My sporters aren't all bolt actions, some don't have free-floated barrels, some are pretty light too. The technique I use tends to be the same though, either zeroing or testing loads, and that is to hold the rifle in both hands, just as I would if shooting in the field, with my weak hand holding the fore end and the back of that hand on the front rest.
FWIW I've found that letting the fore end simply rest on the front rest, and even more so letting the rifle free-recoil, affects POI as compared to holding it, especially with light rifles. This should not be a surprise of course, given that a rifle starts to recoil before the bullet leaves the muzzle.
I pay particular attention to maintaining the buttplate on the same position, and fairly firmly against my shoulder (but not so firmly as to cause muscle tremor). I also pay attention to such other things as keeping my elbows in the same place, my trigger finger clear of the stock, my forward hand in the same position, and my cheek in the same position. I also watch to make sure that swivels etc aren't snagging.
FWIW I'm just as happy shooting from lying supported, using a sandbag or a daypack, as from a bench.
