OK. Let's dispense with the usual mantras that there is no such thing as a brush busting bullet. I agree, all bullets will deflect, so if you're figuring on posting your wisdom on this thread please spare us the static noise.
I believe that it is possible that there are some bullets that won't deflect as badly as others. For those who believe as I do, I would like to see some discussion, links, articles, experiments, and other information pertaining to factors OTHER THAN bullet weight.
*Does rotational speed have an effect? Rotational speed as derived from multiplying twist rate and velocity. I.e. I have a Lyman Great Plains rifle and pistol of the same caliber. Both shoot a .530 ball, but the rifle has a twist of 1:60" wherease the pistol has a 1:30" twist. Shooting over a chronograph reveals that the pistol launches the roundballs at roughly half the velocity of the rifle. Thus, twice the rifling pitch at half the velocity yields the same rate of spin. I have seen some evidence that faster spinning makes for a bullet that is more sensitive to deflection.
*Does bullet shape have an effect on brush deflection? This is related to bullet spin in that bullet shape (and length) dictates the amount of speed required to stabilize it. Could it be that those bullets that require a lot of spin to stabilize are also easily destabilized? What bullet shapes require the least amount of spin?
*Does bullet material have an effect? Roundnose bullets often have more lead exposed. Does the softness of the lead cause bullets to deform easily which would destabilize?
I have a fair bit of experience shooting deer with roundballs fired from muzzleloaders. I can say that at first blush the roundball seems to be a miserable brush buster, perhaps worse than others. However, of all the bullet designs they seem to be the ones that require the least amount of spin to stablize. So that would seem to shoot holes in the theory that less spin and an inherently stable shape make for a good brush buster. UNLESS the poor brush-busting performance I've witnessed is entirely due to the fact that roundballs are made of soft lead, soft as possible which would mean that they deform too easily when hitting a twig.
I'm wondering if it would be worthwhile to harden up the roundball alloy.
Your thoughts?