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AR15.COM
AR Sponsor
2/21/2009 5:17:35 PM EDT
I have owned an ar-15 but never built one.  With all the craze I purchased a stripped lower and now plan on building it.  I have a question and I have looked around and cannot find the answer.

I purchased a S&W M&P15 lower and while looking around for a trigger group I found that they make large pin and small pin lowers.

I do not have anything to measure with other than a standard tape measure so tought to actually measure the holes but on the m&p they look slightly larger than on the bushmaster xm15-e2s model.  I cannot be sure though and that is why I am asking.  Sorry for the question if it is a dumb one but I don't know so I gotta ask.

Anyways my question is,  how do I find out what size pin holes come on that model of lower?
2/21/2009 5:33:24 PM EDT
[#1]
Welcome aboard... Most likely standard (small), .154in. Large are Colt style FCG at .190ish?? ~ .170in...
2/21/2009 5:42:54 PM EDT
[#2]
small hole, only Colt uses the larger holes for their trigger group.
2/21/2009 5:59:26 PM EDT
[#3]
Quoted:
Welcome aboard... Most likely standard (small), .154in. Large are Colt style FCG at .190ish??


Colt large pins measure 0.170"
2/21/2009 7:54:00 PM EDT
[#4]
Thanks to all who posted.  I wasn't sure and couldn't really tell by eyeballing it.

AR Sponsor