AR Lower Question

[Krinkov762mm]

Hello out there. I'm a newbie to the forum, but I can already tell I've been missing out.

I've got a question for all of you experts. I own a few ARs. Most are early Colt A1s and a post ban Bushmaster. I really enjoy my Colts, but there increase in value and collectability have reduced the over-all times that I shoot them now a days. I love shooting the Bushmaster. The A2 sights are very handy at the range.

Anyway, here's my scenario:

I've been thinking of making my Bushmaster strictly into a bench gun. I have a friend that is taking his competition POST ban Colt back to stock specs and he's made me a price on the various parts that he is taking off/out. I know that Colt changed the pin diameter on their lower receivers back in the early '90s and that those pins are larger than the early SP-1s.

Does the postban Bushmaster have the same over-sized pins as the post ban Colt or does it have the same size as the preban Colts? I don't want to pay for a two-stage trigger group that I won't be able to use.

Thnks for your input on this situation.

[HOLMES]

go here and have a good read
http://www.biggerhammer.net/ar15/

[Krinkov762mm]

Holmes,

Thanks for the link. It had some very interesting and helpful information. However, I didn't see a distinction for different size trigger and hammer cross-pins. Was I mislead into thinking that they made different size trigger group pin diameters during different manufacturing years, or are all trigger group cross-pin diameters the same and the only variations were in the upper and lower receiver pivot pin sizes.

Thanks for the help.

Krink

[HOLMES]

as far as i know all lowers are the same dimensionally--quality is another issue

[oclvtrek]

The Colt SP1s used the standard, mil-spec sized fire control pins. As a general rule, if you Colt lower has the large front pivot pin it will have mil-spec FCG pins and if your lower has the standard front takedown pin it will have the oversized FCG pins. Everyone else out there uses mil-spec front takedown pins AND standard, mil-spec FCG pins...except for Colt. Your Bushmaster lower is mil-spec is both areas.

I hope this helps

[Krinkov762mm]

Thank you gentlemen for the information and the help. :) Thanks oclvtrek for the distinction information. I appritiate your and holmes' help and advice.

Krink