I don't currently own a 209x50 Encore ML pistol, but that will change soon, as I plan on getting another barrel in this caliber.
I used to own a T/C Custom Shop stainless 15" bbl and it was very accurate at 100 meters giving 1.250" 3-shot groups using 110 gr. of T7 (ffg) and a T/C 250 gr Shock Wave bullet. Velocity chrono'd right at 1600 fps or so.
When I get the next ML pistol barrel, I will be trying T7 in the fffg version combined with the T/C 250 gr Shock Wave bullet. The fffg version of T7 will give more velocity compared to the ffg granulation which will be beneficial in the pistol length barrel. I will also be trying some of the new Black Horn 209 powder as well.
Also, the sabot that is supplied by T/C is sized for their barrels and in my experience shoots better than the Hornady SST version, which is the exact same bullet, but the sabot supplied by Hornady is sized ~ 0.002-0.003" larger. I called and confirmed this via telephone, plus my own measurements of the sabots proved this to be the case. I had noticed that the Hornady version was harder to load and didn't shoot quite as good..... (even though the sabots are sourced from the same place, they are sized differently per Hornady....)
If you are shooting one of these ML pistol barrels and using loads of 80 grains or so, then your muzzle velocity is most likely on the low side and thus bullet expansion is gonna be compromised.
These ML pistols when loaded up to 110 grains or so should give ballistics that are slightly better than a 44 mag revolver and tread hot on the heals of a 454 Casull. Should give ~ 150 yds or so capability on whitetails assuming an accurate load is found, when using the pointed tip bullets such as the Hdy SST or the T/C Shock Wave.
Put a Burris 2x-7x scope on one (or your favorite scope) and should make a quite capable whitetail rig.
