
Originally Posted by
SomeOtherGuy
CMMG's "WASP" treatment is also some form of nitrocarburizing.
Just to summarize and add a few, the list of currently marketed ARs or uppers with some form of nitrocarburizing treatment seems to be:
S&W M&P15 "Sport" model
CMMG - LE Series with WASP treatment
DS Arms (most ZM4 models and ZM4 uppers, but they also offer plain CM and chrome-lined on certain styles)
LWRC
POF-USA
AAC
Adams Arms (uppers)
Huldra Arms (rifles and uppers with chrome-moly barrels {not stainless})
Bushmaster ACR (no other models)
Sig - 550-556
Superior Barrels with "hard blue" (uppers and barrels) {http://www.superiorbarrels.com/}
From the list above it seems that this treatment is used by inexpensive models on the one hand (S&W, CMMG, DSA) and boutique more expensive models on the other hand (all others), and as far as I know is not currently used on a mid to high end upper in an ordinary DI AR-15 configuration, with the sole exception of the uppers from Superior Barrels, on which I have no reputational information.
Fabius, I couldn't find any information about an "SA58 CTC" on DSA's website or on google. I know that DSA had been offering nitride treated L1A1 barrels for a brief period of time, but apparently not right now. Do you have any more information on this model? Most of the SA58 models have a 4150 steel barrel that is cryo treated but not, to my knowledge, given any surface treatment like chrome or nitriding.
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