Fiftydriver
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I was able to work up loads in one of my 510 Allen Magnum rifles for a customer this morning. This rifle uses a left hand McMillan single shot receiver, McMillan Big Mac stock, 36" bartlein 15 twist barrel, jewell trigger and one of my Super 6 port Painkillers. These are some of my favorite rifles to build. Been shooting the big 50s seriously since 1994 and love them. Hence my call sign, Fiftydriver!!!
Developed loads with the 750 gr. Hornady AMax projo and RL50 powder. Lit with a CCI-35 primer and an over all length of 5.800". RWS brass is the only brass I recommend in my 458 and 50 cal wildcats based off the BMG case.
Started at 245.0 gr and worked up from there. Jumped in 5 grain levels until velocity started to jump and then went to smaller increments.
245.0 gr.............2836 fps
250.0 gr.............2897 fps
255.0 gr.............3034 fps
257.0 gr.............3049 fps
260.0 gr.............3075 fps
261.0 gr.............3098 fps
262.0 gr.............3117 fps
263.0 gr.............3140 fps
I stopped at this point but still had no pressure signs and primer pockets were still tight. That said, i did step back to the 261.0 gr. load at roughly 3100 fps.
Thats 16,000 ft/lbs of kinetic energy payload!! And while the rifle does move significantly under recoil, its simply a slow push. It moves you back about 8" on the bench but not severe in any way.
Here is a 26 Nosler between two 510 Allen Magnum rounds. Bonus of the 510 Allen Magnum, you can shoot match grade 50 BMG ammo in these rifles. I say match grade because surplus 50 BMG ammo specs are not tight enough on the cases to fit in the chambers.
Amazing thing, the 510 Allen Magnum is not even the largest of my 50 cal wildcats based on the BMG case. My 510 Maximus holds around 25 grains even more powder then the 510 Allen Magnum. It does not have the ability to shoot standard 50 BMG ammunition.
Developed loads with the 750 gr. Hornady AMax projo and RL50 powder. Lit with a CCI-35 primer and an over all length of 5.800". RWS brass is the only brass I recommend in my 458 and 50 cal wildcats based off the BMG case.
Started at 245.0 gr and worked up from there. Jumped in 5 grain levels until velocity started to jump and then went to smaller increments.
245.0 gr.............2836 fps
250.0 gr.............2897 fps
255.0 gr.............3034 fps
257.0 gr.............3049 fps
260.0 gr.............3075 fps
261.0 gr.............3098 fps
262.0 gr.............3117 fps
263.0 gr.............3140 fps
I stopped at this point but still had no pressure signs and primer pockets were still tight. That said, i did step back to the 261.0 gr. load at roughly 3100 fps.
Thats 16,000 ft/lbs of kinetic energy payload!! And while the rifle does move significantly under recoil, its simply a slow push. It moves you back about 8" on the bench but not severe in any way.
Here is a 26 Nosler between two 510 Allen Magnum rounds. Bonus of the 510 Allen Magnum, you can shoot match grade 50 BMG ammo in these rifles. I say match grade because surplus 50 BMG ammo specs are not tight enough on the cases to fit in the chambers.
Amazing thing, the 510 Allen Magnum is not even the largest of my 50 cal wildcats based on the BMG case. My 510 Maximus holds around 25 grains even more powder then the 510 Allen Magnum. It does not have the ability to shoot standard 50 BMG ammunition.
