I'd like to convert my 6944 upper to the piston version P0923.
Sharkarms has the BCG's for sale fairly often, but I can't locate the rest of the parts I need. Does anyone know where these parts can be located?

Why??

There has always been a lack of parts available for the Colt piston guns. I remember awhile back a member was seeking help to find replacement piston rings for his carbine.
Colt was unable to help, and I believe he is left with a non functioning gun.

I’d leave it as is.

The correct answer.

Why? Because I want too... I've got several AR's that are not part of my usual rotation and I just wanted something different.
Thanks for your time.

Replacing the pinned GB would be a PITA..

As mentioned...yeah, you can occasionally find some parts, but finding a gas block, piston, the piston rings, etc...good luck. Colt barely sold them when the gun was in production; they might still have some parts kicking around their floor for repair/replacement purposes on customer/contract guns, but other than that you'll just never find all the parts you need.

Having owned a 6940P..other than "neat" and a pretty good gun by itself, it really didn't have the features you actually needed on a piston gun; namely the ability to run in a suppressed setting. The whole point of a piston gun in an AR format was for the edge cases of running lots of ammo quickly with a can on; something the standard layout doesn't really do very well, but the piston version chugs right along with.

It's a shame, the rifle itself was actually IMO one of the better piston versions out there...it was just missing what it really needed to succeed, and they didn't have much interest in making it succeed in the first place it seems.