My fitter-and-turner buddy has lengthened the throat in my Winchester/Miroku 86 to give a bit more oomph and flexibility in the loads (some flat-nosed bullets could barely be crimped into the cannelures before).

He's only added another 5mm, rather than the 7.5 that would make an ersatz .45-90, but that is enough to seat some bullets out to a 2.8" COL, the longest that will work through this action.

My problem now is to work out some increase in the powder weights that might improve velocity, at least in my Miroku, which may be a bit on the tight side. I found some tables for the .45-90 but they are more conservative than many published for modern lever-actions in .45-70.

Part of the issue, I suppose, is how much energy is lost when the powder space is increased, and how much more powder is needed just to make that up. As food for thought on this I notice that some .45-70 lever-action loads list about 2000fps for a 400-grain bullet from 50 grains of powder while the long .450/.400 needs 80 grains, notwithstanding the differing bore sizes, propellants and allowable pressures.

If anyone has sexy .45-90 loads, I'd like to take a look and possibly split the difference between them and those for an ordinary .45-70.

Thanks in anticipation

S338,

There aren’t many published loads for the 45/90 and, as you say, most are very conservative.

Older Lyman loading manuals listed a 405gr pill at 1945fps but loads for modern leverguns in 45/70 exceed that load.

If you go to Hodgdon’s Reloading Centre and look up loads for the WWG 457 mag, that load data will provide you with some reasonable guidance. OAL is 2.65”.

The WWG 457 mag is simply a lengthened 45/70 and was designed so it could not be loaded into a regular 45/70 chamber. The loading data is pressure tested and you can compare with Hodgdon’s 45/70 data.

Provides some idea my 45-70 Handi-Rifle throat lengthened about 5mm to reduce seating depth/increase case capacity. This action probably a bit more rigid than yours. Before and after compared increased powder charge gains about 150 fps muzzle speed with 400gr bullet.

Can't possibly compare a straight case to a 450-400, so don't try.
As for a 45-90, realize that that was a 300 grain express loading, and had a 36 inch twist.
You do not have a 45-90; you have a 45-2.4 inch Sharps.
It is hard to work up loads when you can't approach normal pressure signs like primers and case sticking; you have already exceeded the rifle design parameters.
I use 70 grains of Goex Cartridge, on top of 7 grains of 5744 in my 45-2.4 Sharps.
No help, I know.

Thanks everyone.

I looked up that WWG 457 Mag, JFE, and noticed a slight advantage in the starting load with the 405-grain Remington bullet, which I haven't seen around yet, but the maximums seem much the same. The Woodleigh 405s I've got are the ones that gave trouble with the cannelure. I can get them to crimp with the short Hornady cases but that must limit the powder space even on the standard .45-70. lengthening the COL will either require me to use the Lee factory crimp die or keep the ammo for single loading.

I see the 457 mag trim length is only 2.1", too. So is the WWG case longer, or just the throat and loaded ammo?

Sorry to disgust you with my analogy, dpcd. I don't have any immediate plans to load 300-grain bullets - but do you see the 20-inch twist as likely to add significant pressure over the 1:36?

The trim to length on the Hodgdon site is a typo - the case length should be 2.20” long. It also has a longer throat than the 45/70. You can find the chamber drawing details at the SAAMI site.

https://saami.org/wp-content/u...-14-Posting-Copy.pdf


Personally, I think a 400gr pill at around 2100fps or a 350gr pill at 2200fps are fairly decent loads.

What were you expecting?

Not even that much, Joe, but I'm a chicken reloader and got a bit concerned when 350-grain Speers at the base AR2207 load caused more expansion just past the solid head than I'd noticed with any other factory or hand load I'd measured, before the throat was lengthened.

I've got some Hornady 350-grainers now and I would be happy if I could get them to 2050fps and the Woodleigh 405s to, say, 1950fps without flat primers or any other concerning pressure signs.

Am I right to think the 457WWG, like the .45-70, also has next to no throat?

quote:

Originally posted by sambarman338:
Am I right to think the 457WWG, like the .45-70, also has next to no throat?

It has a longish leade that seems identical to that of the 450 Marlin. In effect it’s just under 0.2”.

When it came out there were claims of factory ammo producing 2100-2150fps in the 400gr loading and 2300fps in the 350gr loading.

Your velocity goals should be easily achievable.

Thanks, I'll keep plugging along, starting my AR2207 loads again with the CCI200 primers and the Hornady 350-grain bullets mentioned in the ADI manual.

I weighed the various cases here and was surprised at the difference between PPU (about 164 grains), the short Hornady (about 187.5) and Starline (200 grains).

Filling similar length cases with water I found the PPU would hold 80 grains but the Starline only 76.5, and I'm wondering now if that is why the latter showed pressure, having less powder space (I don't have the Winchester cases listed in the book, but may get some).

That said, seating bullets out farther should even things up. I must get a chronograph that makes sense at our range.