Broke a bolt

[Macht]

I sheared a lug on my bolt this last weekend. It came from a reputable manufacturer, so I suspect it was something on my end. My round count isn't that high, maybe ~600 rounds. Of those 600-odd rounds, the vast majority have been handloads. That being said, I don't run any loads that I would consider to be particularly hot. Most of my loads are roughly a grain under max, and have been worked up over a chronograph. Is it possible that the few times I've run hot loads (top ends of load development ladders) were enough to weaken it substantially? Another data point: the bolt broke during my second outing with my new Saker 762. I realize that increases back pressure, but I'm running an adjustable gas block and had it set to just lock back with the suppressor on. I guess my question is: how did I goof, and how can I avoid another premature bolt failure?

[bwaites]

Barrel length?

[Macht]

18" with intermediate gas.

[bwaites]

There have been reports of bolt breakage using suppressors, but I know of at least one member who has run one of his Grendels for years with a suppressor, and only with a suppressor so far as I know. He has a very short barrel however.

In theory, suppressors are hard on all parts of a gun, and since the bolt is the part that moves the most, it makes sense that it would break.

I do know that at least one builder of Grendels specifically tells people not to use a suppressor on his rifles.

It is possible that you got one of those bolts that had a minor flaw that got missed on inspection. I would contact the maker, explain what happened, and get their input.

[cst]

I have 2 precision firearms bolts and my wife has one....2 bolts have seen about 2k rounds. One of which has been shot suppressed with about 500 rounds....no damage detectable yet....but knowing bolt breakage history with other grendels I always have a new one with me in the field

[LRRPF52]

Is your receiver face square?

How much space is in the first baffled chamber of the Saker 7.62?

Were you using 8208XBR with 120 or 123gr?

[Macht]

Although I've never checked, it's a PF built upper using his receiver so I'm confident that it's square. I'm not sure how I'd check the size of the blast chamber. I'm running a Trifecta muzzle brake that acts as a sacrificial blast baffle. The chamber that sits in is fairly large. I run a small variety of loads, a few with 8208. I use 8208 with 95 V-Max, 100 TTSX, and was in early load development with it under a 107 SMK. I have run a couple ladders with the 8208 under the 123 A-Max but generally use CFE with that bullet.

[lead chucker]

Iv used a suppressor on my 18" for years now with probably over 800 rounds. Like you I use an adjustable gas block with it just locking the bolt open on last round. I also suppress my 12" grendel with about 200 rounds on it without a problem. I would guess just a flaw in the bolt but you never know.

[Variable]

I've fired thousands of rounds through my 10.5" with a suppressor, and a good bit of it on full auto. The full auto was almost completely with Wolf 120 MPT, and the 10.5" AA uppers were intentionally undergassed a bit (fixed gas) to play nicely while suppressed. I have fired some fairly warm handloads (120 Nosler BT w/ 31.7gr. Win 748), and Hornady 123 Amax as well in semi. No bolt breakages to date. I did break one extractor a while back, but that's been it breakage-wise.

My suppressor is an AAC 762-SD, so it has quite a bit of volume for the 6.5 Grendel. That probably helps a bit.

When I get the 12.5" built, it'll be used with a much smaller can (Templar Ark30 SBR PMS), so I guess I'll see if that changes much. I'll use an adjustable gas system this go around.

Running suppressed definitely puts a bit more stress on the system. One thing I have noticed in some of my 5.56 Colt uppers is earlier deformation of the cam pin. They wear out a bit faster.

[am4966]

I've been doing alot of research on my 1st suppressor. I've seen some bolts break(556) it's hit or miss, they will not catch every bolt that's not up to Spec. But would probably be fine without suppressor use, since it's harder on the system. I'm gonna get a can and I'll carry a spare just incase and send the other back for replacement. They don't say you can't use for suppressors.

[Macht]

Hmm, from the replies it sounds like it may have just been the bolt. I'm also going to recheck my loads to make sure they're not hotter than I think.