Reloading With A Suppressor

[CaptnC]

Ok...I'm thinking we are not on the same page.

I started off with the gas block closed enough it would never hold open after the last shot. I know the case is staying in the chamber a long time. The cases are not totally covered with carbon like I'm used to seeing.

That said, I still have slight signs of "chamber" pressure.

I never see the ejector mark (little circle on each case head) nor the primer burn through at the firing pin strike.

Notice on the middle case, row 2...you can see how much metal flowed back around the firing pin.

The loads in these cases are now comfortably below max.

As for subsonic...not sure the Grendel is a good choice. I have a 300 BlackOut that is movie quite with 220gr hand loads.

Most reports on sub and pigs...when the bullet hits the sounder is off and running...sounds great in theory but not in reality.

Thanks for all the posts. I do like the fact the brass is coming out with less carbon and it stays on target better. So the gas block was a big plus.

 

[azarcher10x]

First, close the gas block down. You need to put one round in mag, chamber it, and fire. The bolt should not lock back. Keep opening the block up a little at a time, shooting one round at a time, until the bolt locks back on the empty mag. Then open the gas block a tiny bit more for insurance, and you should be good to go.

 

[cohunt]

The pics you posted in post #29--- are those after the asj gas block? If so, you are over pressire-- I see ejector swipes and pierced primers.

Try something, turn the gas block all the way off and fire a round-- eject with the charge handle-- does the brass look the same? If so, you are over pressure.

Only other thing i can think of is you ate bumping your shoulders too much and creating false pressure signs-- how much ate you bumming the shoulder?

 

[cohunt]

I have 1 more thought-- the 6.5g has 2 different bolt face depths (.125 & .136") did you buy a propperly headspaced bolt with your barrel (type 1 or type 2)? Have you checked your headspace with a field gauge?

 

[Trnelson]

I have 1 more thought-- the 6.5g has 2 different bolt face depths (.125 & .136") did you buy a propperly headspaced bolt with your barrel (type 1 or type 2)? Have you checked your headspace with a field gauge?

Good point!! I made a variation of this mistake myself. I had a bolt head lug develop a crack after about 3,000 rounds. I wasn't sure of which bolt face depth I needed, so I bought one of each and sent back the one I didn't need. Mine wouldn't close into battery with the .125" depth, but fell right into battery with the .136". If a guy has a .125" bolt depth and installed a .136" I imagine you'd see some issues due to excess headspace.

 

[CaptnC]

cohunt,
Yes those are after the gas block was installed. I had the exact same problem with pressure signs on the brass with both the 10.5 barrel and the 16" upper.

I sold the complete 16" upper because it was not accurate with the can installed. Plus I had pressure signs. That upper had a Osprey piston system.

Bought the 10.5" complete upper. I have not shot it without the can but one thing I've noticed the ammo loaded H335 is the only ammo that has shown pressure signs.

I also have ammo loaded with Benchmark 107gr TMK that runs just over 2900fps out of my 24" Grendel. I shot several of these without any pressure signs. I also shot some of the "hunting" ammo I have for my 18" and 20" with 123 SST with Benchmark without pressure signs.

I had 5 rounds left of a last attempt to get the 120 GMX loaded with 8208...it shot easily good enough to hunt with. First barrel I have that shot those bullets decent. Still no pressure signs.

Crazy part the velocity of all ammo shot was all around 2200fps.

Lastly, no I have not checked the bolt but the company I bought the upper from build a lot of 6.5 Grendel's so I feel fairly confident they used the right bolt.

The 120 TAC-X bullets loaded with H335 is shooting very accurately...

.5 MOA at 2200fps

Barrel seems to like the bullet, I plan to load some with a different powder when I get back from the hunt this weekend.

We leave tomorrow!

 

[cohunt]

how much are you bumping the shoulder?

I would not continue to shoot those loads that are piercing the primer-- you stand to etch the bolt face if you continue

what is your H335 load with the barnes bullet?
both Hodgdon and barnes reload data shows 2150-2450 with a 24" barrel (their loads range from 25-28 grains of H335)

check your firing pin face/tip-- make sure that its not rough from piercing the primers as that will add to the primer problem---

what primers are you using? maybe try a thicker cup primer

 

[CaptnC]

27.4gr of H335 2200fps from a 10.5" barrel with the SOS .30 Hunter suppressor