Hello fellow user, I am here to ask you all for your humble opinion on a Piston upper. I currently own a PWS piston upper with a 14.5" barrel and permanent pin FH. I am thinking of getting another piston upper but don't want to be stuck on a Proprietary set up, I want to be able to change out rails with the new ones coming out or already out. If any of you have any expirience building from the diffirent piston uppers stated above then please throw out a few choices to help me decide on the practicle or econimical route to take, the  ADDAX's new ZK is nice, but I read a lot of good reviews on the ADCOR, LMT and STAG uppers. Which would be a good pistion upper with the easiest and most Customizable of the four uppers? I really would prefer the barrel to be 16" with the FH already installed and that was the reason I chose the 14.5" barrel. any feed back would greatly be appriciated - Thanks

my vote is with the LMT.  Mine has been 100% reliable.

I highly recommend the LMT piston.

The rail may not be able to be changed-out, but it does sure give you a really nice, solid, sturdy rail.

Plus there are now companies able to fab up custom barrel extensions, to use other barrels with the MRP CQB upper, but it would definitely help for LMT to start selling the piston gas block separately.

The LMT was going to be my second choice over the ADDAX only because I currently have the ADDAX upper with PWS long stroke piston set up. I love it and it shoots very well but ADDAX no longer have the 14.5” barrel offered on their new ZK line that’s due out soon, I may have to think about your suggestion on finding shops or vendors out there that can make rails to my specific liking, my PWS is great but want to venture out to a non proprietary system as far as AR furniture is concerned.

Have and love the MRP but I might have to get an Adcor upper some day also as Id really like a piston 300BLK with variable gas.

Yes, I emailed Chris, he is very responsive to my emails and I also hear that there is going to be a delay due to DD barrels but Chris had already emailed me that the 14.5” barrel can’t be done on the ZK hence the reason why I am here asking you all for advice on another piston upper choice.

Addax is definitely the way to go. I called and talked to them about my upper that I was thinking about and they were absolutely awesome. I'll go back to them any day of the week for uppers or rifles.

I agree, that’s why I made ADDAX my first choice since I already have an atac gpu built by them but wanted to get their new ZK line in a 14.5” barrel (not possible per Chris) I guess that’s the only thing stopping me since I can see that they have a Samson rail installed on their prototype, I may be able to switch out the rails at a later time versus the atac gpu I got from them that use a proprietary rail built by PWS’s long stroke piston. I saw first hand the ADCOR BEAR’s piston system at the shot show and was told that if and when the uppers become available it “might” be at the $1000.00 range….not bad at all. The folks at ADDAX are awesome with their customer service….Just wished that they would hurry up and put out the ZK line (drooling) soon.

Almost there.



Just taking care of some stuff with the coating company and waiting on a few DD Cold Hammer Forged Barrels.



We are looking into releasing a 14.5" model with a pinned and welded flash suppressor or comp right now, since we have received quite a few requests for this configuration.  If we do offer one, it will not be until Summer 2011.





 

Well….if that’s the case then there is no more need to continue this post because I always had my mind set on the ADDAX with a 14.5” barrel. I am willing to wait this summer for it. Thanks to all who threw in their two cents on the recommendations for a piston upper I have shot a few on the list I posted and they all shot very, very well and would have no qualms in buying one of the others but I will go with the ADDAX ZK when it comes out. Thanks again to all