I do some pretty extensive shooting with muzzleloading firearms, and have been doing so for a good 20 years. I'm very picky about the guns I shoot, how they're loaded, and the factors that influence my accuracy. My sighting in and tweaking are done on a bench, my target shooting and competitions are done off-hand (standing, with no rest). I shoot only flintlock muzzleloaders, which are also "traditionally" styled. I easily fire 300-400 well aimed shots per year with these weapons. I also shoot 22-250's, .270's, .22's (LR, Shorts, CB's, and Magnums), 38's, and a 12 gauge using both shot and slugs.
I can throw some information in to answer or at least give light to the slower heavier projectile question which originally opened this thread.
Regardless of propellent type used, the larger sized projectiles do not lose much, if anything, due to their size- at least as far as accuracy potential is concerned. The size really isn't the issue. Barrel quailty/straightness, sights, aiming ability, weapon soundness, and consistancy of loading affect accuracy much more.
The big projectiles slow down faster, and as a result follow a more "arched" trajectory. They are more prone to wind-drift, a factor not in play in AH. When a bullet is stabilized by the rifling, it is spinning along the longitudinal axis. It slows down in forward flight, but this spinning does not slow down nearly as fast. As long as it spins enough, it is stabilized. Its RPM will slow down enough to lose stability well past the point where the projectile has lost enough forward speed to be effective. So it will lose power well before it loses its potential to fly straight.
Of course, as it slows in forward movement it also becomes more succeptable to wind-drift, etc. And a spinning projectile will "walk" to the side a bit, which seems more pronounced as it slows.
It's interesting to note that a larger diameter projectile needs less spin to stabilize than a smaller diameter projectile. The ratio of length to diameter matters tons, too. My .54 caliber roundball needs only a 1 in 70 inch twist to stabilize, where my .50 caliber roundball needs about 1 in 56. Conical projectiles need more rapid twist to be stabilized. I'm not actually going to get up to check, but I believe my .270 needs about 1 in 17 inches, and my 22-250 needs 1 in 10 or so. The greater the ratio of length/diameter, the faster the twist. Also realize that the amount of inches traveled during one full rotation isn't the real important thing, the RPM is. Firing a projectile at a faster speed also increases the RPM. A bullet traveling a given distance spins the same number of revolutions regardless of its speed. You can make it spin faster/slower though by increasing or decreasing its forward speed (how much powder, more or less).
Sights and shooting/aiming ability are more important, given an adequate firearm. My .54 flintlock with its 1 in 70 twist will fire shots into a 3 inch group at 100 yards all day, even with open sights. I know lots of folks that can't do that with a scoped 30-06 or .270. My scoped .270 will shoot 2 inch groups at 200 yards. So would my .54 if there was no wind and I attached a scope. My 22-250 shoots accurately enough to shoot dimes at 200 yds. Why? Because it has less recoil to throw off my aim, the bullets are cheaper, so I shoot more (practice), and it is more enjoyable to shoot with the lower recoil.
Larger projectiles are accurate. They need even less spin to be stabilized, because they are generally shorter. They don't usually need the extra length because at the higher diameter they are already heavy enough. Heck, my .75 Brown Bess will shoot 4 inch groups at 75 yards, and has no rifling, a horribly slow lock-time (try aiming with a fireball a few inches from your eye), and a very primitive stock configuration. It's muzzle velocity is only about 800 FPS, compared to my .54 rifle at 1800 FPS, my .270 at 3000 FPS, and my 22-250 at about 4000 FPS.
With the slower velocity, a stationary target is easiest to hit. So flying straight away from one is bad.
Obviously more factors play in here, but it would be best to read a book on ballistics that to explain them all here...
MtnMan
