The math says the .309" bullets should tumble out of this .323" bore, but the soft lead and large base cavity of the 98 grain Lapua HBWCs I used managed to stabilize nicely from this ridiculously long barrel. The holes in the target showed no signs of yawing at 15 yards (probably closer to 13 yards, considering the actual distance to the muzzle.) The group would have been smaller if I hadn't kept losing the front sight in the large black target -- these days I need more contrast with my eyesight. Probably still good enough for ground squirrels. I found two issues with my new adapters, neither critical. The rim diameter was a tad undersize, so I found it necessary to hold adapter against the extractor during insertion. The fumbling in the video was me forgetting about this. Also, since the adapter is steel, it can't expand to fully obturate the breech. That means there's a whiff of gas from the breech with each shot, comparable to the blow-by from a revolver. You can see it in my short video. Not a big deal with proper eye protection, especially if you are accustomed to shooting muzzleloaders.