My parents gave me a CVA Buckhorn as a Christmas present a few years ago.
Dad and I were pretty impressed with how it shot right out of the box. It came with fiber optic "iron" sights that were actually made of plastic. The hunting season before last I was walking on snow covered ice when I slipped and fell and broke the front sight clean off. I already had the 3-9x scope for it but hadn't been able to make it shoot well. It turns out the mount I had was wrong, with the correct mount it shoots well. I use 80 grains of loose 777 powder with a 250gr TC sabot which will produce 1" groups easily at 50 yards. Thats not extreme accuracy but this is a really cheap gun. The fit and finish is nice but it does have a problem.
This is the closed bolt position. The thing is that this is quite a primitive system and in this position the primer will have been struck and the gun has been fired. That means you can't transport it like this.
In the open position you can see where the primer goes and this is the real problem.
The breech plug holds the primer in the center. The primer is retained by a spring clip around the hole. The breech plug itself is tightened with a slotted screwdriver. The problem is that any time water gets anywhere near the breech plug it can go through the slots, around the primer and in the touch hole and wet the powder. The time I fell snow packed into the breech and wetted the pellets I was using at the time.
Obviously those weren't going to go off. I figured that the problem was only because snow had really packed into the breech and I wouldn't have trouble if I took basic precautions. Well last December I spent two days in the field and didn't fall down once. I did however go through some heavy country. After the first day I pulled the charge and found it soaked.
That clump toward the top of the picture is all wet. Thats a duck sauce container from my local Chinese restaurant, they're super handy for this.
To ensure I didn't have an issue the second day I packed Bore Butter into the slots the screwdriver engages. With the breech plug installed I used a toothpick to ensure all the gaps were filled. I didn't get a chance to pull the charge until recently, when I did I found all the signs of a wet charge that had dried out. This one *might* have gone off but I wouldn't bet on it.
Contrast this to last spring when I was turkey hunting, I had my percussion cap 16ga and it was raining. It rained so much it pretty much ruined whatever crappy finish there was on the stock, that stuff just melted off. I pulled the charge every day, its super easy on a shotgun, and never found any sign of water intrusion. That was real black powder instead of 777, both are fairly hydroscopic but the percussion cap covers the only point of ingress on that 16ga, unlike the CVA.
The CVA is an "inline muzzleloader" which means the primer is inline with the barrel. Its the hot thing these days, the 209 shotgun primer gives powerful ignition and when the powder is dry I really can't complain with how the gun shoots. However that accuracy is no good if the gun won't go off...
I was thinking about another in-line. The newest models are break action which gives good coverage for the primer and prevents the ingress of water but then I was thinking that my 16ga works just fine why not get another percussion gun, a Hawken would work great. I'm thinking .54 cal, it'd be fun to play with a big bore gun for a change and "The Ancient Ones of Maine" gun show is coming at the end of the month...