10-05-2022, 09:28 PM
(This post was last modified: 10-05-2022, 09:48 PM by lazyengineer.)
stonehog Wrote:Would I be correct in eliminating the carrier/buffer issue by turning off gas and firing a few to see if I get the ring? May be worth a try.
My expectation is yes. Though be aware one of the 3 Kabooms in the last year was with a bolt action rifle with that same brand brass. That said, it was with a casing that had been run 20 times or so, and one would think that to be a notable potential factor. A high-fire/resize count rerun factor that you are not facing. To do the refire test without the gas on, and see if that change alone fixes it with everything else the same, it would be ideal to run same load, same type brass, etc. Not sure if you really want to do that, or where your comfort level is on this.
Personally, after a catastrophic failure, I'm more along the lines of changing a whole bunch of stuff that might be contributors all at once. Your sectional tests and posts were helpful and appreciate you going to the effort. No real surprises there, TBH, but good to see confirmations all the same. From a scientific analysis standpoint, I'm curious to see what your no-gas test result looks like for sure, if you're willing to do it. My expectation is everything will come out looking fine, as the issue in question seems to arise when there is a combination of factors:
-too fast bolt-unlock (timing), plus
-excessively chamfered chamber entry (Odin and PSA perhaps?), plus
-brass with a more shallow head-design and so the first to be affected by the above two (apparently Lapua; though Starline also seems to have a high count of belt-formation complaints - though no kabooms there that I know of).
Mitigate any one of those and it seems to help mitigate the issue. Or so it looks like from the posting patterns on this issue. Curious to see what yours looks like when you eliminate the timing factor, by turning the gas off. You likely will need to fire more than one to get a lot of meaningful data, since only a portion of the brass in the original run exhibited the phenomena.
4x P100