[Justinmd]

I'm glad your rifle runs great, however, I'm not following your correlation with a one piece bolt assembly and cracks in the bolt. The bolt has always been one piece on every AR style rifle ever made, one piece plus the ejector and extractor and the gas rings. The bolt carrier, on the other hand, was two pieces and several companies have now made carriers with the gas key cut as integral to the carrier. I personally see this as a waste of material, but for some reason they went with it. Is it a marketing ploy or were they really having problems with the gas key coming loose on the piston guns? If they were really having problems with the gas key coming loose, that undermines your profession of LWRC reliability.

In either case, this has nothing to do with cracks in the bolt head, which I'm assuming you mean to be the bolt lugs. Bolt lug failure has been a problem in just about all the military tests (abusive type tests) I've seen of the AR style rifle. LMT and KAC both came up with a claimed "improved" design with features that prolonged bolt life but I have no first hand knowledge of the veracity of their claims, maybe LWRC also came up with an improved bolt to go along with their one piece bolt carrier. In any case, my M4 and those of my teammates never malfunctioned, so there's precious little room in our case for the LWRC to vastly outperform an M4.

Really, you should ponder for a moment how it could be the case that an M4 with a piston (LWRC) could outperform an M4 with DI with any significance. The bolt, carrier, extractor, ejector, buffer etc etc are all generally the same. Really the main change is what forces the carrier rearward, is it an off-axis push from a steel rod, or is it an on-axis push from expanding gases. Everything else is just tweaks to springs, clearances, chamfers, fillets etc. LWRC has undoubtedly done this, but so has the .mil, at least to SOF rifles. It sounds like you are comparing a relatively new LWRC to a worn out military M4. Be wary of calling an anecdote "proof", not that you are definitively doing so. I guess you would have to give a detailed account of the failings of your M4, which would give us all insight to the root cause of the problem.

As for your out-of-battery, the AR rifles (and others) are designed to not allow this to happen, i.e. the firing pin cannot reach the primer until the bolt is in battery. Just because the carrier wasn't fully forward doesn't mean the rifle was not in battery. An out of battery ignition will do many very bad things to what was once your rifle, not to mention body parts. If there was any significant rotation of the bolt, allowing the bolt lugs to engage the lug abutments, then things should hold for one regular pressure round. Keep in mind the cam rotation on the AR bolt is only 22.5 degrees, meaning even small amounts of rotation will result in at least partial lug engagement.

Keep in mind I'm not saying LWRC (or others) hasn't improved the rifle, as I mentioned before, there was room for improvement. Just don't think that their improvements have interdependency with their re-engineering of the gas system. In fact, the case could be made that their rifle would have been better if they made all their enhancements but kept the DI gas system. Certainly the concerns over localized heat buildup, op rod breakage (other brands), and weight/balance disruption would be nullified.
Justin