Mehavey,
An acquaintance of mine has tried it, and confirmed, at least to his satisfaction, that it really is a better mouse trap. Today, taper crimps have become standard for 45 Auto die sets, so you might have to get a Redding 45 Auto Rim Profile Crimp die to do it. I bought one for the experiment, but it's one of a long list of experiments I am working through. 308 pressure v. seating depth ladder is the next one on the list, so I'm not there yet.
Oldbear1950,
Note that Alliant's maximum load for a 200-grain lead semi-wadcutter is 4.6 grains of Bullseye. So, in your shoes, I would actually start with one round at 4.2 grains of Bullseye, which is a classic 200-grain target load, then try 4.4, 4.6, 4.8, 5.0 (the classic charge for 230-grain RN), 5.2, and so on while watching for pressure signs. I note that Alliant has a 200-grain Gold Dot all the way up at 5.8 grains, but a cast bullet with lube grooves will be longer and seat deeper, which raises pressure, assuming the primer doesn't unseat the bullet faster than the powder gets burning. So what you are going to see by way of pressure is something you'll have to try out and see. I am not saying you can't get to 5.3 grains. You very probably will, as the bullet Alliant was working with was a swaged bullet that would have been softer than your cast bullet. On the other hand, it would not be lengthened by a lube groove.
Having experienced a burst case in a 1911 one time and having had to have my doctor take a brass fragment out of my cheek by slicing and removing and stitching back together, I am just recommending you err on the side of caution and not start as high as you proposed.