Greg Barnes and I replaced three or four of these on a route in Red Rocks a few years back. Being that they are 3/8" and have "Petzl" stamped on the head, at a glance they look like good bolts... Yikes!
These are good bolts. They have more than enough thread in the sleeve (not shown) to hold a huge fall. The negative is that if you don't get them tight they don't have to loosen up much to fall out. I never had one fall out. We placed a lot of these in the 80's. Just try getting the sleeve out.
Petzl self-drive bolt with Leeper hanger - found and replaced on pitch 3. Note that the bolt did not shear off, this was its full length. Thanks to the ASCA for the replacement hardware.