Re: round balls in 1 in 66 twist
My experience with the Hornady Conicals has been nothing but good. I find them very easy to load....much easier than a PRB, as I simply dump the powder charge, put a bore button on the top of the tube, and then the Conical goes down the tube until it rest against the charge.
The Conical is much easier to push down the barrel on second, third, or fourth shots without a swabbing, (and when I do swab I use an alcohol patch).
The Conical is designed for the small "hollow" skirt to expand into the rifling of the barrel when the powder is ignited, so no blowby occurs and thus, no barrel leading.
The bore button seems to do some-what of a clean up of any real heavy residue in the barrel. I do get tighter groups using a bore button that not using one.
In any event, I'm sold on the Pa. Conical for accuracy and for better wound channels on deer.