[ARCHIVED THREAD] - Colt lower/upper fit

Posted: 8/21/2008 5:30:29 PM EDT

I have an early 90's Colt HBAR lower. I just purchased an early Colt M4 marked upper. The upper is a slightly lighter gray than the lower. After receiving the upper I test fitted the two to check the color match and there wasn't a problem. It uses the front push pin with the screw. Now that I have mounted a Colt 14.5" SOCOM barrel the upper and lower will not go together. I was able to get both the front and rear pin in, but not at the same time. I applied quiet abit of force but didn't beat on it. Has anyone had this problem or heard of this happening before? Any suggestions?

Thanks

Posted: 8/22/2008 6:29:31 PM EDT

[#1]

Is your full circle bolt hitting the sear block in the lower ?

Posted: 8/22/2008 7:03:40 PM EDT

[#2]

Quoted:
Is your full circle bolt hitting the sear block in the lower ?

First thing I thought also.

Pull your bolt and carrier and try to put them together.

Posted: 8/27/2008 8:12:58 AM EDT

[#3]

Thanks for the help guys. It turned out to be the buffer tube. I just backed it out all the way possible and it works. I ordered a new Vltor tube. I have noticed on some other tubes that they were filed at an angle. Is this a common problem/fix?

[ARCHIVED THREAD] - Colt lower/upper fit

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[ARCHIVED THREAD] - Colt lower/upper fit

[ARCHIVED THREAD] - Colt lower/upper fit