Colorado Muzzleloader Projectile Conundrum

[brassell31]

Several years ago Colorado changed when one can use a roundball or conical for big game hunting. 40-50 caliber roundballs in the past were acceptable for deer and Pronghorn. My sidehammer caplock shoots a .433 roundball weighing about 120 grs. Worked perfectly on a forkhorn Muley buck 6 years or so back. The shot was close to 90 yards and it double lunged him and passed through the body and out. He ran 120 yards and died. Now I have to uses a projectile that weighs 170 grains minimum for that caliber, which means a conical. The twist on said rifle is close to 1/60. If I can find a conical small enough to fit the bore, I'm wondering if that slow twist will stabilize a conical? Anybody have any experience with this or advice? The bore groove diameter is .448" (Miroku barrel).
Colorado also allows that .50 or better must be used for elk, and has to be a conical up to .54 cal, where a roundball is allowable. Sabots are not allowable in Colorado. 2 years ago I shot a similar sized Muley at the same distance with my .54 flintlock, it double lunged him and actually left a groove on the back of his heart. That ball passed through also. He ran over 200 yards before he piled up. Now I could hunt with the .54 all the time to solve the problem, but it weighs 4 more pounds than the .44, and playing the old age card these days, the .54 is just to heavy unless I'm hunting elk. Any Ideas for the .44?

 

[Treestalker]

A conical in a slow twist barrel can sometimes do ok with a smaller powder charge - if it is not pushed too fast; reference the slow twist Civil War muskets firing Minnie bullets. Only thing is they used a really shallow groove. If you can find a combo that works in your gun, you may do ok with it ; every gun is different. I'd try a Lee REAL bullet with a start of about 50-60 gr 3f.

 

[Frontier's]

you cant use a .44cal for elk. Must be 50cal shooting conical or a 54cal shooting patched round ball.
https://buckskinsbp.blogspot.com/2020/04/hunting-colorado-choosing-muzzleloader.html

 

[bang]

Curious. Would a conical in -010 shoot good patched .015? Patched would insure gas seal and catch riflings.

 

[Frontier's]

Conicals do not use patches.