Paper patch accuracy

I might just try a little over 500 grainers. Just to see what happens.

How long did it take you to shoot that group? You might not think wind was an issue but if it changed a couple of mph or switched on you a little it could. Where was the wind from? 9 and 3 o’clock are full value winds with the largest impact on left and rights. 12 and 6 o’clock that are shifting can be a real bugger and are hard to judge. Do you shoot with a wind flag? If not you can do it on the cheap. Simple stake with a light ribbon. Put one at the line Half way and at target. The wind closet to you will have the most impact on the bullet.

What about light change? This also will impact your shot placement.

I think the slight change of conditions along with the amount of time it takes you to shoot and perhaps you as a shooter can account for the group size

Do you have a buddy close by with a target rifle that you can swap guns and see how each other does with a different rifle compared to what the rifle normally does? It could even be a 22 at 100 yards



Fleener

Weight doesn't have much to do with it. It's bullet length. .442 diameter at 540 grains is going to be on the extreme end of length an 18 twist barrel is going shoot stable consistently, and especially if there's any cross winds. Small bullet diameter and thick paper seldom go together when a person is looking for pure accuracy.

Fleener, I really don't think wind was very much of a factor. One to two miles an hour from dead behind me and I was shooting faster this time. If a person doesn't see much of a change after a initial cleaning shot, then it must have been my shooting because the second group was a whole bunch better. Maybe I will try cleaning better between shots. Then also try cleaning less between shots.
Ranch, the length of the bullet is 1.375" long which is right on for most 18 twist barrels.

Ok, so with that length it would seem to be more of a round nosed bullet.
Have you read the chapter in Ned Roberts Muzzleloading caprock rifle book about the paper patching and shooting bullets.
One thing you might consider to is playing with the powder charge, sometimes 2 or 3 grains can make a pretty big difference in group size.
You also might want to think about a simple wind indicator at your firing point.Even at 200 yards a simple wind shift can raise havoc.

I don’t have my wind charts to tell you what a 1 mph wind will do to you at 200 yards (on a cruise ship) with me but put a couple wind indicators out. One on the line one half way. Keep an eye on them. See what happens. Do you watch mirage? Even at 200 if you want to shoot a great group you need to do this. Or just hope you get lucky

Fleener

A fluttering tail wind can really give you some fits with the vertical, and makes the mirage a bunch harder to read.