Do not laugh, but in a previous life (actually on another continent) I culled donkeys in conservation areas where they could cross-breed hybrids with the endangered mountain zebra. From experience I can confirm that a good quality 240gr soft nosed bullet from a 6.5 - 7.5" revolver will shoot sideways through the shouldes of an average sized donkey.
In Canada I have chronographed velocity in six different 44 Mag firearms, and I list velocities recorded in three, my homemade (and legally registered!!!) 4.2" Custom S&W 629-6, my 7.5" Ruger Super Redhawk and finally, my 20" Marlin 1894:
240gr Win JSP factory load (very hot!!!) = 1231ft/s, 1414ft/s and 1758ft/s (Yes, the rifle really gives 300ft/s more)
300gr Frontier CMJ using 95% max 2400 powder = 1083ft/s, 1202ft/s and 1418ft/s. In this load with the heavy bullet, using H110 / Win 296 should give about 100-150ft/s more in the rifle.
However, do not use round nose bullets as mentioned in post #10 in a Marlin Lever rifle. Only use flat nosed or bullets made for lever rifles.
Best loads in my opinion (I have not seen any ConBon in Canada) is the cheap`` 240gr Win JSP mentioned above, the expensive Win Gold with 250gr Partition bullet, or best, load the 270gr Switt A-Frame, using the slower H110. In my Marlin 1894 the 300gr bullets do not feed reliably unless deeply seated in the case, as Speer prescribes in their Number 14 Manual. However, this reduces case capacity and I believe the 270 Swift A-Frame to be the best for a rifle. Would love to try the Ruger 44/77 bolt rifle.
At point blank range, the 44 Mag has more stopping power than a 30-06 with 180gr bullet, not only on paper but also real life (RSA = Reallife Shooting Analysis).
Regarding reloading data for bullets over 300gr, the Hodgon 2011 Annual Manual lists 3 bullet types (325-355gr) on page 164, and the Second Ed. Lee reloading manual lists 4 bullets (320-355gr).