I purchased a NIB Colt factory 9mm carbine, model 3650, with 16" barrel and A-frame front sight several years ago (carrying handle model).  It had shiny hammer and trigger pins installed, which I always suspected was the result of some devious gun store employee or shenanigans of some kind.  

After deciding to sell my safe queen I did some research and learned that Colt had intentionally installed stainless steel pins because the pins had been breaking, from guns supplied to an LE/fed contract.  This was supposed to provide an easier visual of the condition of the pins, to see if the pins were deforming or broken, etc.

Colt also starting ramping the 9mm bolts, which helped end the issue with broken pins, since that was likely causing the broken pins anyway.  I'm not sure exactly what year this occurred.

Please chime in if you can confirm or deny of this.

Also, if you ever come across one of these for sale, please don't freak out and think the seller is lying to you lol

I have seen factory 9mm rifles with the shiny trigger pins.

Its true that the 9mm is hard on trigger and hammer pins. The stainless steel is an upgrade to allow the pins to last longer before breaking. It buys time, but does not fix the problem.

Look at the video on youtube regarding Colt 9mm rifles. Chris Bartocci has valuable input on this issue.

I'm curious that the breaking firing pins are related to using factory loads??  For most of us we're shooting loads with the power factor just over 125 for USPSA matches.  A much reduced load, in fact my 132 PF loads won't even cycle a 9mm handgun.  I have a little over 5,000 rounds thru my first AR9...don't see any problems with the pins as of yet.  Just thinking is all...................Thoughts?

Do you mean Model 6450? It sounds like it from the description you give. My Colt 6450 came with the 'RESTRICTED' markings and black pins in the fire control group.

Dave

As stated above....watch the Chris Bartocci video on the Colt 9mm SMG.  Must see video for anybody that's a fan of 9mm ARs

I broke the hammer pin in my M16 in under 500 rounds with a 9 mil upper.  I ended up ramping the carrier and switching to anti-rotating hammer pin.  Broke that one too.  I ended up having to go with a much heavier pistol caliber buffer and resigned anti-rotating hammer pin.  This has worked much better.

Jason

That video is priceless.  There is very little information about the Colt 6450 that I have been able to find.  I purchased mine from my brother many years back, a former LEO who picked it up in 1995.  It still shoots well and serves as the bedroom HD weapon, although I plink steel with it from time to time.  Had a red dot but I always fall back to my iron sights, mostly out of habit/training.

Other than Wikipedia, this is the only reference material I've found: www.smallarmsreview.com/display.article.cfm?idarticles=1326 .