Seems like a simple question

How can I tll if my AR15 A4 upper is a large pin or small pin? I have searched (Im not very good obviously) the net for this simple answer and come up with nothing.

Cheers in advance.

You're talking about the front take down pin, right? The small pin is @.25" if I remember correctly while the large pin is @.3" and has a screw head on either end. I've got both but they're at home and I'm at work

Only Colt made the large pin guns, just like the large trigger and hammer pins on some of their lower receivers. The good folks at Colt seems to worry about the fallout should an M-16 hammer make it into an AR15 lower.

I just measured mine........ its .25". I always thought it was a large pin upper. Silly me.

quote:

Originally posted by p67:
I just measured mine........ its .25". I always thought it was a large pin upper. Silly me.

Is it a Colt? If not, it's a small pin for sure.

DPMS - Cheers.