Bushmaster AR-AR Push Pin: NOT RECOMMENDED

MAD DOG · September 18, 1999, 03:09 PM

I just got two of these, brand new from Bushmaster.
The part is intended to replace the big two screw bolt in the front pivot hole of Colt ARs.
They are slightly undersized, and allow a LOT more play between the upper and lower than the standard part.
The ends are not round at all.
The detent ball sits far enough out of the frame that there is about a tenth of an inch of lateral slop in it.
They will migrate out while firing. It took less than ten rounds to walk it out of the detent. Then the gun began to malfunction.
No big surprise there.
The ball detent is too small to detent effectively.
In short, they are JUNK.
They list at $9.95 each.
The box with two pins was sent UPS COD.
The bill when it got here was $32.40!
So it cost $12.50 in shipping and handling to get them here. Outrageous, even if a $5.00 COD fee is included.

Gun Plumber · September 18, 1999, 08:14 PM

MAD DOG,
The pin Brownells sells is also undersized but the detent works just fine. I too was disappointed and promptly sent it back!

Rosco Benson · September 18, 1999, 08:39 PM

Brownells sells two different sizes, .250" and .315" diameter. Perhaps you both are putting a small pin in a big hole. I've been using one of these for a couple years and have had no problems with it drifting in use (although I'll agree that the detent ball is too far out). I just put 100 or so rounds downrange this afternoon with a rifle so equipped. No drifting. No malfunctions. No problems.

Rosco

Gun Plumber · September 19, 1999, 01:36 AM

Rosco,
The .315 pin was in reality about .309 diameter. Too sloppy for my liking.

MAD DOG · September 19, 1999, 04:26 PM

The hole in the weapon is .315", the original pin is a tight fit at .315".
The Bushmaster parts are not round, and have an OD that measures between .309"and .312".
This seems to indicate that they are foisting off a 5/16" nominal sized pin that was NOT purpose built for the AR15.
"Hey, we can buy this with a parkerized finish, and pass them off as AR parts..."

My bet is that a check in the Reid Tool catalog that specializes in such items will turn up an exact duplicate of these at about $1.50 each.

Booooo Hissss.

[This message has been edited by MAD DOG (edited September 19, 1999).]

Rosco Benson · September 20, 1999, 07:11 PM

I suspect that the pin I'm using is of different parentage. Brownells lists the maker as DPMS. The pin I'm using is .250" in
diameter and nice and round. I don't think that it is some general purpose piece of hardware, because it has a head on it that is approximately .430" in diameter, with one side ground flat to butt up against the raised part of the lower receiver (which would contain the detent in a mil-spec receiver).

Given that Brownells stands behind their products, you might want to try their .315" pin for your application.

Rosco

September 18, 1999, 03:09 PM	#1
MAD DOG Senior Member Join Date: October 14, 1998 Location: Arizona. Posts: 853	I just got two of these, brand new from Bushmaster. The part is intended to replace the big two screw bolt in the front pivot hole of Colt ARs. They are slightly undersized, and allow a LOT more play between the upper and lower than the standard part. The ends are not round at all. The detent ball sits far enough out of the frame that there is about a tenth of an inch of lateral slop in it. They will migrate out while firing. It took less than ten rounds to walk it out of the detent. Then the gun began to malfunction. No big surprise there. The ball detent is too small to detent effectively. In short, they are JUNK. They list at $9.95 each. The box with two pins was sent UPS COD. The bill when it got here was $32.40! So it cost $12.50 in shipping and handling to get them here. Outrageous, even if a $5.00 COD fee is included.

September 18, 1999, 08:14 PM	#2
Gun Plumber Member Join Date: February 20, 1999 Posts: 44	MAD DOG, The pin Brownells sells is also undersized but the detent works just fine. I too was disappointed and promptly sent it back!

September 18, 1999, 08:39 PM	#3
Rosco Benson Senior Member Join Date: October 21, 1998 Posts: 374	Brownells sells two different sizes, .250" and .315" diameter. Perhaps you both are putting a small pin in a big hole. I've been using one of these for a couple years and have had no problems with it drifting in use (although I'll agree that the detent ball is too far out). I just put 100 or so rounds downrange this afternoon with a rifle so equipped. No drifting. No malfunctions. No problems. Rosco

September 19, 1999, 01:36 AM	#4
Gun Plumber Member Join Date: February 20, 1999 Posts: 44	Rosco, The .315 pin was in reality about .309 diameter. Too sloppy for my liking.

September 19, 1999, 04:26 PM	#5
MAD DOG Senior Member Join Date: October 14, 1998 Location: Arizona. Posts: 853	The hole in the weapon is .315", the original pin is a tight fit at .315". The Bushmaster parts are not round, and have an OD that measures between .309"and .312". This seems to indicate that they are foisting off a 5/16" nominal sized pin that was NOT purpose built for the AR15. "Hey, we can buy this with a parkerized finish, and pass them off as AR parts..." My bet is that a check in the Reid Tool catalog that specializes in such items will turn up an exact duplicate of these at about $1.50 each. Booooo Hissss. [This message has been edited by MAD DOG (edited September 19, 1999).]

September 20, 1999, 07:11 PM	#6
Rosco Benson Senior Member Join Date: October 21, 1998 Posts: 374	I suspect that the pin I'm using is of different parentage. Brownells lists the maker as DPMS. The pin I'm using is .250" in diameter and nice and round. I don't think that it is some general purpose piece of hardware, because it has a head on it that is approximately .430" in diameter, with one side ground flat to butt up against the raised part of the lower receiver (which would contain the detent in a mil-spec receiver). Given that Brownells stands behind their products, you might want to try their .315" pin for your application. Rosco