Post by Lee Martin on Sept 3, 2015 22:11:21 GMT -5
5-shots, 100 yards bench rested
.50 Alaskan Mauser
Bullet - 585 gr Martin LFN
Powder – 53.5 IMR 4198
Brass - Starline
Primer - CCI Large Rifle
Velocity – 2,000 fps
One squeeze felt off and I assume it landed at 4:00. Of course that may be wishing thinking. Otherwise I would’ve had 0.78” center-to-center.
I never expected this thing to do a minute when building it. There’s no magnification with the sights, just an UltraDot. At setting #2 the POA covers the orange. All the same it’ll hold 1.0 – 1.5” at 100 yards with our 585 gr LFN.
.50 Alaskans – 525 WFN left, 585 Martin LFN right:
Word of warning – this charge is tailored for bolt action Alaskans. I’m pushing pressure beyond what I consider safe for Marlins or Winchester 71s. “Load from a Disc” pegs it at 46,000 PSI. Bearing in mind the Alaskan’s head diameter, don’t try them in a lever rifle. Your Guide Gun may be happy with a .450 Marlin at that clip but won't be with a .50-cal. As with so many internet discussions I hate how pressure gets thrown around without completing the equation (the same holds for heat treating and alloy specifications). Example:
.223 Remington at 55,000 PSI
.50 Alaskan at 40,000 PSI
Bolt thrust = Pressure x Area
Area = (pi) x (radius)^2
Radius .223 Rem = 0.188”
Radius .50 Alaskan = 0.277”
.223 Rem @ 55,000 PSI = (55,000) x (3.141) x (0.188)^2 = 6,105 ft-lbs
.50 Alaskan @ 40,000 PSI = (40,000) x (3.141) x (0.277)^2 = 9,640 ft-lbs
Despite 27% less pressure, bolt thrust is 36% greater. Other factors not reflected here include chamber grip, lug bearing surface, and throating.
While we’re talking numbers, 585’s going 2,000 fps generate 5,200 ft/lbs of energy. Right up there with the Rigbys, Jeffreys, .458 Win Mag, and other classic stoppers. And you guessed it. This rifle isn’t pleasant to shoot off the bench. I got a workout sending fifty down range last Saturday.
-Lee
www.singleactions.com
"Chasing perfection five shots at a time"
.50 Alaskan Mauser
Bullet - 585 gr Martin LFN
Powder – 53.5 IMR 4198
Brass - Starline
Primer - CCI Large Rifle
Velocity – 2,000 fps
One squeeze felt off and I assume it landed at 4:00. Of course that may be wishing thinking. Otherwise I would’ve had 0.78” center-to-center.
I never expected this thing to do a minute when building it. There’s no magnification with the sights, just an UltraDot. At setting #2 the POA covers the orange. All the same it’ll hold 1.0 – 1.5” at 100 yards with our 585 gr LFN.
.50 Alaskans – 525 WFN left, 585 Martin LFN right:
Word of warning – this charge is tailored for bolt action Alaskans. I’m pushing pressure beyond what I consider safe for Marlins or Winchester 71s. “Load from a Disc” pegs it at 46,000 PSI. Bearing in mind the Alaskan’s head diameter, don’t try them in a lever rifle. Your Guide Gun may be happy with a .450 Marlin at that clip but won't be with a .50-cal. As with so many internet discussions I hate how pressure gets thrown around without completing the equation (the same holds for heat treating and alloy specifications). Example:
.223 Remington at 55,000 PSI
.50 Alaskan at 40,000 PSI
Bolt thrust = Pressure x Area
Area = (pi) x (radius)^2
Radius .223 Rem = 0.188”
Radius .50 Alaskan = 0.277”
.223 Rem @ 55,000 PSI = (55,000) x (3.141) x (0.188)^2 = 6,105 ft-lbs
.50 Alaskan @ 40,000 PSI = (40,000) x (3.141) x (0.277)^2 = 9,640 ft-lbs
Despite 27% less pressure, bolt thrust is 36% greater. Other factors not reflected here include chamber grip, lug bearing surface, and throating.
While we’re talking numbers, 585’s going 2,000 fps generate 5,200 ft/lbs of energy. Right up there with the Rigbys, Jeffreys, .458 Win Mag, and other classic stoppers. And you guessed it. This rifle isn’t pleasant to shoot off the bench. I got a workout sending fifty down range last Saturday.
-Lee
www.singleactions.com
"Chasing perfection five shots at a time"
