Upper pin size

[belizejet]

When a company says it is a small pin upper does that mean they have different sizes. I want to get an upper that fits my lower and not have different pins/holes. I though they only had one size.

[Tim K]

There are two sizes. Most everything these days are small pin. IIRC, it was only Colt that used a larger pin size.

[belizejet]

Thanks amigo. Appreciate it. Almost pulled the trigger on an upper but wasn't sure.

[BPTactical]

There are two sizes. Most everything these days are small pin. IIRC, it was only Colt that used a larger pin size.

This would be a true statement.
There are offset pins available to mate a large/small pin upper/lower combo.