I have a few big bore semi guns. I confess they are the least interesting to me of any of the B&M cartridges. I had the designs for a long time, and the rifles in which to put them on. But these were way on the back burner for me. Finally JD called up and wanted to do the the B&M SA--(Semi Auto), so we went to work on the first two, which are both on AR 10 Platforms.
Back in the day, DPMS made some rifles chambered in 300 RSAUM. The B&M case is a 1.95-2 inch RUM case, and these would be easy conversions to big bore. No bolt face work at all, and magazines already designed for the fatter cases. I had a couple of these, so sent those up to JD at SSK.
The first gun was a .500 caliber rifle, we call it the 50 B&M SA. The second was a 458 version of the same case, the 458 B&M SA. In my data here I show the first loads went down range in January of 2010. After going through the basics of getting them to work, which was really easy, some magazine tweaking by Brian at SSK solved all issues. Both rifles had 18 inch barrels. Both are heavy as hell at 10 lbs.
After getting basic data and making sure they worked, I put them to the side and did not mess with them at all for several years. I did not have much interest in them, and was heavy hunting during those years, and semi just had no place in my agenda at all. SSK built several rifles over the years, but I turned everything over to JD and SSK with these, I didn't want anything to do with them. They served no real purpose for me, other than just something to play around with.
Then in 2014 I more or less officially retired from Hunting. I got bored. So looking at these things in the racks, I decided to just find out what potential they had. I went to work on some serious load data for these things.
What I found with the 50 B&M SA;
300 gr Hornday 2400 fps
335 Raptors 2300 fps
350s 2200-2250 fps
375s to 2150 fps
400s to 2050 fps
I personally like the 458 B&M SA better;
The 250 Socom Raptor by CEB is a very serious .458 caliber bullet, and it is made for things just like this, along with the various bolt gun cartridges as well. And the main load for this gun
250 Socom Raptor 2670 fps
300 North Fork 2436 fps
300 Barnes TSX 2421 fps
325 Safari Solids 2327 fps
325 Hornady Flex 2350 fps
Various 350s from2150 to 2250 fps.
Once I got that done, lost interest again.... HEH......... Loaded up a few hundred of these in case there was a Zombie Apocalypse, and put them back in the rack again..........Where they remain today.........
Back in the day, DPMS made some rifles chambered in 300 RSAUM. The B&M case is a 1.95-2 inch RUM case, and these would be easy conversions to big bore. No bolt face work at all, and magazines already designed for the fatter cases. I had a couple of these, so sent those up to JD at SSK.
The first gun was a .500 caliber rifle, we call it the 50 B&M SA. The second was a 458 version of the same case, the 458 B&M SA. In my data here I show the first loads went down range in January of 2010. After going through the basics of getting them to work, which was really easy, some magazine tweaking by Brian at SSK solved all issues. Both rifles had 18 inch barrels. Both are heavy as hell at 10 lbs.
After getting basic data and making sure they worked, I put them to the side and did not mess with them at all for several years. I did not have much interest in them, and was heavy hunting during those years, and semi just had no place in my agenda at all. SSK built several rifles over the years, but I turned everything over to JD and SSK with these, I didn't want anything to do with them. They served no real purpose for me, other than just something to play around with.
Then in 2014 I more or less officially retired from Hunting. I got bored. So looking at these things in the racks, I decided to just find out what potential they had. I went to work on some serious load data for these things.
What I found with the 50 B&M SA;
300 gr Hornday 2400 fps
335 Raptors 2300 fps
350s 2200-2250 fps
375s to 2150 fps
400s to 2050 fps
I personally like the 458 B&M SA better;
The 250 Socom Raptor by CEB is a very serious .458 caliber bullet, and it is made for things just like this, along with the various bolt gun cartridges as well. And the main load for this gun
250 Socom Raptor 2670 fps
300 North Fork 2436 fps
300 Barnes TSX 2421 fps
325 Safari Solids 2327 fps
325 Hornady Flex 2350 fps
Various 350s from2150 to 2250 fps.
Once I got that done, lost interest again.... HEH......... Loaded up a few hundred of these in case there was a Zombie Apocalypse, and put them back in the rack again..........Where they remain today.........