to be honest i think cutting the front would be a waste of time as it would save very little weight.
cutting it at the butt end is the way to go not that it will again lose a lot of weight but it will bring the gun closer to the shoulder making it feel lighter,tighter into the boddy.
if you make a nice clean cut you could always rejoin the disgarded peice at a later date,sanding down the join making it look half decent and certainly useable.