I'm not so much interested in which cartridge "out-performs" another so much as I'm interested in ".44/45 caliber factory" cartridges that are ballistically "equivalent" to each other when fired from a carbine/rifle length barrel. I'm of the opinion at this point in time that rifles like the Ruger Model 77/44 (or lever-action rifles so chambered) are fairly unique in their potentials and capabilities in terms of other factory loaded, .44/.45 caliber firearms (the .41 Magnum might come close if it was ever chambered in a rifle). I'm also curious about jmorris's thought concerning the .460 Rowland.
I'm still a bit confused on what you're looking for. And perhaps why you're looking for such information.
On the surface it seems pretty easy. Since the commonly used bullet weights for both calibers share some common weights it comes down to both shooting at the same velocity for such situations. The common .44Mag load with a 240gn bullet is close enough to the commonly used .45Colt 250gn bullet that if both are shot at the same muzzle velocity then both will have the same hitting power. From there you get down to how close a match does it need to be. Some will say that the 10/250=4% difference counts for something.
Some will say that the marginally better BC values for the smaller diameter .429 bullet counts for something. Yet others will go on about the shapes and how much the meplate area differences count for something in terms of hunting take down DRT results. And that will likely result in a discussion on how the standard method of measuring ft-lbs of kinetic energy relates/does not relate (pick a side?
) to real world hunting results. It all becomes fairly confusing at that point.
So the comparison comes down to how picky you want to be. Are you looking for casual real world matchups that are within around 10 to 15% of being equal or are you looking for <5% near laboratory match ups?
Either way a quick look at the rifle section data from my Lyman's 49th edition shows that if you want to get anywhere near close to .44Mag that you MUST move into the "Ruger Only" data for .45Colt. Otherwise the .44Mag is a clear winner by any standard.
Moving on to the Ruger large frame, TC Contender and Encore only section we see some overlapping and area for matching things up. But even looking at the Ruger, T/C and Freedom Arms listings on the Hodgdon reloading data web site I still don't see the .45Colt matching the .44Mag.
To get numbers where .45Colt matches or beats the .44Mag data we need to move over to some of the ammo examples found on the Buffalo Bore website. At that point I see some handgun loads listed that exceed the RIFLE performance found in the reloading data for .44Mag. How they are doing this when the reloading data does not support this is obviously a trade secret. Duplex loads perhaps? Specialty powder blends?
I know that there are other boutique ammo suppliers as well but I picked the BB source simply as one example.
I know that I haven't, and can't supply you with specific factory ammo examples. But it seems to me that if you're talking about finding "close enough" match ups as opposed to scientifically "exact" match ups that you'll need to look at the specialty higher pressure .45Colt ammo suppliers to match up to the regular .44Mag.
To get closer than "close enough" I'm thinking that you would need to find someone that has tested the ammo examples over a chronograph. And even then they obviously can't use the same rifle. So barrel length differences and bullet to bore fit differences will tend to mask the small differences. If we look around at data it doesn't take long to realize that the condition of different barrels gives a 2 to 5% muzzle velocity difference from the same ammo shot from various rifles. So I would suggest that a 10 to 15% "close enough match up is about as good as you will get. Actual 0% difference matchups could be due simply to a 5% difference in the ammo performance being masked by an offsetting 5% difference in bore friction.
