Ok, so it would seem the 45AR rim is too thick for some revolvers headspaced for 45LC. However, there are 2 work arounds I can think of offhand. You could cut down 45LC cases to 45AR length, But then you'd have to ream the inside of the case because while the 45LC case is straight walled on the outside, it is tapered on the inside. The other, simpler method is to simply download the 45LC reload to 45AR velocities with an appropriate 45ACP projectile. Frankly, if you're insistent on firing 45ACP style rounds, either ACP or AR, then it would seem the prudent thing would be to use ACP with moon clips.
Which brings me to what I don't care for in Governor style handguns. In order to accommodate the 410 shotshell, the cylinder must be long. The bore of the cylinder must be machined out to accommodate the entire length of the shot shell. For the 410 round, that's great. But, the rifled barrel acting on a shot shell designed for a smooth bore, not so good. I suspect that the newer shot shells designed for revolvers perform such that the shot never touches the rifling. For more traditional handgun rounds such as the 45LC, 45ACP, or 45AR that leaves quite a lot of free bore inside the cylinder where nothing is acting on the projectile to keep it straight to enter the forcing cone. If, the projectile does happen to rub some of the free bore, then the projectile may be upset causing it enter the forcing cone slightly upset (not straight). To say nothing of gasses bleeding off from the chamber while the projectile is in free bore.
I would think a more ideal situation would be to take 45-70 cases, which I believe matches the rim diameter thickness and width as 45LC. In addition, I believe the base diameter also matches. Cut down the 45-70 cases to a length much closer to 410 shot shell cases. You'd prolly still have to ream the case mouth to accommodate whichever 45cal bullet you prefer, then load with powder appropriate to the projectile weight and velocities you're trying to achieve. This would place the unfired projectile much closer to the forcing cone and would assure that the projectile would be less likely to be upset before entering the forcing cone. Naturally, this is just a mental exercise for me and many aspects and assumptions of mine may be wrong, but I thought I'd throw it out there. In so far as reloading data is concerned, you're on your own. I have no idea where you'd start with powder or projectile. I do know that in some instances, too little powder for case capacity could be explosive.
