Correct front sight for fixed colt commando front sight post?

[The Dumb Gun Collector]

Guys,

I picked up a surplus a1 commando upper from botach. The thing is great but it has a dead tritium front sight. I was thinking of replacing it can you tell me which one is correct? This one is a 11.5 with a1 carry handle.

[MountainRaven]

Likely depends on when it was manufactured, so either an A1-type or an A2 would be correct, I'd think.

[mack7.62]

I would think it would depend on the barrel twist not that it really matters for shooting, so A1 round for 1/12 and A2 square for 1/7.

[bamashooter]

Believe the actual A1 XM177 model had the .040 over round post.

[The Dumb Gun Collector]

Maybe this will help

https://live.staticflickr.com/65535/49483984502_100c9bc170_k.jpg (https://flic.kr/p/2ioJmAA)C626D53A-B0B5-4360-A1F4-3077B97D28A1 (https://flic.kr/p/2ioJmAA) by stoiclawyer (https://www.flickr.com/photos/52942291@N00/), on Flickr

[The Dumb Gun Collector]

I’m setting it up as a doomsday KISS gun. I’ve been looking for one of these colt uppers forever. I’m going to put a scout mount and a new tritium front and call it a day.

[MountainRaven]

I would put an ACOG on top of it, but that's me.

[scottryan]

You have a 733 upper. It should have a Colt tall square carbine post.

[jsbhike]

I didn't unscrew it to measure it, but AR-101 appears to be the same height as front sight post 1005-01-134-3625

https://ameriglo.com/collections/products/ar-15-tritium-front