I'm really interested to see what Variable gets with his 10.5" Grendel pushing the 85gr Sierra's with a faster powder. 31 grains of faster powder behind an 85gr projectile should send it out at a respectable velocity. It wouldn't surprise me to see 2600fps with that combo. I still think 10.5" is a bit short for an LE blaster, especially for bigger guys, which is why I would lean to 12.5" so you could at least have a mid-length handguard, and still suppress with one of the micro-sized cans.
Yes, Variable...I'm very interested in the results as well.
110 gr VMax in 300 BLK or 85 gr Sierra's in Grendel?
I believe I have H335, X-terminator, and Benchmark at home. I'm supposed to be off this weekend, so if the weather allows and I don't get called in I'll chrono some loads. I have no idea what the max safe loads are with those combos, so I guess I'll use wolf brass and ease up to see what happens. Anyone have any ballpark figures for those powders?
ETA: I've seen 95gr. V-max loads with Benchmark listed at 30 grains, H335 listed at 31 grains, and X-terminator listed at 30.6 grains. It looks like the COAL should be 2.20". I'm thinking the 85gr. Sierra might be able to bump up just a notch higher in charge weight from the V-max loads being as it's 5 grains lighter? Opinions?
Last edited by Variable; 04-26-2012 at 12:14 AM.
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QuickLoad suggests that you should get 2375 to 2450 ft/sec with those powders at 50,000 psi in a 10.5" barrel.
The calculations indicate that getting close to 2600 ft/sec may push pressures to 55-60ksi.
Details in PM.
Looking forward to seeing how close your results are to the predictions!
Last edited by JASmith; 04-26-2012 at 12:48 AM.
Fishing for powders and stuff this morning I uncovered my old test batch of 85 grainers that I shot through my 19.5" gun. My crappy notes said they went 2828fps out of that tube with 31 grains of Benchmark at 36 degree temperature. It was only a five shot string, but that ought to give a small hint. I guess I'll try the Benchmark first since I already have some loaded.LOL
Digging through my notebook I now remember why I dropped and forgot about the 85gr. Sierra load...
That load averaged 2520fps at 36 degrees temperature and I was officially addicted to the Grendel right there. Up until that point I never thought an AR would shoot that good for a five shot group.LOL I abandoned everything else and went to that load for things that needed to die, and used Wolf MPT for (relatively)cheap full auto and plinking. I hate reloading, but I'll take another stab at the 10.5" since it would be good to have a home defense round that might not be too overly penetrative.
Well, the weather sucked all day Saturday, and today was a pile of domestic drama/chores. I just set the chrono out the door before it got too dark and shot the 5 benchmark loaded rounds that I had left over. I shot 5 factory Hornadys first to be sure the chrono was going to read everything ok.
I'll post detailed numbers if anyone wants them, but the numbers suck, so there isn't a lot of use for them in my book.
Temperature: 70 deg. F.
Chrono distance: 15 feet from the suppressor front end cap
10.5" AA upper (chrome Sabre bore)
Factory Hornady 123gr. Amax load
Average Velocity: 2214fps
85gr. Sierra HP handload (31gr. Benchmark, CCI #450, AA/Lapua brass)
Average Velocity: 2395fps
The 85gr. sierra load showed no pressure signs FWIW.
Guess I'll skip Benchmark...
Later when I get a chance I'll try the H335 and see what happens.
FWIW: The one time I shot them, I was getting sub-moa @ 2808fps with 31.8gr of TAC....no pressure signs....18" barrel.