The Firing Line Forums - View Single Post - Barrel Threaded - Problem With Re-assembly

cjw3cma · January 21, 2008, 02:53 PM

Sent my 18-1/2" 870 barrel to Mike O. to be threaded (he did a great job and fast too) and now for some reason I am having problems re-assembling (Model 870™ Express® Synthetic 7-Round).

The magazine extension seems to bottom out before the barrel is tight to the receiver; there is at least a 1/4" space left. I don't know what is up as it came apart normally but I can't seem to get it back together again (and I have taken it apart before without a problem).

Are there any words of wisdom before I humbly take it to my gunsmith for (proper) re-assembly? Here's some pics to better describe my "situation" -

1. The barrel is seated properly as seen here:

2. When seated properly, the exposed threads measure: .359

3. The thread depth on the (factory) extension - .325

So when I install the spring and attach the magazine extension, I'm left with a gap (.359 - .325 = .034).

[color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color]? What am I missing here? This has got me stumped.

[Posted on more than one site to maximize possible replies]

January 21, 2008, 02:53 PM	#1
cjw3cma Senior Member Join Date: July 9, 2007 Location: Chiloquin, OR Posts: 217	Barrel Threaded - Problem With Re-assembly Sent my 18-1/2" 870 barrel to Mike O. to be threaded (he did a great job and fast too) and now for some reason I am having problems re-assembling (Model 870™ Express® Synthetic 7-Round). The magazine extension seems to bottom out before the barrel is tight to the receiver; there is at least a 1/4" space left. I don't know what is up as it came apart normally but I can't seem to get it back together again (and I have taken it apart before without a problem). Are there any words of wisdom before I humbly take it to my gunsmith for (proper) re-assembly? Here's some pics to better describe my "situation" - 1. The barrel is seated properly as seen here: 2. When seated properly, the exposed threads measure: .359 3. The thread depth on the (factory) extension - .325 So when I install the spring and attach the magazine extension, I'm left with a gap (.359 - .325 = .034). [color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color]? What am I missing here? This has got me stumped. [Posted on more than one site to maximize possible replies]