.458 American Express:

[Maverick223]

I've been talking about it for a while now, and finally, It has begun...

The rifle, a Browning/Miroku clone of the Winchester 1885 Highwall, is at the smith; the reloading dies, brass, and bullets have arrived. I'm getting ready to start handloading in preparation for the day the smith calls for pick up (which may very well take a while, it's a fairly simple task, but he has a backlog just like anyone else worth taking something to).

The chambering is more appropriately described as a .45-120Sharps (which, in itself is inaccurate, as it's origins post-date the close of the Sharps Firearms Company), but the load I'll be working up exceeds the performance of said cartridge by a vast margin (~400% or so), so I thought it deserved a new name. It shoots a .458 caliber projectile, it's an American design, and I believe the performance entitles it to the prestigious express designation. I'm shooting for .450NE specs. at fairly low pressure levels (sub-40kPSI), so as to drive a 480gr. solid at 2150fps.

Here are a few photos of the rifle and a dummy round I made up for the smith (to ensure that the throat is sufficient for the somewhat long bullet):


1885 Highwall with 28in. heavy octagon.


.458AmEx in calipers, pictured with mainstream cartridges (.30-06Spd., 7.62x39mm, .223Rem., .45ACP, 9mmPara, .44RemMag., .357S&W, .17HMR, & .22LR).


.458AmEx pictured in center alongside other large cartridges (4Bore, .700NE, .577T-Rex, .50BMG; .458WM, .45-70Govt., .375H&H, & .30-06Spd.).


Please kindly refrain from asking what I'm building this for or how unsafe the load is...I'm building it cause I want it and I've crunched the numbers and the load is just as safe as [actually safer than] my current .45-70Govt. load.

If anyone has any recommendations for smokeless powder types and/or charges I'm all ears. I'm looking to create two distinct loads. The aforementioned stopper (which I have been working on for a while now) and a lighter, very low pressure load that mimics the performance of a moderate .45-70Govt. (300gr. HP @ 2000fps or thereabouts). My plans for the former is ~97.0gr. of RL-15 (which I already stock and like, it works nicely in my .375H&H), and the latter will likely involve something like a light load of IMR SR-4759, Accurate XMP-5744, or perhaps even a case full of TrailBoss (though I think this might fall well short of the desired velocity).

Anyway, what do you folks think?

 

[meanmrmustard]

Buffalo slayer if I've ever seen one. It's beautiful.

 

[Maverick223]

Thank you sir; I don't think there is a safe Buff. on this continent or any other...just as long as they come one at a time.

 

[firesky101]

So... Mav, you gonna shoot this in one of your contests when you get it?

 

[Maverick223]

Doubt it, not with the heavy load anyway. I think I'll limit this one to short strings; not because of the recoil, per say, but to prevent damage to my eyes. When I get a light load perfected we'll have to see how she does.

 

[x_wrench]

GOOD GOD MAN, HAVE YOU THOUGHT ABOUT YOUR POOR SHOULDER! LOLOL!!! it looks great. i have thought about the same idea a few times, but i was not sure if anyone made a rifle that would take the abuse. nice to see i am not as strange as i thought i was. good luck with the BEAST! and the beasts will need a LOT of luck once that thing is pointed at them. as far as powders, IMR 4198 came immediately to my mind. but i have to admit, i like that powder for a lot of loads.

 

[Maverick223]

My shoulder loves a good workout from time to time!

As far as the rifle strength goes, any .45-70Govt. single shot (good luck fitting that cigar case in a repeater) that can withstand "Ruger No. 1 loads" is perfectly capable of the chambering as long as there is enough meat on the bbl to accept the longer chamber (being a straight-taper cartridge, this is an unlikely problem, but deserves mention nonetheless). It can be considered the poor-man's .450NE 3.25in. as it is nearly identical in dimensions and case strength (and brass is cheaper).

I'll look into IMR-4198, that may work nicely for the light load. Thank you for the recommendation.

 

[Sam1911]

That one screams for a Trail Boss load to plink with. That would be a lot of fun, though still a pretty serious thumper. I'd imagine it would be about like a .454 Casull out of a rifle.

 

[Walkalong]

Sounds about right. I get .44 Mag from a pistol performance with Trail Boss in .458 Win Mag brass.

 

[fireman 9731]

Trailboss is a favorite of mine for light 45-70 loads. I think it would perform very well in this case.

Are you just using 45-120 brass?

If you are, I would call it the 458 Quigly Express.... Just because I love the movie.

 

[Maverick223]

Trailboss is certainly still on the table, and will almost certainly be tried at some point. It's a good *safe* choice (whereas the lighter loads using a partially filled case, may not be). It has the side benefit of making costly brass (about $2/ea) last just about forever too.

Ordered some standard Norma .45-120 a few days ago, arrived yesterday. It's fairly thin at the neck, but I'm still hoping to get several hot loads out of it (will be neck sizing only).

I'm sure it comes at no surprise that Quigley is part of the inspiration, but I think I'll reserve that name for the Sharps '74 that I hope to acquire some day. Just doesn't seem right to use that name on a Winny falling block.

 

[browningguy]

Looks good, and should put a butt whuppin on your shoulder shooting off the bench. I have one of the Taditional Hunter models with octagon barrel, peep sights and a curved metal butt plate. I'm running 45-70's in Starline brass, 350 gr. SP at almost 2400 fps, and you feel it shooting off a bench. It's not bad at all standing though.

 

[weeniewawa]

I am wondering how long until the credit card company sends a cease and desist order
looks like fun tho

 

[Maverick223]

browningguy, that is pretty near my current load (though I shoot either 300s or 405s). Powder compression is such that I have to use the Lee Factory Crimp die or it'll pop the bullet out, but I've had no signs of excessive pressure.

weeniewawa, lol. I'm hoping that they're too afraid to confront me with the idea once they see the size of the cartridge.

 

[Jim Watson]

A friend has a .450 BPE. I'll see what he uses for his Nitro For Black loads. That would be about right for your "light" load; lighter than .450 Nitro at least.

 

[Maverick223]

I'd appreciate that, Jim. IIRC the BPE is the same case as the NE (rifle just isn't nitro-proved, so pressures need to be kept lower) so that sounds like it may be just about right.

 

[ShadowsEye]

Just checking to see if someone made a "Don't leave home without it" joke yet. Carry on.

 

[Maverick223]

Just checking to see if someone made a "Don't leave home without it" joke yet.

I would take it grocery shopping...but I'd need a bigger wallet.

 

[Hizzie]

Looks like a nice rifle. With a case that large don't see a problem. Looks very similar to the 458 3" Rimmed Express from South Africa, although that runs a little hotter. The idea was the same - use a larger case to lower pressures.

http://www.458express.com/

 

[Jim Watson]

My contact says:

"I used 50 gr. of 3031 with a 300 gr. cast bullet for 1650-1700 fps. I don't know if this will help with a heavier bullet. I have to use the lighter ones due to the slow twist."

 

[Maverick223]

Hizzie, that .458Express is about the same case capacity (despite being a bit shorter), but it operates at far greater pressures than I am looking to reproduce (it's 61kPSI, I want to maintain maximum pressures below 40kPSI to increase case life and consume less powder).

Jim, that's a great help, the light load (both in terms of power level and bullet weight) is the one I was mainly looking for advice on. I'm pretty sure of my heavy load, as I like the results that I have gotten from RL-15 in my .375H&H (and it's one less powder to stock).

*As a side-note, I wonder what it would take to make this cartridge legal for lg./dangerous game use in Africa (which isn't in the cards right now, and even if it was I doubt I'd be brave enough to use a single-shot, but it's an interesting concept nonetheless)?

 

[gp911]

Nice work putting it next to a 4 BORE, a .700NE, and a .577T-REX! Suddenly it seems so tame and misunderstood... That should be a wicked round, thanks for sharing it with us!

 

[Robtattoo]

It kills me that the 4-bore round is a soft-point. Like it'd make a bit of difference!

I have no experienced advice or help to offer, but as a big proponent of 'bigger is better' I really have to take my hat off to you!

I really don't imagine that you'd have any trouble getting the round approved for the Big 5 in Africa. 99% of the fellas I know that've hunted them have used either .375 H&H or .416 Rigbys. One Particularly good friend of mine, now guiding Buffalo hunters in Australia, has taken Leopard, Cape Buff & Giraffe with a .50 roundball. Nooooot forseeing many issues with ANY centerfire starting with a 4!

 

[Maverick223]

Nice work putting it next to a 4 BORE, a .700NE, and a .577T-REX! Suddenly it seems so tame and misunderstood...

Hehehe, it is tame

compared to the ones on the left.

 

[Robtattoo]

One quick question: Other than it not being a rimless, belted casing, how h=far does it deviate from the dimensions of a .458 LOTT?

Would loadings for this cartridge possibly work for you? I know the LOTT produces around 62K psi in full loadings, but would reduced load info be any use?