M203 mount for 733 Commando

[DE_Six]

Anybody has info about this mount? It looks like a shorter M203 PI, mounted on a 733 11.5", but the barrel ring/brace is missing.

Custom work, maybe? The shooter on the pic is a Recon Marine, maybe the FR armorers built it?

http://www.onpoi.net/ah/pics/users/519_1093118897_marinem203-pi.jpg

Cheers

[thatguy96]

I wish the picture had been shot from the other side, with the damn shadow I can't really tell how its mounted at all. Looks like its attached to a standard style round handgaurd, but like I said I can't really see.

...meh, and another pesky 11.5" gun with A2 rear sights, maybe Colt did make a batch of A2 rear sighted M733s too.

[DE_Six]

Yeah, I know it's dark. Never saw this setup ever again. I tried to make it a little brighter with PS, not much difference.

Maybe it's attached to standard M4 handguard lower half?

http://www.onpoi.net/ah/pics/users/519_1093124659_marinem203-pi.jpg

[thatguy96]

It appears to be locked into the handguard, but also to be rigged up to the bayo lug...which is interesting because M733 style guns don't have a bayo lug. You will notice a piece of the mount under the sight triangle however, which is what I'm getting at.

[DE_Six]

It looks as if it is attached to the barrel under the front sight tower

Here:

http://www.onpoi.net/ah/pics/users/519_1093130486_m4com.jpg

That's a narrow spot for a mount.

[thatguy96]

I've been bumming around looking for other things, but I stumbled upon mention of R/M Equipment (who apparently were first to introduce the M203PI or at least close). Their mount for the AR-15/M16 pattern looks close to this making me think this could be an in-house modified R/M Equipment mount.

[DE_Six]

I searched for R/M Equipment, didn't yield much. Only a Jane's website reference.

I guess it's in-house modified, as you said. I don't really get the point of putting an M203 on a 733, but who knows?

[pettifogger]

Colt has made some RO733 Commandos with bayonet lugs. However, that is not relevant. What appears to be a mount underneath the front sight block is the sling swivel swung forward.
http://world.guns.ru/assault/commando.jpg
http://www.gun-world.net/USA/M16/CAR/Latinforce1.jpg


The M203 PI (Product Improved) is a R/M Equipment (http://www.rm-equipment.com/) patented product. R/M Equipment is the only company that makes the M203 PI. The M203s (NSN #1010-00-179-6447) and M203A1s (NSN #1010-01-434-9028) in use by the military are made by a number of manufacturers including Colt, Knight's Armament Corporation, and Lewis Machine & Tools. The M203PI does not make use of the bayonet lug. You can read patent on the US Patent and Trademark Office (http://www.uspto.gov/) website. It is US patent number 4,733,489. The M203PI can be mounted to the handguard. In fact, R/M Equipment's literature includes a picture of such a mount. It is not a custom in-house modification, but one of their standard products.

http://www.stwing.upenn.edu/~wcchang/M203PI.jpg

[DE_Six]

Awesome find, pettifogger! :D

This was quite bugging me! ;)

Thanks guys, you two are the AR-15/M16/M4 wizards!

[thatguy96]

Petti, do you know if the M733s with A2 rear sights have the bayo lug? I've reversed my opinion on that matter (M733s with A2 rear sights) in light of serious evidence to the contrary, so now its the bayo lug issue. Also, do we know whether the A1 sighted M733s came first or second? I've heard that the Colt 733A had the A1 rear sights, but then again I've heard that the 733 only having A1 rear sights. I should probably move this question into the other thread...and feel free to reply there instead of here.

[pettifogger]

Here's that troubling picture of a RO733 with an A2 rear sight again. It does have a bayonet lug.
http://www.isayeret.com/weapons/assault/commando/colt-commando.gif

The RO733 is not made to a strict military specification like the M4 (MIL-C-70599A) and M4A1 (MIL-C-71186). Hence, Colt is a bit looser and uses whatever is lying around the parts bin. The RO733 with the A1 rear sights came first. In recent years, RO733s with A2 rear sights have been seen. I assume Colt has standardized on the A2-type receiver to reduce costs. For the same reason, Diemaco only makes flattop receivers now. There's an interesting post on how Colt haphazardly assembles firearms (http://www.ar15.com/forums/topic.html?b=3&f=14&t=164363) on ar15.com.

BTW, if you watch Black Hawk Down, you will see a lot of RO733 Commando with A2 rear sights.
http://www.stwing.upenn.edu/~wcchang/delta_team.jpg

[thatguy96]

That picture of that gun bothers me even more because of what looks to be a Type 1 Duckbill FH mounted too, though I guess it could be the Birdcage or A2 style and its just the picture quality. I think it would be safe to put Colt 733 entries into the table with both sight types and with and without the lug.