AR-15 platform: gas piston, or gas impingement?
Am considering an AR-15 style rifle, but specifically want to understand the pros/cons of one specific system, at this point: the gas system.
In particular, I would like specific feedback from folks that have direct experience with either (a) a standard AR with gas-impingement operation, or (b) a variant AR with gas-piston operation, or (c) both.
To my way of thinking, dumping hot and dirty gas from the end of the barrel into the action mechanisms doesn't seem a very smart thing to do. Yeah, I know: the troops have used this for a long time. A number of companies are trying to address this one aspect of the AR's operating mechanisms.
There are alternative gas-piston systems out there, notably AR-15 class rifles by Olympic Arms with their OA platform rifles, Patriot Ordnance with their P-415/416 rifles, the Robinson Arms XCR, and the Leitner-Wise CP and SOC rifles.
Questions, for both platforms:
- At what point during shooting does your gun dump get fouled such that it absolutely requires cleaning (if you've hit that limit)?
- Have you ever gone 500rds without cleaning out the relevant fouled (action/chamber) areas on your gun without a failure?
- What, if any, difference in reliability have you found in the gas-piston variant versus the standard AR-15?
- Which would you pick and why?
For sheer sense of design and the potential for improved reliability and durability, I'm leaning toward the gas-piston variants. However, other than Olympic's system, the others are relative newbies on the market with their gas-piston systems, and I'm not too fond of being a guinea pig.
Let 'er rip.
Related note from John Farnam