Colt 9mm SMG clone help

[jaholder]

How did they secure the handguard cap in place with no gas tube? I though about tapping the gas tube port in the FSB and using a screw but open to other ideas.

Thanks!

[utahjeepr]

It's been a long time since I've seen a factory SMG. I swear they had that cap pinned in place somehow. Newer 9mm carbine I've seen (CMMG maybe) had a socket head screw.

Wish I could be more help. Mines got a FF rail, so wasn't a problem.

[D.O.A.F.S.]

My colt 6951 had a regular ar front sight post. I put a free float rail on it when I formed 1 it into a sbr.

[utahjeepr]

I think the SMG FSB is drilled for a gas tube, but not drilled for the retaining pin. I can't be sure though. I guess it wouldn't make much sense to go that far but not finish a standard FSB. Maybe oldtimers is getting the best of me.

[1168]

I don’t know how Colt did it, but a couple of other brand “mock Dissipators” I own use a screw into the FSB, and that seems to work well.

[81mmcat]

I used a roll pin in mine.

[hk_shootr]

I tapped the FSB gas tube hole and secured the ring with an allen bolt

[indianalex01]

How did they secure the handguard cap in place with no gas tube? I though about tapping the gas tube port in the FSB and using a screw but open to other ideas.

Thanks!

It’s definitely loose. I have 2 6991’s. One is FA.

[hk_shootr]

How did they secure the handguard cap in place with no gas tube? I though about tapping the gas tube port in the FSB and using a screw but open to other ideas.

Thanks!

I believe mine originally had just a roll pin to keep the end cap from rotating.
At a later date I tapped the hole and installed a 12-24x1/2 cap screw to secure the end cap.

The end result is like this.

2122D69A-5C6C-4176-900A-2DF3FF99B993.jpeg

[Deadman William]

if you have an old gas tube and roll pin, just cut it down and use it as a stud. if you dont like or dont want to tap the gas port