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?