ar 15 trigger pin size

[yotesmoker]

Have a ar-15a3 tatical carbine and want to have a better trigger put in.I contacted colt with the ser # but they had no record...[LBD 026xxx]Two different smiths gave me 2 different sizes.Trying to find when gun was mfg.It is also a law enforcement ar if that makes any difference.

[rockapede]

Do you have access to a set of calipers? That would be the easiest way to know for sure.

[GH41]

Nevermind.

[JasonB1]

More than likely, if it has a front push pin it uses small hammer and trigger pins. If it has a front screw in lieu of a push pin it is more than likely a large hammer/trigger pin. Calipers are the best bet though....or just compare them to anon Colt which should all be small diameter.

[titsonritz]

A little trick I learn from IG, a quick way to check hammer/trigger pin holes is to use a firing pin. Remove the hammer and slide a firing pin into the hammer pin hole. You should feel it move against the inside of the small pin hole (.154). If it is a .169 (large pin) then it will be sloppy.