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.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.
The .155s are slightly oversized (.154 is standard). That can help keep them from walking out.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.
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 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.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.
JD
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.
I was under the impression that the takedown pins were the only ones that differed in size, but I was wrong. The parts I have have the .250" takedown pins but the larger .171" trigger pins. I picked up some of the smaller pins at a LGS but didn't think about the trigger being the same .032" size holes (facepalm).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.
The milspec standard is .154", that is what you need for the vast majority of the lowers out there, unless you have a Colt receiver with the .171" trigger pin holes. They also make .1555" pins (I have seen that Rock River makes these) which you can jam into the .154" holes which is supposed to prevent the pins from rotating I guess? but they make anti-rotating pin sets as well so I would be inclined to use those rather than an oversize pin set.Yeah yeah but what's the difference.