.458 Lott load data

omeratwood · January 8, 2010, 12:08 PM

Does anybody have any load data for 458 Lott, 500 Grain Speer Trophy Bonded Sledgehammers. Using the following IMR powders?
In order from fastest to slowest burn rate I have:
IMR 4227
IMR 3031
IMR 4064
IMR 4831

I tried 70.0 gn of IMR 3031 set at 3.560" C.O.L. using 8 1/2-120 primers, out of a Ruger No.1 Tropical. With no signs of over pressure, however the recoil was more than I expected. 3 rounds in 5" @ 100 yards, however I did not bench shoot, but only rested it on a sand bag laid on an ammo can to check the speed, but the chronograph failed on us so we were more concerned with not damaging the rifle.

I am heavily invested in these 4 powders, and so far it's proven to work. Have to buy it in 40lb shipments to get the price down but cannot have more than 150 lbs. in the same building by Florida law.
I cannot find the load data online. I am trying to duplicate Federal Premium Cape-Shok ammo that is so accurate, but cost $174.00 for a box of 20 rounds.

**Unclenick** · January 8, 2010, 05:18 PM

If the Federal load recoiled less than that 3031 load, then they likely are using some special powder not available to the average shooter. Do you know what chronograph velocity you got out of the high-priced Federal stuff? IMR3031 is a bit as fast for that round. 4831 is too slow and you can't fit enough in the case to make enough pressure for it to be happy.

The only IMR powder I have data for is IMR 4895 from the Speer manual. With a Hornady Frontier case and Federal 215 primer and a 24" barrel, seated to 3.550" nd fired in a universal receiver, they report 76 grains to start and 80 grains maximum getting 2125fps and 2214 fps, respectively. The computer showed 1.5 grains less IMR 4064 would match peak pressure to the IMR 4895 pretty closely, so 74.5 rains to start and 78.5 grains maximum. But it gets 50 fps less velocity for that pressure, so it's not quite the right balance.

The manual says that Reloader 15 was the most consistent performer, also using 76 grains to start and 80 grains max, and getting 2149 and 2227 fps from the two. Federal uses RL15 in their Gold Medal Match .308 ammo. It is just possible that's what is in their .458 Lott load, but it apparently would have to exceed the Speer manual maximum if it is? With a 26" barrel QuickLOAD seems to think RL15 could just make it to 2300 fps in a 115 grain water capacity case, but its pretty much up against the limit, pressure-wise. QuickLOAD liked RL17 best for pressure at that velocity, but it isn't in the manuals. The charge also weighs more than the RL15 charge, and will therefore recoil a little more.

Keep in mind the bullet you chose has a higher start pressure than a common jacketed bullet, so 500 grain load data for other bullets may not necessarily be safe to apply. Good luck with it.

omeratwood · January 8, 2010, 07:18 PM

http://www.midwayusa.com/viewProduct...tnumber=898883

2165 fps. 24" barrel

Quote:

data for is IMR 4895 from the Speer manual. With a Hornady Frontier case and Federal 215 primer and a 24" barrel, seated to 3.550" nd fired in a universal receiver, they report 76 grains to start and 80 grains maximum getting 2125fps and 2214 fps, respectively. The computer showed 1.5 grains less IMR 4064 would match peak pressure to the IMR 4895 pretty closely, so 74.5 gns. to start and 78.5 grains maximum. But it gets 50 fps less velocity for that pressure

Thank you for the data. I hate to bother you with this, but do you know what those 4895 pressures are? I'm thinking it's got be in the range of 50,000 psi.
I mean... how much are we taliking about here at peak?

bfoosh006 · January 9, 2010, 08:33 PM

you can find tons of info for your Lott here..http://forums.accuratereloading.com/eve...look under "Big Bores" and "Reloading"

**Unclenick** · January 10, 2010, 07:37 PM

Omeratwood,

I'm not clear on the pressures because I don't know their case capacity, but I believe the upper load runs close to 55,000 psi based on moving 75% of the powder forward with the bullet, as happens in straighy cylindrical cases. In QuickLOAD, if I use the default case capacity of 110 grains of water, I get above 60,000 psi, but the velocity then gets too high to be believable, so I think this is part of QuickLOAD's lesser accuracy with straight wall cases that is encountered in some instances. It would take rigging a rifle with strain gauges to be sure what is happening? In the meantime, my best guess is 47,300 for the starting load and 54,600 for the max load based on tweaking the case capacity and percent powder thrown forward and matching Speer's velocities. It just isn't certain without pressure test validation.

January 8, 2010, 12:08 PM	#1
omeratwood Member Join Date: January 5, 2010 Location: Summerfield, Florida Posts: 23	.458 Lott load data Does anybody have any load data for 458 Lott, 500 Grain Speer Trophy Bonded Sledgehammers. Using the following IMR powders? In order from fastest to slowest burn rate I have: IMR 4227 IMR 3031 IMR 4064 IMR 4831 I tried 70.0 gn of IMR 3031 set at 3.560" C.O.L. using 8 1/2-120 primers, out of a Ruger No.1 Tropical. With no signs of over pressure, however the recoil was more than I expected. 3 rounds in 5" @ 100 yards, however I did not bench shoot, but only rested it on a sand bag laid on an ammo can to check the speed, but the chronograph failed on us so we were more concerned with not damaging the rifle. I am heavily invested in these 4 powders, and so far it's proven to work. Have to buy it in 40lb shipments to get the price down but cannot have more than 150 lbs. in the same building by Florida law. I cannot find the load data online. I am trying to duplicate Federal Premium Cape-Shok ammo that is so accurate, but cost $174.00 for a box of 20 rounds.

January 8, 2010, 05:18 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	If the Federal load recoiled less than that 3031 load, then they likely are using some special powder not available to the average shooter. Do you know what chronograph velocity you got out of the high-priced Federal stuff? IMR3031 is a bit as fast for that round. 4831 is too slow and you can't fit enough in the case to make enough pressure for it to be happy. The only IMR powder I have data for is IMR 4895 from the Speer manual. With a Hornady Frontier case and Federal 215 primer and a 24" barrel, seated to 3.550" nd fired in a universal receiver, they report 76 grains to start and 80 grains maximum getting 2125fps and 2214 fps, respectively. The computer showed 1.5 grains less IMR 4064 would match peak pressure to the IMR 4895 pretty closely, so 74.5 rains to start and 78.5 grains maximum. But it gets 50 fps less velocity for that pressure, so it's not quite the right balance. The manual says that Reloader 15 was the most consistent performer, also using 76 grains to start and 80 grains max, and getting 2149 and 2227 fps from the two. Federal uses RL15 in their Gold Medal Match .308 ammo. It is just possible that's what is in their .458 Lott load, but it apparently would have to exceed the Speer manual maximum if it is? With a 26" barrel QuickLOAD seems to think RL15 could just make it to 2300 fps in a 115 grain water capacity case, but its pretty much up against the limit, pressure-wise. QuickLOAD liked RL17 best for pressure at that velocity, but it isn't in the manuals. The charge also weighs more than the RL15 charge, and will therefore recoil a little more. Keep in mind the bullet you chose has a higher start pressure than a common jacketed bullet, so 500 grain load data for other bullets may not necessarily be safe to apply. Good luck with it. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 10, 2010, 07:37 PM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Omeratwood, I'm not clear on the pressures because I don't know their case capacity, but I believe the upper load runs close to 55,000 psi based on moving 75% of the powder forward with the bullet, as happens in straighy cylindrical cases. In QuickLOAD, if I use the default case capacity of 110 grains of water, I get above 60,000 psi, but the velocity then gets too high to be believable, so I think this is part of QuickLOAD's lesser accuracy with straight wall cases that is encountered in some instances. It would take rigging a rifle with strain gauges to be sure what is happening? In the meantime, my best guess is 47,300 for the starting load and 54,600 for the max load based on tweaking the case capacity and percent powder thrown forward and matching Speer's velocities. It just isn't certain without pressure test validation. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 9, 2010, 08:33 PM	#4
bfoosh006 Senior Member Join Date: February 17, 2009 Posts: 1,089	you can find tons of info for your Lott here..http://forums.accuratereloading.com/eve...look under "Big Bores" and "Reloading"