Time To Put Down the 10mm?

[4949shooter]

They look like .45-70 rounds. 

[BEEMER!]

As deep as that bullet is seated it looks like you would run out of room for powder, especially the slow powders you would need for that load to be effective.

[Intercooler]

   The video I shot was of the 700gr. I can tell you the shorter ones (300gr range) had much more blast and pop. I wish I captured those in another video because they were hitting that big guy hard and I could feel the heat rise from the flash. The lighter weight bullets with more powder seem to have more snap to them IMO.

[The_Shadow]

Well that is where proper powder selection versus the amount of space left in the case has to reach a balance of burn rate, gas production, pressure and velocity come into play.

Hodgdon's LilGun powder provides a good balance of all of these criteria...look at these numbers.

This is posted at http://www.reloadammo.com/500sw.htm

700 GR. Lead Flat-nose GC .501 (MAXIMUM Loads)(Monster recoil)
  (Ranger Rick Bullet  http://www.lsstuff.com/ranger-rick/ )
    Lil'Gun   27.2 gr.   1,294 fps
    Lil'Gun   27.5 gr.   ~1,200 fps (max, start lower)
    Lil'Gun   27.0 gr.   1,126 fps personal, Hi=1152  Lo=1093 Spread=58.6
          damn this mule kicks, had to use gloves, both on my right hand
          to stand the recoil. Good spread & accuracy. You won't shoot many of these
           (This is 1970 foot pounds of energy)
     (Note, do not compress the powder with seating bullet - increased pressures)
    H110/W296 24.5 gr.   1,200 ~ fps (24.0 to 25.0 gr. are used)
    H110/W296 25.0 gr.   1,036 fps  Hi=1042  Lo=1022, spread=20.1  Great load from
                                      Bill Bramlett of Ballistic Supply
    H110/W296 25.4 gr.   1,067 fps  Max - bullet seated out sightly to avoid powder compression
    IMR 4759  22.2 gr.     982 fps.

[BEEMER!]

When i was loading the 500, Lil'Gun worked well along with H110 for about everything.

The trouble with the 454 was there was never enough room in the case to get enough H110 into it to maximize the load.  I used a lot of #9 for it.