Im going to tell all. There is really no secret to loading Gary's .41 wildcats. I was concerned when I got my first one, a .41GNR#2, I was really lost as to how to feed the beast. I got the .41RemMag first and when I decided I needed bigger I got the .41GNR#2 in a Contender, then I got "The Green Machine". So all the heavy bullet stuff I learned on the .41GNR#2 first. When I got that .41 wildcat I had no idea of what to feed it or how much. Gary sends load data with all his wildcat rounds but I just felt that it was very conservative. Looking at the load data I saw that it, in some ways, didn't even approach the power level of the parent cartridge for the .41GNR#2 which is the .445Super.
Well I have always gone by the adage go to the person who knows. I started talking to some of the long time pistol guys. I contacted some by mail, phone and email and they almost all said what Paco Kelly told me best. The .41 as compared to the .44 (as in .41GNR) has only .019 difference in bore diameter and in some cases not even that when you see .41s at .411 or .412 and some .44s at .428-7. The difference is small. What he suggested made total sense, JUST USE THE DATA OF THE PARENT CARTRIDGE AS YOUR REFERENCE. Use standard loading procedure of starting 5% below and work up. That is all I do for thr .41GNR and .41GNR#2. I find a load in .44RemMag or .445Super for the bullet weight I want, in this case a 250g cast, then go from there. I usually load at .5g increments when working up loads and always weight every one until I get to where I want. So using that I found loads using 2400 that went from 18-23g and for 4227 from 22-24g (great powder by in .41GNR it really shines in .41GNR#2). These loads are for CONTENDERS but are safe in my Reeder 5 shooters. After I found the load range it was a simple thing to zero in on my power range of 1150-1250fps by shooting over my Bata Master. So I now load one bullet and load in .41RemMag (but I get two power levels depending on if I use the load in a Ruger or a Contender), and one bullet and 2 loads in .41GNR, and one bullet and load for .41GNR#2. So all this to say I load either 250wfngc/15g/2400 or 250wfngc/21.5g/4227 in my .41GNR to get that magic speed for me of 1196 and 1234 in "The Green Machine. That is all there is to it. I decide the bullet and load level I want. I look at the published data in all the books I have. Pick a few out, start low, work up, tweak the good loads, shoot the finished product over my Bata Master for at least 50 rounds (to be sure that the load is in fact stable), then go out and kill something with it. There is nothing in that procedure that is unusual from what Id bet 99% of the reloaders do.