With all of the new “Magnum” muzzle loaders that are out their now, and all touting to handle loads up to 150 grains, at what point do you say uncle? My favorite front stuffer is a White model super 91 that I have up dated with 97 ramrod holder and fiber line sights. This muzzy just loves to digest the 460 grain No Excuse conical bullets.
A few years back I decided to give Knight a try and ordered a 26 inch stainless steel “Bighorn” in 50 caliber. My hunting buddy had bought one and was getting some phenomenal result with his muzzy using sabots and 260 grain Hornaday pistol bullets. I have never had good luck with sabot and pistol bullets but I decided to give it a try.
His best load was shooting a respectable group with 120 grains of black powder. When I loaded mine up with the same load, I had horrible results. My target of choice is a pizza box with a three inch orange dot at sixty yards. After several shots I could see that this load was going no where fast and tried several different load and bullet combinations. The best grouping was with a Cape Buffalo 480 grain & sabot and 90 grains of black powder fff. I tried some “Powerbelts” and had marginal results with these bullets also. It just was not happening for me at those increased powder charges.
On another shooting session in the snow we started shooting our muzzies with our favorite loads, and I noticed that my buddies Knight “Bighorn” was leaving smoldering unburned powder all over the snow.... I asked him what was up with that and he told me that he had changed nothing in his regime. As I would shoot with my loads, we would find nothing on the snow, however my loads were less than 100 grains. From that shooting session we learned that black powder and substitutes can and do reach a point of diminishing returns. We found that on average that anything over 110 grains of powder was leaving un burned powder on the snow. We gained about 5 grains with fff powders over other sizes but it was not significant to make a big difference to us.
For awhile we thought that pellets where the answer to increased charges, because we never seen the unburned powder residual on the snow. On one cold shoot we walked up to the target and found a 1/4 unburnt Pyrodex pellet was stuck in the bottom part of the box. From that point on I am convinced that somewhere around 110 to 115 grains of powder are the magic numbers to say that you are just blowing smoke out the tailpipe.
Disclaimers to my observations are that in no way can I tell you that our test were scientifically controlled and that we have not tested at all temperatures, with all powders and substitutes or ignition systems and barrel lengths. With that said I will still say that in my humble opinion, in the vast majority of muzzle loaders, if you are using more than 115 grains of powder or equivalents, you are just producing nothing more than extra smoke.....