Confirm Action

Are you sure you wish to do this?

Confirm Cancel
User Panel

Page AR-15 » AR Discussions
AR Sponsor: bravocompany
Posted: 5/10/2003 6:23:33 PM EDT
 I was talking to a guy online today that was selling a rifle, (DPMS lower and a Bushmaster upper). Says he cant get the rear pin to push in and lock. He sent a  closeup pic and it appears that the receivers lack about 3/32 from mating up. Is this normal with this receiver combo?
Link Posted: 5/10/2003 7:00:14 PM EDT
Somebodys' CNC is slight out of spec. AR/M16 parts should all readily interchange as long as std dimensions were followed.  
Link Posted: 5/10/2003 7:04:47 PM EDT
I dunno. My DPMS lower takes my Rock River and Colt uppers just fine; but then DPMS uses parts from different suppliers, so it is possible that one of those pieces is out of spec.
Link Posted: 5/12/2003 9:45:08 AM EDT
I just put together a Bushmaster VMAX flattop upper receiver and a Rock River Lower. They didn't initially fit together in that the rear lug of the upper didn't seat all the awy into the lower. Rock River explained that although mil spec, there are variances that occur and a 1/1000th of an inch may cause the problem. RRA suggested that I tap the upper gently with a rubber mallet, and after doing so carefully and working the connection with oil, I have a lowe to upper fit that is flawless.
Note that my Bushmaster A2 upper fit in the RRA lower without any difficulty. There rae slight variations in machining. We aint building rockets, ya know.

Eternal vigilance is the price of Freedom!
Link Posted: 5/12/2003 12:54:46 PM EDT
is it a preban lower (under SN10300 [no letters or prefixes]for dpms i think)?  i have a BM upper and of all my dpms lowers (3 of them) only the preban (cast) one does not fit.  you can tap it in with a punch (lightly so you don't mar it up) or a rubber mallet (what i use).  i think it has something to do with the gear they got from Essential Arms.  i've heard this is a common problem on thier prebans.  you can also dremel the pin so it goes in easier.  i wouldn't screw with the upper much as it would be harder to replace.
Page AR-15 » AR Discussions
AR Sponsor: bravocompany
Close Join Our Mail List to Stay Up To Date! Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.

By signing up you agree to our User Agreement. *Must have a registered ARFCOM account to win.
Top Top