I have a carbine length 44 Mag barrel I am thinking about having rechambered to 445 Supermag. What kind of performance increase can I expect? Also will my RCBS 44SPL/44Mag dies work for this caliber? I know several are going to say go to the 444 Marlin. But if I can use the dies I have on the supermag I don't have to buy new dies. Also I know I can still shoot 44 Mag ammo in the supermag. I don't think you can in the 444. What are your opinions?

Thanks,

John

Most 44 mag dies will work to load the SuperMag, I have seen a set of RCBS that would not work, everything else has. You could try a 445 case in your dies, if the die is cut deep enough for the 445 case it will work, if not, you will know it immediately. Rechambering the barrel will give enough velocity increase to make it worthwhile, how much increase depends on the barrel and the bullet weight. Yes you can still shoot 44 mag ammo in the 445 chamber. You cannot shoot 44 mag in a 444 marlin.

My Sierra pistol manual shows data for the .44 mag and .445 SuperMag in 14" T/C barrels. The 240 gr bullet gains 350 fps, while the 300 gr bullet gains 450 fps. You will probably get more of a gain in a carbine length barrel. Not too shabby.

I do have a .445 SM in a 12" T/C. Yes, my .44 mag RCBS carbide's work fine for sizing the .445 SM. Even with a muzzle-tamer, this is about all I can handle in a SSP - in fact, I don't really shoot this one much any more.

I have a 10" pistol barrel, and a 16-1/2" carbine barrel for my T/C Contender in this caliber. I like it and think there is definitely a noticeable increase in performance over a .44 mag. Enough to make almost any .44 mag bullet 240 grains and under fail on impact. I was blowing Sierra 220 grain "FPJ" bullets apart in one water filled milk jug with it, and they're pretty tough.

Recoil is pretty good, but being able to use regular .44 mags, as well as .44 specials, takes the edge off a little, though none zeroed the same as full power loads for me. It all depends on the bullet weight, but unless you use the heavier bullets, most will overexpand.