards at Perry out of my RRA NM.  Not sure what the velocity is, don't have a chronograph.
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