Philthy1: They seem pretty effective. I have a refurb sniper with two cross-bolts in the wrist area and have shot a lot of rounds through it with no problem. On the other jand, as Horilka indicated, the repro mounts may damage your notch. The cross pin seems to be too high and can damage the rear of the notch. I'm thinking of putting a thin brass or copper shim in the notch to stop the damage.
milsurpo