that plastic may melt if you get your rifle as hot as i do.

i prefer to pad the stripped gas tube in a vise and SLIGHTLY bend the retaining flanges together to better grip the wood. be careful! a little bending goes a long way.

the lower handguarda wobble or front to rear clearance is a little trickier.

first, make certain the forward retainer is slid all the way to the rear prior to throwing its' lock lever. as suggested, if your handguard has a tension spring, make sure it is exerting some pressure and re-bend it to suit. while slightly pinching the receiver is an option, applying epoxy or automobile body filler to the wood tabs that fit into the receiver and forward retainer is an easier and less drastic fix. again, a little extra filler material goes a long way. apply sparingly and save yourself loads of filing/fitting time.