6.5 x 284 and H4831SC

[waverly]

I took the new 6.5 x 284 / 7.5 twist / 26 inch barrel to the range to do first time 3 round group developments from 48 to 49.5 grains of H4831SC with the ELD X 143 grain bullet and Fed210M. Velocity is pretty low,,,2750 with 49.5 grains of powder. Book says max is 49 grains while another says 51 grains. I am aiming to increase the speed close to the 3000 fps mark. A slow node was found using 48.3 grains, and 2650 fps average. The OAL is 3.120" and .005" from the lands. I dont see any pressure at all. I will do a ladder to find max velocity. 2750 fps ave with 49.5 grains is the highest speed so far on the first trip out there. I hear some guys pushed it to 52 grains or around there.
What velocity are you guys getting with H4831SC and 26 inch barrel?

Rem. 700 8 twist 26" Broughton barrel, Hornady 140 SST. Load 52.5 H4831sc=2880. loaded at ogive 2.485, oal 3.094. .295 neck, loaded dia. 2.92. Checked with Magneto Speed chrono. Drops are spot on to 600. I haven't checked further. My H4831sc is an older lot. Probably 6-7 years old. Been working on the same 8 lb. jug for a good while.

Waverly

 

[ta6ppc]

I have one gun that shoots 51.6 of 4831 just over 2900 it’s a 1:8.5 brux 27” long
I have another one with a 32” 8 twist krieger that shoots 53.6 of 4831 in the 3100 range
H1000 shoots well and builds nice speed as well as retumbo full case makes nice speed.

my 27” barreled gun won’t tolerate much over the 51.6 load, but it shoots excellent at that charge.

I could never get H4350 to shoot worth a damn and didn’t see the speed that folks claimed either.
I know the 4831 is slower but I’d rather have the reliable accuracy that it provides.

don’t get caught up on speed you’ll just cook your barrel faster!

 

[koger]

I will chime in on this. I have a custom Savage actioned rifle I built myself, with a 30" Benchmark, that shoots 52. 5 grs of H4831 at 3100fps on a chrono. I have another Savage rifle with a 26" sporter barrel on it, and it shoots the same load at 2900fps. Another buddy has the same build as the first one, and his isrunning the same load at 3150 fps. We are shooting Moly coated bullets, with little variation in the fps. Both of the guns with the
Benchmarks barrel, seem to shoot fast, and shoot dang accurate, 1/2" groups at 200yds. This is just my findings, on 3 different guns, and we also shoot some old white box Winchester WLR for primers, we could never get the fps with the Fed match primers, and no better accuracy. Again, just my limited findings.

 

[Breakshunter]

If you want velocity go with RL26, I am at 3070fps in my Cooper with a 24" barrel, load is just under max. That is with Berger 140 hybrids. Lapua brass and federal 210m primers. Start around 48-50gr and work up. Mine maxed at 55, not sure what yours will do so start low and go up. Mine is shooting 1/2-3/4" at 200 which works for me as a hunting rifle.

 

[Jr solocam]

Go to load is 52.5 H4831 with 140 VLD. 2875 fps. Started working with Norma MRP. Getting 2970 with great accuracy. 26".

 

[TackDriv3r]

Loaded up 11 rounds with 143 ELDX, each round stepped up in .3 increments from 48.5 to 52.5 grains with virgin brass since I have to fireform it anyway. 52.5 grains shows 2870 fps, no pressure signs or heavy bolt lift. The last 3 rounds, 51.7, 52.1 and 52.5 seems to be POI and on a plane. Check the primers out from left to right ( 48.5 - 52.5 grains ), seems rounded on edges. Should I try # 8 to # 11, 3 round in increments of .3 grains? Or do I still have more room? Of course fireformed brass will give better results, but still have roughly 60 pieces virgin brass to fireform.

 

[ta6ppc]

Looks like you have more room, ive gone as high as 54 grains of H4831 so long as you have a clean bolt lift with no ejector swipe