Fixed barrels work fine, and have worked fine for decades. I know of several people who used Ruger mk1 pistols for contact shots on hogs to knock them out for slaughter. Get them in the chute, bang them, hang them, cut them. If done quickly they were still stunned when the knife hit their neck. That was standard process for my dads uncle, and same process for a few other folks I have heard tell stories of old school slaughter days. Always contact shots to the forehead (then a second one behind the ear when the hog wasn’t trying to kill them with its tusks)
that’s a pistol with an internal action mechanism. Some pistols have rearward slide mechanisms. Some have a traditional external slide mechanisms that cover the barrel. So long as the slide doesn’t move it wouldn’t be an issue.
Hi-point is a more traditional slide type pistol with a fixed barrel. There are plenty videos where people do absolutely horrendous things to those guns and they just keep working. I’m relatively sure that Demolition Ranch had a video on the hi-point that started with contact shots and then went to blocked barrels, bent barrels, and progressed until they finally successfully broke the gun… but I don’t remember what it took to break it.