StumpGrinder
Well-Known Member
The 458 SOCOM is vastly under rated and often unfairly compared to the 450 Bushmaster of different bullet weights and barrel lengths. The Bushmaster is great for communist states that require use of straight wall cartridges. But in the free states we are not limited to that so I prefer the 458 SOCOM because it has a wider range of rifle caliber bullet weights from the 150 grain poly bullet to 600 grain subsonic. I'm not interested in shooting subsonic so I will only show the unfair advantage being given the Bushmaster at the expense of the SOCOM. Hornady has thrown their weight behind the Bushmaster and are therfore giving it preferential treatment. The SOCOM gets no love from the major manufacturers so it has become primarily a Handloaders cartridge. Which is fine for me because I am one! I also recently got the Labrader so I can accurately verify my results.
In the Hodgdon 2025 annual manual, the first loading for the SOCOM is 250 grain tsx with top velocity of 1991. With that same bullet, using a starting load of 36 grains of Accurate 11 fs and Remington 7 1/2 primers I got 2030 fps. Working up in half grain increments to 40 grains I reached 2200 fps with absolutely no pressure signs. I am using a Bear Creek Arsenal side charging upper with a disabled gas block. So it is straight pull bolt action with a 14 inch barrel. It was the only barrel length offered at the time. I would love to see Howa make this in a 1500 Mini with a 22 or 24 inch barrel. It would probably add at least 100 fps. In the Hodgdon manual they don't list a 250 grain tsx but the do list a Nos JHP at 2147 and an FTX at 2289 with Little Gun and 2240 with 41 grains of H110 compressed. Accurate 11 fs is in the same burn rate as H110 and some have stated that it is basically H110 with a flash suppressant added. Hanloader tv compars it more to Power Pro 300 MP. Hornady has been known to inflate their box posted velocities so I question these also. The Bushmaster load data was from a 24 inch barrel and the SOCOM from a 14 inch barrel. Not at all a fair comparison!!! The Sierra manual lists both calibers with 300 grain bullets, both with 24 inch barrels. Top speed for the Bushmaster is 2000 fps and the SOCOM is 2100. So in an apples to apples comparison the SOCOM wins, by a little. For refrence, the same bullet in the Trap Door 45-70, with a 32.5 inch barrel is 1700. In the 1886 Winchester with 26 inch barrel, top velocity is1850. And for the more modern rifles like the Marlin 1885 and Ruger No.1 with 22 inch barrel the top velocity is 2200 fps. However it takes 10 to 15 more grains of powder to beat the SOCOM by 100 fps.
In conclusion you can see that given an even playing field, the 458 SOCOM meets or exceeds the 450 Bushmaster, and is in fact a modern 45-70 on an AR 15 platform. At least with this weight bullet. Of course the modern 45-70, with its longer case would certainly out perform the SOCOM with heavier, longer bullets.
