But if it is a bog standard .303" barrel RGG, which we think it is - in spite of assurances to the contrary, It's still shortened/cut back, free floating, L39 or 42'd - call it what you will, then any further work to 'improve' it is all academic because the harmonics are already down the pan it ain't going to shoot as accurately anyway. The best thing to do is to re-barrel the rifle and start again. If the old cut down barrel has a good bore, then have it machined down to No5 spec where it'll be marginally more accurate than it is now. That's only my 2c's worth based on nothing more than my observations