Firearm & Gun Forum - FireArmsTalk.com

Firearm & Gun Forum - FireArmsTalk.com (http://www.firearmstalk.com/forums/)
-   AR-15 Discussion (http://www.firearmstalk.com/forums/f20/)
-   -   what is pin size? (http://www.firearmstalk.com/forums/f20/what-pin-size-67695/)

GREGULON 07-05-2012 11:00 PM

what is pin size?
 
Looking for a 2 stage trigger and came across a RRA and the question of trigger pin size, a standard or long, so whats the difference?

Dillinger 07-05-2012 11:29 PM

Are you sure it was standard or "long" and not "large"? Standard pins are .154" in diameter, but Colt in their infinite wisdom produced proprietary pins that were tagged "Large" at .171"

There are anti walk pins that have been seen to be too "long" for some lower receivers. There was a set of pins that I got one time, and the "C" clip pin was a little long and caused a wobble. I don't remember the brand, but I think they were from Brownells.

I haven't run across a situation where a longer than average pin was specifically needed. :confused:

JD

X-mark 07-05-2012 11:37 PM

I believe Rock River has or used to have .155 pins, but I could be wrong. Standard size is .154. As Dillenger mentioned, Colt used to have .171.

treehugger49 07-06-2012 12:35 AM

Quote:

Originally Posted by X-mark (Post 860395)
I believe Rock River has or used to have .155 pins, but I could be wrong. Standard size is .154. As Dillenger mentioned, Colt used to have .171.

I assembled a lower last year with a RRA LPK, and the pins are .155. No big deal. A little tighter, but a little lube and a tap and they go right in - at least in my Mega Gator lower.

okdonk 07-06-2012 12:46 AM

Not sure for RRA. I had mine KNS anti rotating pins size 154 for my DD and Spikes lowers.

M14sRock 07-06-2012 06:10 AM

Quote:

Originally Posted by treehugger49 (Post 860467)
I assembled a lower last year with a RRA LPK, and the pins are .155. No big deal. A little tighter, but a little lube and a tap and they go right in - at least in my Mega Gator lower.

The .155s are slightly oversized (.154 is standard). That can help keep them from walking out.

Vikingdad 07-06-2012 06:37 AM

I just realized that I have a problem because I have a trigger out of a Colt with the .171" pins and installed it in my JDM lower with .154" pins. Do I need a new trigger?

Dillinger 07-06-2012 02:21 PM

Quote:

Originally Posted by Vikingdad (Post 860899)
I just realized that I have a problem because I have a trigger out of a Colt with the .171" pins and installed it in my JDM lower with .154" pins. Do I need a new trigger?

I believe Colt's bigger pin size were for the Takedown and Pivot pins, effectively making it impossible for you to assemble an "other" lower and slap a Colt upper on it.

I am not a Colt expert (or fan ;)) so I can't say for certain but I do believe that they only did this on those two pins, for a short period in production time, and that it did not effect your other pins.

As such I believe you are good to go Viking - you can always check and see if the trigger has any slop to it. If you shake the lower and it rattles like a baby toy, you have a problem. :cool:

JD

Quentin 07-06-2012 02:33 PM

Quote:

Originally Posted by Vikingdad (Post 860899)
I just realized that I have a problem because I have a trigger out of a Colt with the .171" pins and installed it in my JDM lower with .154" pins. Do I need a new trigger?

If the hammer/trigger pins are the large size they won't slide in a milspec stripped receiver. If they did fit you must have .154"pins from a fairly new or very old Colt.

ETA:
If you used small pins on the large hammer and trigger to make them fit then yes you have a problem.

Quentin 07-06-2012 02:42 PM

BTW, Colt went to the large pins before the 1994 AWB hoping to distinguish its commercial ARs from military/LE. Their argument was the large pin "sporter" models would not accept triggers and uppers from "evil" ARs. Didn't work of course and caused needless headaches. They went back to milspec size after the ban sunset.


All times are GMT. The time now is 03:40 PM.

Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.