Colt AR Uppers and Lowers

[duartfarquardt]

I just acquired a Colt upper, post ban, with no bayonet lug, etc. I could care less about the bayonet lug, but I understand that some Colt ARs have small pins and some large pins. I need to acquire a lower that is compatible with my upper, and I THINK that I have a large pin upper. How can I tell, and how can I find a lower that is compatible? ANY advice is welcome.

Duartfarquardt

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[Redcap]

I just acquired a Colt upper, post ban, with no bayonet lug, etc. I could care less about the bayonet lug, but I understand that some Colt ARs have small pins and some large pins. I need to acquire a lower that is compatible with my upper, and I THINK that I have a large pin upper. How can I tell, and how can I find a lower that is compatible? ANY advice is welcome.

Duartfarquardt

Measure the pin holes.

 

[G1GRANDEUR]

they sell conversion pin also.

 

[duartfarquardt]

I should have included that the pin holes measure 17/64 inch. Just a hair over 1/4".

 

[eldbillbo]

Small pin. you'll know cause it will be the same size hole that is on the rear lug

so any lower will fit it except early colt lowers in which case you would need a $5-10 offset pin or bushing.