u/Black_Coffee8207

I recently inherited this Colt HBAR, and I’d love some help finding information on it. I’m mostly curious if it came factory in this 16 inch barrel configuration. Any and all help is appreciated!

Of note if it helps, it has a sear block and the strange colt specific front pin.

Thank y’all for any help, I’ve tried my best on my own, but I figured that you guys could help!