I had an opportunity to get out and sight in my handguns, which was quite important due to the fact that gun season opens in the morning. I know, I know, I'm a procrastinator, but hey, I got it done, right?
Anyway, I took out the two handguns I'd like to attempt to use this year: my T/C Encore with a 15" MGM 460 S&W barrel, and a 7.5" barreled Ruger Super Redhawk 44 Magnum. Having acquired two boxes of the brand new Hornady Handgun Hunter line of ammo for each caliber, I decided to go through a whole box to get a good reading on their velocity and accuracy.
Long story short:
460 S&W - Average velocity 2,493 fps, 18 fps standard deviation. This was a modestly accurate load, capable of sub 1.5 MOA 3-shot groups.
44 Magnum - Average velocity 1,488 fps, 21 fps standard deviation. I didn't exactly shoot for groups, being an open sight gun, but I managed to dial it in at 20 and 30 yards.
Both loads were a bit more mildly recoiling than comparable loads. The 460 in particular will shoot the same weight 200 grain FTX factory loads to ~2,700 fps. This isn't too surprising if you think about it. Being solid copper bullets, the Monoflex bullets probably take up a lot more powder capacity than their lead counterparts. Still, it'll be interesting to see if I couldn't improve on their accuracy and velocity once the bullets become available as components. I imagine seating the bullet out further and pushing it with a healthy charge of Accurate No. 9 would be a notable improvement.