Is there any info on a piston 6.5 Grendel out there?

[mongoosesnipe]

Should be fine lighter loads may not have the gusto to cycle but you are not going to hurt anything although DI guns tend to be more accurat and I can't imagine the scenario of firing so many Grendel rounds without cleaning such as to warrant a piston set up

I seem to recall alexander arms having a piston driven upper on there web site at one point you may want to call and ask them about it