I have punched myself in the mouth more times than I care to remember. However, each time I did it I was using the old style Stanislowski Back Tension Releases. Since I know how good it feels, I now use a hook type release with my loop instead of a caliper style. I have seen several people do just what you did using caliper realeases with loops. It also makes you pretty cautious as you draw back, you know what I mean.