Don't waste your money. Just set your rifle on your sandbags, pull the bolt, line-up your bore with the target (start at 50 yards), without moving the rifle, adjust your scope to the same target. That should get you on paper...and then fine tune your scope settings.
Yeah...that is how I generally site in a scope. Problem is when I want to check the scope when I can't shoot a few rounds first. For example...last weekend I 4- wheeled over some pretty tough country - thought it would be a good idea to shoot a few rounds yesterday. The gun went from 1/2" group at 100 yards to 6" high and left.
I 100% agree - taking a gun to the range is the best way to test a scope...I just want to have confidence in my gun and scope if I can't sight in before I head out.
Jesus Christ the same yesterday, and to day, and for ever.
Our Lord Jesus said that as it was in the days of Noah and
also as it was in the days of Lot so it shall be in the days...
It's happening again!!! God sent to us His prophet, and His Word
to this generation and we once more are rejecting it as was prophesied!!! ---> As promised, God Sent His Prophet to us!
Bore sighters are rough zeroing tools that help make it easier to get the first shots on paper when actually zeroing. It is NOT a precison instument, in no sense of the word. That's why many people dispense with them and just go sight in at the range.
That said, an optical type bore sighter, one with a grid, does have a good use for hunters. Once the scope is adjusted to point of impact, stick the bore sighter on and carefully note where the cross wires show on the grid. Then, prior to going on a hunt, recheck to see if the cross wires are still at that point. If they are, you can go hunting with more confidence. I have an old Bushnell "Pro" boresighter and keep a card with the zero points of all my rifles in the case with the tool. This pretty much eliminates any lazer bore sight tool, for me anyway.