Damn this thread has my interest peaked and has caused me to think and ponder how to be able to perfectly level a scope on any platform.
Now I've used the Level Level Level gadget on the rifles I've leveled the crosshairs on and have gotten away with it as I havn't run across a rifle it didn't work on. However, it appears that there is many this gadget wont work on that I havn't run across yet.
My gun vise has a level on it and adjustable legs that allow you to level the vise. So when you set the rifle in it and clamp the forestock and butt stock into it one might think the rifle is level but it's usually not due to imperfections in the stock or the way the action is set into the stock. As little as that tollerance may be one could not truely dead on level a scope with this gun vise alone. So that idea doesn't work either.
Leveling the scope off the scope base is not a guarantee either.
Not many rifles have a level spot on the reciever to level a scope off of.
Taking the rifle out of the stock to try to find a level spot on the bottom of the reciever may be sketchey as well.
Possibly with the barreled action out of the stock one could use the bottom of the recoil lug but I don't believe that the bottom of all recoil lugs are flat nor would they necessarly be level with the bore if they are.
Possibly with the trigger removed the slot cut in the bottom of the reciever for it to go through would give a good level from side to side of the open slot but I'm just not sure about this either.
There has to be a guaranteed method or tool / gadget that can accomplish leveling a scope dead nuts with any type of rifle out there.
I am truely ignorant of how this is accomplished with any rifle that one may run across and it's driving me nuts.
Hopefully one of the gunsmiths on this forum will chime in soon and give up the method, tool set, or gadget that will level a scope dead nuts on any and all rifles. My sanity is at stake here.