Assuming this is a bolt action I wouldn't buy one. Just bore sight it the old fashioned way. Mount the scope, making sure the vertical axis of the scope aligns with the centerline of the bore (there are some tools that make this step easier, though, admittedly, some boresighters also help here).

Best to do this at a range - set up a target at about 25 yards. Set up the gun in a firm stand or sand bags. Remove the bolt. Look through the action and adjust the gun to center the target in the bore. Then adjust the reticle to also center on the target. Double check centers. The fire a round and adjust reticle as desired.

If you still want a boresighter, might consider the magnetic type. Personally, I am not comfortable with the metal collet type - sticking hard metal tight fitting objects into a rife bore requires caution, especially at the muzzle.