Trouble with handguard

[tomky]

My carbine's handguard will pop up after just a few rounds. I built up the carbine from a barreled receiver from the CMP years ago. The stock is a DGR. I have tried tightening the band screw and traded handguards... I wonder if the barrel band might be culprit, it may be a little out of square and is loose on the barrel itself. Does anyone know of a fix?
I was wondering if the ventilated metal handguards might be a remedy, anyone with experience with those?
Any thoughts would be appreciated. Thx

[GotSnlB28]

One of mine had a problem with the band slipping off the band spring, I replaced the spring and it was fine. Its probably that unless the guard lip isn't fitting under the barrel band properly.

[309Carbine]

In my experience, the commercial metal guards usually run a bit longer than GI guards. You can also bend the lip to gain a more positive contact with the band. I am not a big fan of the metal guards, just an option. Most wooden commercial guards also run a little longer. Make sure the nose of the band-spring is engaging the band notch properly. If it’s not seated, the band can move forward under fire.

Don’t pay $20 plus shipping for a ventilated steel guard.....think I have one in my stash.

[tomky]

I did try a new spring (not GI) and again hg popped off.
Roger, let me know what you would like for the metal hg and I will try that.
If that doesn't work I may try replacing the barrel band.

[309Carbine]

PM on the way. Can’t guarantee it will work, but I have one for you to try.

I sent you another PM with a deal you might can’t refuse...LOL.

[tomky]

Thanks Roger, that's a great deal

[GotSnlB28]

On the band spring: here's a picture with a (presumed aftermarket) problematic spring on the right, and a USGI spring on the left. The USGI spring has a sharp edge while the aftermarket does not.

https://imgur.com/a/BJC2Gli

[03man]

The band retainer is the likely suspect.

It is easy enough to put a sharp edge on a repro band, or help out a worn original,
just use a needle file and square it off.

Use a safe edge V file if you have one, and put a little reverse angle on it too- like a slight fish hook barb.

[tomky]

I did notice the difference between GI and repro springs and I have tried filing the repro to square it up. Thanks.

[mycanoe44]

On my "shooter" Std Prod carbine, I had to file the fish hook on the spring and add a couple washers under the clamp screw so it would clamp tighter and keep the hand guard from popping off.