Alright guys (and gals?) I have a doozy for ya: I picked up a damaged Colt upper receiver from a guy as an add on in a trade because I wanted it and he didn’t so it cost me nothing and its a Colt with the C mark and the damage came from being in a vise improperly (he said it was against the upper pic rail and in between the pin lugs… pics should show) while removing the extremely overtightened barrel and now it is ever so slightly twisted or “torqued” to where the carrier rubs at the rear and is at a slight angle when in the receiver. It also requires some opposite torque to get the rear takedown pin through the lower to upper but when it does go together is twists the receiver the opposite direction and seemingly works just fine but I want to see if there is a way to “fix” the mild twist in the upper as it is super tight to my Colt 11.5" barrel I just bought AND its, well… a COLT with the C mark. There is also some outward bend below the front of the ejection port (where the bottom of the receiver was secured in the vice, apparently) and I want to make sure that wont cause any untoward issues due to the 5.56 pressures…
I know if there is anyone who can help me its all you eggheads here on m4c.
Any help/options/guidance is MUCH appreciated! Let me know if you need more detailed pics.
pics coming in a moment
Regards,
Darrin
Overall side view with a bcg and where it stops due to the friction in the rear and the lightened part in the material below the port opening is where the slight bend is
If you look closely you can tell the carrier is rubbing against the right side of the receiver
The friction is enough that it keeps the carrier from falling all the way when placed vertically
Another view of the carrier and where it stops without a little push
In this you can see where there is a slight outward bend below the front portion of the material below the ejection port
Here you can see some of the damage that the vise teeth did to the pic rails.
Extra picture for more detail
And finally here is a pic of the bottom of the upper and you can see where the guy filed or sanded part of the upper below where the minor outward bend is. I don’t know why.
There’s NO chance you put a twist on 7075-T6 receiver, none. Every minute you spend on this is one you’ll never get back. Time to cut your losses and junk it.
Yeah thats what i assumed. I asked him how it happened and he used no attachment method. I was just hoping i could salvage it but oh well. Hey it was free lol
Not really a fix for that type of damage. Your best option is to go ahead and do what others have recommended. Scrap that destroyed upper and get yourself a BCM ‘demo’ upper, then enjoy.
Just curious…How tight was the barrel that the receiver was twisted that bad?
I dont know, he just said it was “average colt overtorquing”… Whatever the hell that means. I noticed that my aero upper has the same square forge marking but barrels just drop right in and isnt tight at all… But the colt one is super tight! Interesting how two uppers from the same mfgr can vary so much
The company that that forged the upper (as indicated by the forge marking) has nothing to do with the final machining of the upper.
People make way to big of a deal over who the forge was when they really have nothing to do with the final finished product. They just provide the solid chunk of aluminum forged into the rough shape of the upper or lower.