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Biggy
08-04-12, 12:41
How important for accuracy is a good snug barrel to upper fit along with a upper receiver that has a true/square face for the barrel nut? I imagine the sloppier the fit and the more the face of the upper receiver is out of square the more accuracy issues your rifle might have.
420ollie
08-04-12, 13:22
It doesn't really matter. Trueing up the reciever face makes your zero near center on elevation and windage. Most barrel extensions fit snug in the receiver anyway.
Biggy
08-04-12, 13:37
It doesn't really matter. Trueing up the reciever face makes your zero near center on elevation and windage. Most barrel extensions fit snug in the receiver anyway.

But what if one had a barrel to upper fit like this guys?

http://www.youtube.com/watch?v=Wgw6MhO83Fg&playnext=1&list=PL4B0AC0DAB296AFE9&feature=results_main
warpigM-4
08-04-12, 13:44
Loctite really:confused: that would just melt out My Colt M4 barrel when i put into the Colt upper had No play it was a tight fit
MarkG
08-04-12, 13:45
But what if one had a barrel to upper fit like this guys?

http://www.youtube.com/watch?v=Wgw6MhO83Fg&playnext=1&list=PL4B0AC0DAB296AFE9&feature=results_main


That is a barrel extension O.D. and/or receiver I.D. issue. Has nothing to do with squaring the receiver face.

The video points out something else that can't fixed... stupid.
Biggy
08-04-12, 14:23
That is a barrel extension O.D. and/or receiver I.D. issue. Has nothing to do with squaring the receiver face.

The video points out something else that can't fixed... stupid.

I know that, but what effect would his sloppy barrel to receiver fit have on the rifles accuracy?
420ollie
08-04-12, 15:08
How loose is your barrel in the receiver?
bp7178
08-04-12, 15:33
It doesn't really matter. Trueing up the reciever face makes your zero near center on elevation and windage. Most barrel extensions fit snug in the receiver anyway.

Most barrels/uppers are on the loose side. The only uppers I've found that are consistently tight the the barrel extensions are the Vltor ones.

I've heard of bedding barrels to uppers before, but blue loctite is the wrong stuff to use. There are Loctite compounds for this, ie sleeve retainer 609.

Having a square receiver face is also important, but I think its more important that the upper's rail is true and square to the centerline of the receiver. The truing tools work on squaring the face of the threads to the centerline, but if the rail isn't lined up what difference does it make?

Long story short, if its an upper you expect or demand a high degree of accuracy from, use quality parts. If you're putting a 4 MOA red dot on it and will mostly be shooting it inside of 100 yards, it probably isn't going to matter.
Iraqgunz
08-04-12, 19:55
Use the search feature.