Why is my Grendel ar destroying brass

Looks like the bolt is not going back far enough to catch the base. It has enough friction from the spring to strip off the next round by digging into the brass. Then it jams the round partway into the chamber.

Definitely locking lug marks from the bolt.

-R
 
Last edited:
Yup the BCG not going back all the way. My long range Ar was doing the same thing. I fixed mine by moving to a lighter buffer and different spring( the original one was a 1" longer than all my other springs... Lol)
 
Yup the BCG not going back all the way. My long range Ar was doing the same thing. I fixed mine by moving to a lighter buffer and different spring( the original one was a 1" longer than all my other springs... Lol)

Not sure what I've got in it now. It's whatever came with the milspec buffer tube, so given that, what should I try? Pretty sure my buffer is a carbine buffer
 
Last edited:
Not sure what I've got in it now. It's whatever came with the milspec buffer tube, so given that, what should I try? Pretty sure my buffer is a carbine buffer


Hmmm interesting. On mine I had a heavy buffer and it was causing my issues. Went to a standard size and it fixed it. Paging @JBoyette !!! Lol
 
I'd make sure:
1. The spring and buffer are good to go (spring good quality like chrome JP or sprinco) and if they are;
2. It's getting enough gas. (gas port/block alignment, clear tube)

My best non-expert guess.

edit: it would be good to know where the ejected rounds are moving to. Barrel at 12:00, stock at 6:00, the brass should be landing in a pile at about 3:30-4:30 about 6-8 feet out.
 
Last edited:
I'd make sure:
1. The spring and buffer are good to go (spring good quality like chrome JP or sprinco) and if they are;
2. It's getting enough gas. (gas port/block alignment, clear tube)

My best non-expert guess.

edit: it would be good to know where the ejected rounds are moving to. Barrel at 12:00, stock at 6:00, the brass should be landing in a pile at about 3:30-4:30 about 6-8 feet out.

The brass are 3:00-4:00, but not that far out. I was shooting it laying down, and noticed 3-4 feet out, some were 2feet, some were 4-5ft out.

I've shot maybe 300 rounds of wolf, no issues. And about 200 rounds of brass, and it's happened twice now on brass.

I may just need to upgrade my buffer and spring. I bought it all as a kit, with a stock from a member here, that has an online store for $28. So I'm sure it's not of the higher quality parts. My Magpul stock will come off if you adjust it back and tug on it lol.
 
Last edited:
The brass are 3:00-4:00, but not that far out. I was shooting it laying down, and noticed 3-4 feet out, some were 2feet, some were 4-5ft out.
I've shot maybe 300 rounds of wolf, no issues. And about 200 rounds of brass, and it's happened twice now on brass.
I may just need to upgrade my buffer and spring. I bought it all as a kit, with a stock from a member here, that has an online store for $28. So I'm sure it's not of the higher quality parts. My Magpul stock will come off if you adjust it back and tug on it lol.

Hmm. Just a thought, maybe not related, but something to consider. Verify closely that your chamber is clean. If you are shooting steel case Wolf, you will experience a much dirtier chamber. I have had effects that made me start looking at my magazine, but it was a very dirty chamber. The cases would be tight coming out and maybe slowed down the bcg enough to short stroke a little?

Don't know anything about grendel, but i would think it is a pretty tight chamber? I have one 5.56 that shoots steel wolf great. But I had a wylde chambered one that didn't seem to like it and after a hundred rounds or so it would get super sticky. It would be bad when i stuck brass ammo in it. As, the steel didn't seem to fireform, but the brass would, on top of the dirt and crap from the tula.

Just throwing it out there. Maybe worth checking.
 
Wolf is often hotter. Not sure if that holds for Grendel, but if so that would point to undergassed/too much buffer/sticky chamber slowing down the brass cycling too much.
 
Back
Top Bottom