[RPKESQ]

Conversions are in most cases dependent on two factors: engineering and quality.

Most AR-15 parts makers are not equipped with an engineering staff and lab like the manufacturers themselves. Quality of parts is another issue. How many parts makers can test to destruction repeatedly and use the data to re-engineer successfully (see point #1).

I am not a fan of trying to convert an AR-15 Stoner system into a piston design. The receiver was never designed to be the rear guide for the operating rod. So some kind of bearing surfaces must be added. Nylon and plastic in most of the kits I have examined. Not great engineering there! Better to buy a piston design if that is what you want. The engineering is correct out of the box that way.



There are several choices for a great AR-15 piston design, Ruger SR-556, Sig 556 are two of the best.