The body of your No1 is just a tad - but only a tad mind you - tougher than mild steel so should be pliable/easy enough to open out in order to tighten up the bolt head. The same applies to the back end too, in reverse. It the bolt slops around like a sausage in the high street, then just crimp the rear in a heavy duty vice with vice clamps.
But DO NOT do this on a serviceable rifle