Awesome shorty!!
I like a low power variable (as above) for it's versatility. Coupled with an illuminated reticle with single center dot, it can work like a red dot sight up close at 1X and easily do 250yds at 4X.
Depending on your budget, I'd look at 1-4s by Primary Arms, Vortex Crossfire II and Hawkes in the Vantage and Endeavor lines. Going up in price, the Leupold VX-R in 1.25-4 (Firedot Duplex) is a great choice.
I have and use all of the above on rifles chambered in .44mag, .45C, 9.3x62, 9.3x74R, 444, 45-70 and .450.