SIG Talk banner
Cancel
  • Notice image

    SigTalk is a forum community dedicated to SIG Sauer enthusiasts. Come join the discussion about Sig Sauer pistols and rifles, optics, hunting, gunsmithing, styles, reviews, accessories, classifieds, and more!

MPX won’t go together

566 Views 5 Replies 4 Participants Last post by  littlejacks, 
V
So I have a Gen 1 SBR’d lower and I bought a MPX K upper and put an In Lead We Trust barrel on it. The new upper has a tail on the back of the recoil spring plate and it won’t go into the upper far enough to close the two receivers together and push the pins in. Even with the old barrel or even without the bolt and charging handle. It just won’t go in anymore. What am I doing wrong?
Reply
Save
Like
1 - 6 of 6 Posts
TacoJoe
This may sound stupid but is the recoil spring in backwards? The “tail” may be the Op Rod. Pics would be very helpful.
Reply
Save
Like
RoyConley
www.sigsauer.com

CARRIER ASSEMBLY, MPX, FREE ROTATION, CARRIAGE ASSEMBLY, BOLT, FIRING PIN, CAM PIN

CARRIER ASSEMBLY, MPX, FREE ROTATION, CARRIAGE ASSEMBLY, BOLT, FIRING PIN, CAM PIN
www.sigsauer.com www.sigsauer.com

The above link shows SIG MPX bolt carrier assembly, SIG website, and it comes with two tail pieces. One with a tail, assembled in Photo, and the other as a separate part in third photo.
Reply
Save
Like
V
OK, I need a different tail cap then. I got my assembly from a gun so it didn't come with the other style. I'll call SIG. Thanks for your help!
Reply
Save
Like
V
I might just grind it off
Reply
Save
Like
L
I might have a spare without the tab. Can check in a few hours
Reply
Save
Like
  • Like
Reactions: 1
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
SIG Talk
A forum community dedicated to SIG Sauer Pistols and SIG Sauer Rifles owners and enthusiasts. Come join the discussion about optics, hunting, gunsmithing, styles, reviews, accessories, classifieds, and more!
Full Forum Listing
Explore Our Forums
SIG Sauer Pistols 🙋‍♂️ Member Introductions Guns P250, P320, P320 X-5, M17, & M18 Pistols P365
Top