.577/450 reloads?

Pumpkinslinger · Posted: Wed Feb 23, 2022 6:02 pm Post subject: .577/450 reloads?

Has anyone here tried loading for a .577/450 cartridge? I picked up a Martini-Henry Mk IV last weekend.

slimjim · Posted: Wed Feb 23, 2022 9:01 pm Post subject: Re: .577/450 reloads?

Lucky guy! Are you going to use black powder or a substitute?

I'm not sure if this is useful. Instead of using BP in my 45-70 rolling block, I used H4895. It was a lower chamber pressure than BP.

Pumpkinslinger · Posted: Thu Feb 24, 2022 10:24 am Post subject: Re: .577/450 reloads?

Well... Dies seem hard to come by and require a 1.25" x 12 threaded press. Brass looks scarce too. But I think I've found a short term solution so I can at least play with the rifle.

An insert to allow the .577/450 to fire .45 Colt cartridges:
www.theshootersbox.com...35370.html

A hollow base bullet to allow for the difference in groove size (the rifle takes a .458 to .460 bullet, while the .45 Colt is .452 to .454):
www.mattsbullets.com/i...gsa7bq5lu5

I've also got a bunch of .454 bullets, 250 and 300 grain, I could try.

slimjim · Posted: Thu Feb 24, 2022 12:07 pm Post subject: Re: .577/450 reloads?

Keep the chamber pressure low, and the brass you find should last a long time.

.458 is the bullet diameter for a .45-70. Plenty of those available but prices are higher than I remember buying for my reloading.

I was wonder if you could have a machine shop modify a Lee Classic die but the .577/450 cartridge is a much bigger case than a .45-70,

They may have brass

www.ammunitionartifact...tini-henry

Note, old-time reloaders of .45-70 told me I didn't need to crimp or have a lot of neck tension. It was ok to be able to turn the bullet in the case.

Aloysius · Posted: Thu Feb 24, 2022 12:22 pm Post subject: Re: .577/450 reloads?

Pumpkin, in 45 BP there are lots of molds available from ball till very large conical. When you barrel has a fast twist you might have a look at the bullet for the Parker Hale Volunteer, that's a Withword. I have to look it up, but I think its a Lyman mold. And when you use a pure lead bullet, what can go wrong?

gelandangan · Posted: Thu Feb 24, 2022 3:18 pm Post subject: Re: .577/450 reloads?

Sounds like a fun thing to use Smile

Keep us updated Pumps

Pumpkinslinger · Posted: Thu Feb 24, 2022 4:33 pm Post subject: Re: .577/450 reloads?

I have .458 cast bullets for my .45-70s. Might be able to seat them in the .45 Colt case by using the .45-70 expander die. The original bullets for the .577/450 were paper patched, which is another thing I could play with. And... Maybe make an insert to convert to .45-70?? I don't have the tools for that though. This is going to be a fun project!

Aloysius · Posted: Fri Feb 25, 2022 2:50 am Post subject: Re: .577/450 reloads?

Think a moment about when, where and who made that round. You don't have to invent the wheel twice. In that erea they developed the Parker Hale Volunteer (muzzleloader), the .577 Snider and your .577/450... I guess they all had a fast twist and used rather heavy bullets... so your cast bullets for the .45 Government is the way to go IMHO.

Elvis · Posted: Fri Feb 25, 2022 2:52 am Post subject: Re: .577/450 reloads?

will watch with interest....Im still looking for correct size ball fishing sinker.... would be nice to find one,just for grins n giggles.

Pumpkinslinger · Posted: Fri Mar 04, 2022 11:28 am Post subject: Re: .577/450 reloads?

Stuff got here

EDIT - When I posted this pic I noticed some dark spots in the hollow bases. Yep, some small voids. We'll see...

Aloysius · Posted: Sat Mar 05, 2022 2:05 am Post subject: Re: .577/450 reloads?

Put them on a scale and you'll know if it's OK or not

Elvis · Posted: Sat Mar 05, 2022 2:15 am Post subject: Re: .577/450 reloads?

for what you intend to use them...yeah to heck with it...chuck em on scales and anything much lighter than others keep for plinking... all the correct weight should be fine.

Pumpkinslinger · Posted: Sat Apr 02, 2022 12:44 pm Post subject: Re: .577/450 reloads?

I finally got around to loading some of this ammo. I weighed a dozen or so bullets, with and without visible voids, and they were consistently 260 to 262 grains. So I didn't sort them. We'll see how that works...

I used Universal Clays, mostly because I have a lot of it and it's always given me satisfactory results. I decided to use rifle primers because the M-H seems to have a pretty heavy firing pin strike, based on a little dry firing. I think the rifle primers will be less likely to be perforated.

Because I got interrupted while loading these I took the extra precaution of weighing them when I was done. All weighed 385-387 grains except two. I had one at 391 and one at 397! Obvious double charge, right?

I pulled both and weighed the charges. Both were really close to target, I did lose a little while pulling. I weighed the bullets and one was 265 grains. It had a little "wart" in the base. The other was fine. So I weighed the cases and sure enough one was 10 grains more than the rest. I have no idea why, there was no visible reason. I reloaded both and marked them with a Sharpie so I'd be able to see if they shot differently. Since I'm using a fairly mild load I think they're safe to try.

Vince · Posted: Sat Apr 02, 2022 3:10 pm Post subject: Re: .577/450 reloads?

It sounds like you have a decent handle on reloading for this old beast Punkin.

I’ve never had anything to do with loading for a BP or old cartridge, so I’m watching this with much interest mate.

Elvis · Posted: Sun Apr 03, 2022 10:03 pm Post subject: Re: .577/450 reloads?

sounds like fun.....good on you for double checking.