"It makes use of a propriety gas system that is not based on the Bushmaster piston or the piston system of any other company (the company has been careful to avoid using patented technology)".
It wouldn't matter in the least if they used the Bushmaster piston system simply because both Remington and Bushmaster are owned by the same company, (Cerberus Capitol Management). The Bushmaster piston system is produced for them by POF, (Patriot Ordnance Factory). In fact the Remington "R-25" AR-15 rifle is nothing more than a Bushmaster Varminter with a camo paint job. Notice how when the R-25 hit the market, so did the Bushmaster Varminter in camo? The only difference is one ships in a green box, and the other in a black hard case. Bill T.