12.5" Pistol

[CrisAnderson27]

Why does your upper have fur?

Lol, because I'd used q-tips to clean up some of the lubrication in there before I started...and they shed. When it was done it got a full bath and oiling before reasaembly.

[CrisAnderson27]

Well, apparently that little bit of overhang was the entire problem. Took the gun out today to do some chrono shots (and test the gas system of course), and it locked open on the empty mag at 2 turns out. I added half a turn and left it there. Worked flawlessly from then on. I put a full magazine in, and didn't have a single failure to cycle, either. SUPER happy with how the gun is running now! I put a bipod on it as well so I could dial in the scope (yes, a bipod on a pistol lol...hopefully that's not illegal as I was ONLY USING IT FOR SIGHTING IN THE GUN), and ended up with about 2moa accuracy. I'm figuring the poorish accuracy is a combination of me and the Wolf 100g ammo, rather than any issue with the gun. Velocity was lower than I expected from all the reading I've done, running from 2,380fps to 2,440fps over 10 or so shots. From the few short barrel threads I've seen for Grendels...I was expecting more consistently closer to 2500fps. Again though...I'm sure Wolf ammo isn't exactly premium lol. I need to pick up more Hornady SST and see how it runs that.

Anyway, here's a short video of a handful of shots. Still getting used to the no shouldering thing with this gun.

https://youtu.be/lyeiPn3i5UE

All in all I'm super pleased. Couldn't ask for more to be honest. Now I just need to grow into it .

[VASCAR2]

I chronographed Wolf 100 grain FMJ out of my 16" 6.5 Grendel with a Magneto Speed chronograph average speed was 2507 FPS. The shorter you go down from 16" generally the more loss in FPS compared to going to longer length barrels.

Just for comparison here are some averages of other factory loads out of my 16" barrel.

PPU 110 grain FMJ avg 2510 FPS

PPU 120 grain BTHP avg 2392 FPS

Hornady 123 Grain A-Max avg 2419 FPS

Hornady 123 grain SST avg 2430 FPS

Wolf 100 grain FMJ avg 2507 FPS, Max 2528 FPS, Min 2486 FPS extreme spread 42 FPS.

The Wolf 100 grain FMJ chronograph average out of an 18" Brownell's barrel was 2571 FPS. Your velocity out of a 12.5" barrel seem pretty good seeing how my 16" only produced 2507 FPS.

[CrisAnderson27]

I chronographed Wolf 100 grain FMJ out of my 16" 6.5 Grendel with a Magneto Speed chronograph average speed was 2507 FPS. The shorter you go down from 16" generally the more loss in FPS compared to going to longer length barrels.

Just for comparison here are some averages of other factory loads out of my 16" barrel.

PPU 110 grain FMJ avg 2510 FPS

PPU 120 grain BTHP avg 2392 FPS

Hornady 123 Grain A-Max avg 2419 FPS

Hornady 123 grain SST avg 2430 FPS

Wolf 100 grain FMJ avg 2507 FPS, Max 2528 FPS, Min 2486 FPS extreme spread 42 FPS.

The Wolf 100 grain FMJ chronograph average out of an 18" Brownell's barrel was 2571 FPS. Your velocity out of a 12.5" barrel seem pretty good seeing how my 16" only produced 2507 FPS.

That makes me curious what my 20" gun will do. I'm building a 10.5" 5.56 next week...so when I take it out to sight it in I'll see about bringing a box of 123g SST, and the Wolf 100g to see what they both do out of the short and long gun.

On the speeds for the 12.5"...it does look like it's doing better than it should be, rather than worse. Black Hole Weaponry told me that it likely would. They use a 3r rifling that supposedly improves accuracy and velocity both.

[VASCAR2]

My Shilen 20" 6.5 Grendel averaged 2511 FPS with 123 grain factory SST ammo. The BHW Polyogonal barrels usually show a little higher velocity. I figure your 20" BHW will give about 2525-2550 FPS with 123 grain SST.

[danm]

Nice, I just received my BCM handguard and Superlative Arms adjustable gas block yesterday so probably will assemble today, with a new build thread

[CrisAnderson27]

VASCAR2, the 20" is an AR15 Performance barrel...5R button rifling. I'll see about getting those numbers this week.

Looking forward to seeing your build danm!!

[VASCAR2]

Well there goes my memory again, sorry for the confusion on my end. I don't have any experience with AR15 Performance.

[danm]

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[danm]

I was planning on shooting today, but started coming down with Flu last night... have to wait till the coming weekend. Curious to see how the Supperlative arms adjustable gas block with bleed off performs.

[CrisAnderson27]

I like it! Can't wait to hear how it shoots!!

My 10.5" 5.56 upper will be here tomorrow. Going to toss it on my pistol lower and head to the range as soon as I can. I'll try to get some velocities out of the 20" rifle with both Wolf and Hornady, and reconfirm my pistol with the Wolf...as well as get some Hornady numbers.

[lead chucker]

Glad to hear you got the grendel running right! Happy shooting!

[CrisAnderson27]

Thanks man!! I've had it out a few times since, and it's running clean as can be!

Funny story, I put a 10.5" 5.56 upper on my 12.5" pistol lower (setup with the H2 buffer for the Grendel), and it cycles perfectly lol. Locks the mag open and runs great.

Good stuff .