Zonie,
You remind me of an incident back in the '70s when I first started this silly pastime. A good friend and I decided to both build the CVA Kentucky pistol kit; as stated above it has the same arrangement with the nose cap.
Mine went quite well but the inletting on his was poorly done. We didn't know enough then to fix it; we just assumed it was supposed to be that way. One of the problems was the barrel channel was uneven, so his barrel did not fit well. But, with the tang screw at the back and the two screws through the nose cap we managed to force it down and hold it just fine. It worked ok for a while but eventually that bit of wood under the nose cap cracked and it finally broke off, as you described happened to your friend's gun. That was too long ago to remember what loads we were using, but we tended to like making lots of noise and smoke. We cracked the stock on a CVA Colonial pistol also, probably due to a hot load.
That was about the time we figured out that it was acceptable to assume the kits, and even finished guns, weren't necessarily perfect out of the box. Ah, the naivete of youth!