Hey folks, I'm hoping someone here can help me out. So far my search has been absolutely terrible as I have had zero luck. In an effort to get my rifle to run cleaner I have decided to try and find a piston system for my Colt LE6940. Unfortunately because of the rail design I'm not having any luck. Does anyone know of any drop in piston kit that is compatible with this model Colt? I'm getting pretty desperate here, I just got off the phone with Adams Arms and they said that they're piston kit was too large and would not fit. I can't afford a new rifle or even a new upper at this point which is the whole reason why I want to just find a drop in piston. Anyone have any ideas that could help me at all? I'm definitely in a pickle here and I could really use some help, thanks.

Have you looked at:
Osprey Defense
Bushmaster's retrofit kit

Would you consider selling the upper and just buying a Adams Arms/LMT/LWRC/PWS piston upper or putting the funds towards a custom upper build with piston kit?

I think you'd be better off just selling it and turning the money over on an Adams upper. You should get close to the amount back if the uppers in good condition. Or just sell the rifle as a whole and buy an Adams upper and seperate lower.


Rainier / Adams

Lowers

I don't think there is any piston kit that will work with that upper.  You could remove the gas block install the kit onto the gas block first and slide it back onto the barrel.  However, if the AA doesn't fit with that rail, chances are the other ones won't either.

You can always get a fail zero basic kit and keep it DI.

As the others have mentioned, selling and purchasing something else be it just the upper or the entire rifle is probably your best option if you want a piston AR.

It's worth a shot and I suppose I could sell the upper, just was planning on trying to keep it as the entire Colt. I don't want to sell the entire thing because A: I was just on gunbroker, and brand new versions of the rifle were not getting bids even, much less used; and B: dealing with FFL's in Illinois is a pain in the but selling the upper is an option. Don't suppose you know any other manufactures with the same specs or better for an upper barrel as a Colt would ya?

start saving your money and build an upper . You can buy each piece a little at a time . Then you can swap back and forth as you wish.

I wouldn't worry too much that the Adams barrels are poor quality. From what I've seen there not at all. People seem to be very happy with them and you can always talk to Adams or ask them about the barrels in their forum in the Industry section here on Arf. You could also buy a Sabre/Adams upper though, whether from Sabre or the Mega/Adams/Sabre upper sold. Or build from scratch. I'm at a misunderstanding if you're saying you'd have to deal with an FFL for selling and buying an upper in Illinois. That's just crazy if that's the case. I knew there are reasons I didn't want to move there.

Sabre Defense/ Adams uppers