Here is my "history" with the PA conicals.
My first frontstuffer was a T/C White Mountain Carbine with either a 1 in 32 or 1 in 38 twist, I don't remember for sure. Either way, it's a very fast twist designed for conicals and sabots. The barrel is only 21", which is pretty short! It will drive tacks with the T/C Maxiballs and Maxihunters. However, not being rich, (The Maxi's are pricey), I somehow stumbled onto the Hornady PA Conicals. They sell around $7.00 for a box of 50, which is very reasonable.
My first year of muzzleloader deer hunting, I had an unlucky doe stand almost broadside to me, quartering only slightly away, about 60 or 65 yards off. I nailed her in the front shoulder and it went through the far side leg bone on the way out and kept going. This with only 75 grains of Goex 2F. Complete penetration, with an awesome hole on the way out. Stevie Wonder, Ronnie Milsapp, and the beloved, late Ray Charles could have followed that blood trail for the 60 or 70 yard dash that she made!
My second rifle was a T/C New Englander, with a 1 in 48 twist. It also shoots the PA Conicals very well. I haven't worked with it as much though.
I don't know if you've ever seen one of these PA conicals yet? If you haven't, I think there is a picture of them on the Hornady website. They are a very short, (in length) conical. Maybe that's why they are supposed to work in a slow twist?
They weigh in at 240 grains for the 50 caliber, which is a little more than a roundball. For the one and only deer that I shot with one of these conicals, the performance was amazing.
The only weakness in the design is that I think that the "skirt" of the conical is thin enough that it seems to be a little fragile if driven too fast. If I shoot them above 80 grains of Goex 2F, the accuracy falls off. My theory is that the skirt deforms.
Again, the performance with 75 grains Goex 2F was awesome,... it's all you'd need for Whitetail Deer.
Also, remember that my twists, especially the White Mountain Carbine are way faster than yours, so a 1 in 66 may not be spinning as fast and the centrifugal force may not be so strong and the skirt may not deform... I don't know.
I will only have one muzzleloader myself this coming season. I'm gonna give my White Mountain to a young fellow and I'm gonna loan out my New Englander to a beginner. All I'll have will be my Early Lancaster with a.... you guessed it, roundball twist barrel! It's a Green Mountain 50 caliber, and I think they make them 1 in 70.
I read on the Hornady website the other day that the PA Conical is actually designed for a 1:66 twist barrel... I honestly hadn't noticed that interesting fact before. I just used them because they were cheap and they shot accurately for me.
Anyway, I'll probably just shoot patched roundball in my Early Lancaster this year, but if you can get a hold of a box PA Conicals, maybe you can work with them and let the rest of us know what you learn about them.
Oh, one other interesting thing that I think I've noticed is that with PA and other conicals, the first shot of the day with a clean barrel seems to impact a couple of inches higher than the later shots from a fouled barrel. If you do end up using PA or other conicals for hunting, pay attention to this phenomenon. Maybe it's just in my rifles, but be sure to keep your eye out for this if it does happen for you too.
Hunt and Shoot Safe,
Ironsights Jerry
