Upper hand guard flies off

HI Folks,

On my SP M1-Carbine, I have a problem where the hand guard (2 rivet) will occasionally fly off while shooting. I have tried to push the barrel band down as far as possible and have tightened the screw up as tight as I dare, but it will still come off occasionaly from the recoil. The reciever is sitting in the stock pretty tightly and I dont see any way of adjusting it that would make a diffence and I don't see any noticeable slop with the fitment.

Anybody else have this issue? What did you do to fix it? :help:

Thanks

Pictures please of both receiver where hand guard metal fits and hand guard front and back. Sumpin ain't right fo sho!

Here are a couple shots. As you can see, when the guard is in place and the front band is in place against the band lock, there is a noticeable gap on the tang that mates with the reciever. I have tried to pushing the band furthrer towards the reciever but that doesnt stay there long and it eventually creates the gap again. the back of the reciever appears to be in the stock solid with not play that is noticeable.

https://www.milsurps.com/images/impo...CIMG1580-1.jpg
https://www.milsurps.com/images/impo...CIMG1583-1.jpg
https://www.milsurps.com/images/impo...CIMG1585-1.jpg
https://www.milsurps.com/images/impo...CIMG1588-1.jpg
https://www.milsurps.com/images/impo...CIMG1581-1.jpg
Thoughts?

The space at the front of the band allows for the forward movement. If you changed the spring or the band you might eliminate the movement. Is it a manufacturer correct carbine? Do the specific parts matter?

Before you try to install the handguard (and with the front band out of the way), about how much of a gap is there between the underside of the barrel and the barrel channel at the nose of the stock?

With the front band still out of the way, how much do you have to raise the muzzle to allow the handguard to slip under the lip?

That would move the spring further forward. If it is in fact elongated I'd slip a matchstick in the hole and put the spring in BEHIND the stick, moving it back where it belongs and closing up that gap.

Would the wood drying out from age make it 'shrink' enough to make this happen? Would a good soaking in something help it to swell back up a bit creating a better fit? If so, what would be the process to do it right without hurting the stock?

Could be stretched a little, but that's not the cause of the problem at the rear. Anyway, the semi-pointed tip at the rear of the spring aligns with the centerline of the spindle (not its rear edge), so if the hole is stretched, it appears to be minimal. If it was as loose as first appears, it would fall out of the hole by itself. The back edge of the hole as we're looking at it should be 1/16" beyond the pointy tip of the spring. It's an easy matter to check how tight the spindle is in the hole by partially removing the spindle and rotating the spring. If it's reasonably tight, it's fine. If not, wrapping with tape or some other kind of shimming material should do it. The front lip on the handguard allows for some leeway as it's almost 3/16" wide.

Until the handguard can move back far enough to seat under the lip, the front band will be skewed and unable to bear fully on the stock and handguard front lip. Only after fixing the back end does the spring become a consideration. If it is loose in its hole, the effect would be to lose the pressure it applies to the underside of the band. That can be checked by placing a temporary shim under the spring in the slot in the stock to slightly raise the spindle out of its hole.

Most importantly, the OP needs to understand how the system works; then, since only he has the carbine in his hands and can determine by feel what's going on, can create his own a solution.

You might just try substituting another hand guard to see how it fits. That might be educational to see where the gaps are.

So i just swapped out the hand guard with another one I had laying around and it fits much better and has no noticeable slop. When I put the two guards side by side, one is almost 1/8 inch longer end to end then the other. Could this be from age shrinkage?

Also, Can you please verify for me that since my carbine is a Standard Products, and the guard that I started with which is marked S-HB matched my stock which is also S-HB, the new guard which is marked SJ is still appropriate for a 1943 SP?

Thanks