Hey guys,
Well last night I assembled my very first AR lower and I am very pleased with how everything fit together. I had to be a bit patient waiting for parts to come in and I kinda went with all upgraded parts for my first. Installing the detent for the front take down pin was surprisingly easy despite everything I read on the net. The hardest part was probably pushing the hammer pin though as I was thumbing the hammer into place against a lot of spring pressure.
The question I have is related to my buffer tube/buffer retainer.
I am running a BCM mil-spec tube with an H-buffer and an RRA LPK.
While screwing the tube into the receiver, it comes short about 1/8th of a full revolution before hitting the nipple of the buffer retainer. When I backed it out a full turn, I noticed that it barely captures the retainer. With the stock fully collapsed, there is also an annoying small gap between the castle nut and the front of the stock. The end of the tube is also noticeably recessed into the back of the receiver. Here are some pics:
I removed the buffer retainer and reinstalled the tube and everything and made that last 1/8th of a turn just to see how everything would fit. The end of the tube comes exactly flush with the edge of the top of the lower and the stock closes quite nicely with just a hair of extra space.
Basically everything looks like it would fit a lot nicer if I managed to get that extra full turn.
It doesn't look like the tube is protruding too much from the centerline of the buffer retainer nipple. Maybe like a 64th of an inch. I am thinking bout filing a small notch or just filing down the extra portion of the tube (coming out only at the base of the tube area) hitting the nipple.
What would you guys do? leave it? do it? I heard only commercial tubes have that notch and i'm the kind of person who always wants to keep everything "standard" but i'm guessing my lower/parts are somewhat out of spec here and there which is amounting to this issue. I just wanna make sure I don't screw anything up as I've put quite a lot of money into this lower already. Is there anything wrong with having the front of the tube resting exactly flush against the edge of the lower? or is it supposed to be recessed into the threaded portion a little bit?
Thanks!








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