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.