When did Colt start using non-Mil-Spec-sized (ie. "large") pivot pins in their rifles?

Thanks

www.biggerhammer.net/ar15/coltcolors.html

The short answer is that the large pivot pins started the day they built their first civilian AR15.

As much as I like my Colts, what were they thinking when they decided on the large hole???

Probably they were trying to not make it easy for anyone with an M16 upper to be able to slap it onto a semi lower.   Kind of strange as the DIAS was not around nor were aftermarket parts.  Maybe this was a hoop that Colt had to jump thru for ATF?

In their early days, maybe they were trying to protect their military contracts by making it difficult for M-16 uppers to fit their commercial lowers. I dunno.

However the offset pivot pins, to mate M-16 uppers to commercial lowers, quickly appeared.



Lonny

The push pin type front retainer, and forward assist were both designed by the Army Ordnance folks, according to a Colt worker I talked with many years ago. (the very first Air Force M16s had a very different typr push pin).  Anyway, Colt felt they'd get on trouble w/the Army if they used the two items on their civilian model AR, so they designed the AR15 to avoid using either feature.

Also, as a side note, the very first AR15s had the hole for the disconnector spring in the trigger, and the notch in the disconnector in a slightly different place, so you couldn't cut the block out of the back of the trigger, and just insert the full auto disconnector.  Found this out after I'd had my early AR class 3d, and was going to keep the old trigger as a spare

Quoted: The short answer is that the large pivot pins started the day they built their first civilian AR15.

+1

Colt sucks. I sold mine and got something that was closer to mil-spec.