Broken Bolt?

[sawgunner2001]

I have a PWS Mk 110 upper (.223 Wylde, non-adjustable gas) from circa 2011 or 2012 - sheared off a bolt lug yesterday.

I purchased the upper new and have been running a SiCo Specwar 762 suppressor on it. 99% of rounds fired have been suppressed. I ended up running an XH carbine buffer from HeavyBuffers.com (8.5oz) and a Wolff XP carbine buffer spring to reduce the amount of gas blowback.

Yesterday, at a round count of approximately 4000-5000 rounds, one bolt lug broke (adjacent to the extractor). This seems like a (relatively) short life for a bolt. I'm curious if you think the XH buffer and XP buffer spring likely contributed to the failure? In your estimation, is simply replacing the bolt going to produce a rifle safe to resume firing? Or do you suspect there may be wear on other parts that would warrant a rebuild and/or replacement of the upper? I’m fine with replacing other small parts, but it doesn’t make sense to re-barrel this old, non-adjustable gas upper if there’s a possibility the barrel extension is no longer safe.

I guess I’m seeking advice on, given the bolt failing as early as it did, if there may be a bigger problem and I should just buy a new upper? Or quit being a pansy and just replace the bolt and drive on. Thanks for your time.

 

[Cascade Hemi]

I have a PWS Mk 110 upper (.223 Wylde, non-adjustable gas) from circa 2011 or 2012 - sheared off a bolt lug yesterday.

I purchased the upper new and have been running a SiCo Specwar 762 suppressor on it. 99% of rounds fired have been suppressed. I ended up running an XH carbine buffer from HeavyBuffers.com (8.5oz) and a Wolff XP carbine buffer spring to reduce the amount of gas blowback.

Yesterday, at a round count of approximately 4000-5000 rounds, one bolt lug broke (adjacent to the extractor). This seems like a (relatively) short life for a bolt. I'm curious if you think the XH buffer and XP buffer spring likely contributed to the failure? In your estimation, is simply replacing the bolt going to produce a rifle safe to resume firing? Or do you suspect there may be wear on other parts that would warrant a rebuild and/or replacement of the upper? I’m fine with replacing other small parts, but it doesn’t make sense to re-barrel this old, non-adjustable gas upper if there’s a possibility the barrel extension is no longer safe.

I guess I’m seeking advice on, given the bolt failing as early as it did, if there may be a bigger problem and I should just buy a new upper? Or quit being a pansy and just replace the bolt and drive on. Thanks for your time.

Unlocking under excessive pressure caused the premature failure. The super heavy buffer is a symptom of over gassing. A new bolt should be safe but you may as well buy two unless you plan on fixing the gas system. Short AR's are already hard on bolts, when you over gas them they eat bolt lugs or break at the cam pin hole. If your gun were gassed correctly it wouldn't cycle with an 8.5oz buffer.

 

[supercorndogs]

Get an h1 buffer and an adjustable gas block.

 

[sawgunner2001]

To clarify, this is a PWS original generation upper. No ability to add an adjustable gas block (that I'm aware of).

 

[Cascade Hemi]

To clarify, this is a PWS original generation upper. No ability to add an adjustable gas block (that I'm aware of).

Is it a DI gun?

ETA: I see this is a piston gun. Buy a few bolts unless the updated adjustable PWS parts can be retrofit.