I was wondering if anyone knows how these might be loaded. They claim pretty impressive velocity.

I'm not trying to recreate these specifically. More just curious if any of my loads are approximating theirs.

For example, are they close to a max load of H110 or 2400 or do they have some proprietary powder?

https://www.midwayusa.com/product/926010/buffalo-bore-ammunition-357-magnum-158-grain-semi-jacketed-hollow-point-high-velocity-box-of-20

Wouldnt get there with 2400..

H110 or 300MP?

I thought their claim to fame was their bullet.  I know they also have a hot load in most cartridges but a careful reloader can usually work up a safe, maximum load, like they do.  But wasn't it the bullets that were special and not available as reloading components?

I'll have to get out my revolver data and compare notes with them.  My data was with W296/WSPM.

I never got close with a full load of H110 in my Henry carbine. Even going over max. Once I went past max they started get tough to extract. It could be my gun as Ive never shot Buffalo Bore. With 158gr JHP, the fastest I got was 1800fps.

Claims on the Box and data from an actual Chrony in the field are two different things.  If you get what I am saying.  

True, but they have actual data from different guns. For example,

3 inch S&W J frame
19C/20-158gr. Jacketed Hollow Point = 1398 fps

4 inch S&W L frame Mt. Gun
19C/20-158gr. Jacketed Hollow Point = 1485 fps

5 inch S&W model 27
19C/20-158gr. Jacketed Hollow Point = 1457 fps

Try Lil' Gun for those velocities. I don't believe Sundles is using any exotic bullets. I used to correspond with him quite a bit in the olden days and the guy definitely knows what he's doing.

I can duplicate their 180 gr cast load in a 6" GP100, but have to go over book max with Win 296.  Don't know that I would try it in a non Ruger revolver

Good to know. It could be my rifle.

Commercial ammo manufacturers can load a mix of powders to get specific performance not available to the average handloader without the sophisticated pressure and burn testing equipment they have.  For example, with a std max load of 16.7grns load of H110 and a Zero JSP 158grn bullet, at 6,100ft on an 84° day, I was only able to squeeze out 1,8227fps out of my 24" Rossi rifle and 1,7891fps from my 20" Rossi carbine and with a 'Elmer Keith' level powder load of H110, I could only manage 1,977fps and 1,941fps respectively.  That's well below the 2,153fps they claim they got with they 158grn 357mag Heavy in a shorter 18" Marlin.

Note that my loads produced higher velocities in the longer barreled rifle with both magnum loads.  I don't know if Buffalo Bore's ammo would produce higher or lower velocities in the longer, 24" barrel as they may have optimized it for the shorter carbine length.

While I understand the concept of replicating "factory"* loads, I do not understand the quest for speed to the exclusion of all other considerations.  There is discussion of going over max and "Elmer Keith loads", as if that in some way justifies a home reloader going into unknown and potentially unsafe terrain.  Where is the accuracy info that goes with all the Buffalo Bore loads and the replicants?

Just something to think about before doing this on your own without the calibrated pressure testing equipment a professional laboratory would use.  Someone needed to say it in this thread, so there it is.


* Does Buffalo Bore qualify as a factory or are they more of a boutique or a custom loader?

True.

Most (but not all) velocity data comes from a barrel of unknown length with no cylinder gap like you would have on a 357 revolver.

A guy might be able to come close to duplication it with something like a 14 inch TC Contender barrel.

Please define what you consider to be an "Elmer Keith" load.