In 2009 I developed the 500 MDM, which is a 2.8 inch RUM case, uses a .500 caliber bullet. Not .510, but .500............
The rifles are Winchester M70 RUM actions with 20 inch barrels as standard. These rifles require a Accurate Innovations Stock with the full length aluminum chassis. Depending on the wood they come in at 8.25 to 8.75 lbs.
I have done extensive Pressure data, load data and bullet designs around all the .500s I developed.
In 2009 I had a really nice 550 gr Lehigh SSK designed solid. With several different powders I was able to easily hit 2175 to 2210 fps with it. However, I never used it in the field, there was an identical bullet 510 gr that I used on a couple of elephants and several buffalo getting over 8 ft of penetration in elephant, 550 was just not needed....... and this was very early on.
By 2011 we had developed the Cutting Edge #13 Solids for the .500s, and being a solid fan, I had .500 caliber solids coming out my ears..... 375 gr for 50 Super Short, 375 and 405 Lever Solids for my 50 B&M Alaskan guns, 450, 475, 500, 525, and 550 gr CEB #13 Solids for the larger bolt gun calibers 50 B&M, 500 B&M and 500 MDM........ I used mostly the 500 gr version on a lot of buffalo and a few elephants. The 500 MDM would run the 500 Solid to 2350-2400 fps and it would drive end to end on elephant and buffalo of course...... And knock the crap out of them as well.......
As for the 550 gr CEB #13 I had a load of 90/H-4895 that hit 2262 fps at 61800 PSI. And many other loads that would run 2137 fps 52000 PSI to 2216 fps at 58000 PSI......
But a 550 is just not needed or required for any reason...........
My personal favorite solid is the 525 gr CEB #13 in .500, but only if I was using it exclusively for elephant, 95/H-4895 runs the 525 gr #13 at 2361 fps at 63000 PSI, 94/H-4895 2338 fps at 61000 PSI, and a nice easy load 92/H-4895 at 2289 fps 57000 PSI....... this bullet drives extremely deep and hits hard as hell up front.......... End to end Elephant and bust bone in between.......
This is my English Stocked 500 MDM used in Africa many trips buffalo and elephant..........
This is my Myrtle Stocked 500 MDM with the barrel cut back to 19 inches. It was the first 500 MDM built in 2009 with a 20 inch barrel, used exclusively in Australia for 50+ buffalo............
My friend Sam has several 500 NE double guns, and we did a big study on 500 NE. Knowing what we knew about the CEB #13 Solids and heavy weights just not needed, he had Dan at CEB make a 510 gr .510 caliber #13 Solid, and matching 475 gr CEB Raptor for his 500 NE guns. We were able to run the 500 NE and 510 solid to 2306 fps at 43400 PSI and the 475 Raptor with the same load of RL 15 to 2312 fps at 39000 PSI...... This combination has been used in 500 NE since 2012 with incredible success on a lot of buffalo and a lot of elephant.
With todays bullet tech heavy weights are no longer required to accomplish the penetration needed.
I had another pet project a few years ago, 500 B&M. This is also a RUM case, but cut to 2.5 inches and uses the same Winchester M70 RUM action and 18 inch barrel. There were two of these built, I have both and never really turned them loose. These are extremely handy rifles at 18 inches.
This cartridge is quite capable as well, and it can run the CEB Raptors with Talon Tips added through the magazine, which was one of the reasons I designed it at 2.5 inches. You can see the Talon Tip load above in the cartridge photos.......
If you want heavy weight, the 500 B&M runs the 525 CEB Solid at 2185 fps with 84/IMR 8208 at 58000 PSI. But again, this would be for elephant only............ I actually used the lighter 450 gr Solids at 2400 fps with 96/X-Terminator for 57000 PSI for buffalo after taking a hit with the 410 Raptors at 2520 fps..... massive destruction........ I also have a Myrtle Stocked 500 B&M........
It is a joint effort, cartridge, rifle and remember, the Bullet Does all the Heavy Lifting, choose the bullet wisely, and the cartridge/rifle can perform as designed.
