I am moving this here so I can get more traffic on it...
I did a SBR build about two years ago.During the course of the build, I noticed the pin holes in the upper receiver did not perfectly line up with the push pins in the lower receiver. To get the rifle put together without sending the upper back to the manufacturer, I did a slight dremel job to open the front pin hole up in the upper so it would pin together. I stretched the front hole by about the thickness of 2 or 3 pieces of paper.
The dremel job worked and the rifle works great.
I have noticed that if I push hard enough on the upper and lower from the side (while assembled and pinned) I get a tiny amount of movement at the front lug. My concern is that down the road this slight movement could damage my SBR lower by wearing it or causing cracks to form.
Should I just not worry about it, or is this a valid concern and should I replace the upper receiver with one that fits properly?
Pics of said SBR, ignore the circled area (that was from another thread long ago):
Posted: 12/4/2009 8:47:01 AM EDT
[#1]
Should have opened up the take down hole vs the pivot hole. Anyway, it should be fine, not worth spending money on this. BTW, if your lower is out of spec you could have the same problem with a new upper.
Posted: 12/4/2009 8:49:15 AM EDT
[#2]
What brand upper and lower?
Posted: 12/4/2009 8:52:16 AM EDT
[#3]
I dont know if I'd worry about it as long as there isnt any wear in the rear where the bolt carrier hits the carbine buffer.
But Id probably SBR another lower just in case.
Posted: 12/4/2009 11:04:17 AM EDT
[#4]
BTT.
Posted: 12/4/2009 11:08:07 AM EDT
[#5]
stripped uppers are cheap, go for it.
Posted: 12/4/2009 11:10:25 AM EDT
[#6]
basic cheap ar15, shoot it till it will not shoot anymore then buy another.
Posted: 12/4/2009 11:20:57 AM EDT
[#7]
Slowly start building a second.
Posted: 12/4/2009 11:21:59 AM EDT
[#8]
Quoted: basic cheap ar15, shoot it till it will not shoot anymore then buy another.
once something becomes NFA it is no longer cheap or basic
get a new upper, they are cheaper than replacing an NFA lower should the unlikely happen
Posted: 12/4/2009 2:49:19 PM EDT
[#9]
I need more votes on this.
Posted: 12/4/2009 2:54:41 PM EDT
[#10]
Rubber o ring around the pivot hole in the upper. Try it, see if that eliminates the wobble.
ETA: Like this.
Posted: 12/4/2009 3:14:25 PM EDT
[#11]
stripped receivers are cheap
Posted: 12/4/2009 3:20:37 PM EDT
[#12]
Quoted:
stripped receivers are cheap
Yep.
No need to replace the whole barrel, extension, FSB, gas tube, etc. Just swap out the one part.
Posted: 12/4/2009 3:24:27 PM EDT
[#13]
Quoted:
I need more votes on this.
Are you sure whether it's the upper or the lower that's out of spec?
Posted: 12/4/2009 8:45:16 PM EDT
[#14]
Quoted:
Quoted:
I need more votes on this.
Are you sure whether it's the upper or the lower that's out of spec?
....which is why I asked what brands the upper and lower were before giving my opinion.
OP, answer the question.
Posted: 12/4/2009 8:47:09 PM EDT
[#15]
It sounds like its just fine. Does it bother you when you shoot it?