"Prosser,
I've loaded and fired 360gr bullets in my FA at what loading guide says should be around 1350-1400fps and they are on the energetic side. Although manageable, I can just imagine how much "fun" they would be at 1550fps. By fun I mean unpleasant and generally nasty to hang on to, much less try to focus on good marksmanship while knowing the revolver will do everything it can to hit you in the face as a reward for touching the round off.
At the power range I am loading them in the 360gr bullet should probably still flatten anything I care to shoot at on this continent, so my motivation level to go any higher is pretty low. I was surprised that the bullet gives good accuracy, even though FA states that the twist rate for their .452" barrels are really optimized for 240-335gr bullets. I noticed improved accuracy with these as velocities increased, was that also your experience at 1550fps?"
I got 12 rounds of Seyfried buffalo rounds sent to me by John Linebaugh.
I found that at that level of recoil, the grips had to be custom tailored to my hands, though at the time I didn't know this. Accurate? An elephant would have been safe with those loads at 7 yards, with the small SA grips on my Seville. I never have shot anywhere near what Seyfried is capable of.
The Hawaii pig guys settled on 1350 fps, with a 325 grain bullet. Shot a lot of these, and, never did figure out I needed custom grips. Jack Huntington finally just made me a set of grips, and it made all the difference in the world on the seville.
When I bought the .500 Max and .475 FA 83, they had grips for small hands.
At that level of recoil I was lucky to hit the backstop, much less a target, with the little grips the guns had on them. Here is a before picture of the .475 and .500:
Problem is the grips on the guns are REALLY nice. Micarta on the FA, Buffalo Horn on the .500
I had them changed to grips sized for my hands:
And they are as easy to shoot as the Seville was, except for the .500 MAX.
525 grain bullets over 1350 fps are a whole other ball game.
To tie this to the thread reasoning:
Both calibers really require custom grips, fitted to you hand size for anyone to evaulate how accurate they are.
To answer your original question:
Logically the fuller the case, the more consistent combustion, and velocity is going to be, and, that means accuracy. That is one problem with loading for low recoil, at the bottom of the pressure scale. With a big case, it's better to have it 95% full. The lower the number, the more the velocity variation.
I can't speak to .454 or heavy Colt loads in an FA, since I've never had a FA 83 that wasn't converted to another caliber. The original Casull loads were for lighter bullets.
The Sevilles by Linebaugh were designed to shoot heavier bullets. At the time my gun was VERY accurate, but, I never shot enough 360's to speculate on twist. My gun shot heavy bullets VERY well. I do remember he mentioned he had the right twist for the caliber, and his guns would consistently shoot into 2-3 inches at 100 yards, with a variety of bullets.
I think he went over that in his letters to me, but I'm not up for going back and looking right now.
Jack Huntington pointed out to me that big bullets tend to smooth out a lot of the accuracy problems in 5 guns by just being long. They tend to get ducks in a row, and heavy for caliber bullets tend to be more accurate then
light for caliber bullets, and, if the gun has an accuracy flaw, the heavier bullets tend to show it less then light bullets.
The bigger the case, the more recoil you are going to get. That is the trade off with the .44 and .45. When you really get down to it, a .44 Special
is probably the .308 of big handgun rounds.