I took that fixed-up Zouave to the range today, and nothing blew up! Well, the hammer did pop back to half-cock with one shot, which sent little burning thingies out onto my hands . . . but meh, that's the cost of doing business, right?!
I put about 20 minie balls through it, both 475- and 510-grain versions. I tried both 50 and 60 grain charges of FFg powder.
It shot just about like most of my black powder guns. Here's a typical target at 50 yards.
(Ignore the little wussy holes.)
Recoil didn't seem too bad . . . but as I was driving home, i felt my shoulder start to ache.