Glass bedding an SMLE rifle

[CINDERS]

Whats expanding I could not see a 303 case expanding 3/4" either circumference or length with out a failure.
Are all the action screws tight also the trigger guard front collar may be too long this will then not allow the front of the receiver and barrel to pull down on the wood (My T had his problem and the whole action rocked back & forth).

You may also want to check the muzzle for damage and cord wear caused by numerous pull though application wearing out one spot on the muzzle.

Pull the rifle to bits and have a look at the recoil draws at the rear of the bottom wood they could be shot they are what the 2 legs on the bottom of the receiver rest against just in front of the trigger in the bottom stock they are angled at I think @70 degree's \ others will confirm (My T had that issue as well, yes I got done with it but sadly it cost a friendship.)

Others will be along also can you post some pics they are quite easy to upload..