.577-450 questions

D

Dre_sa

New member
Hey folks!

As mentioned in another thread in a different part of this forum, I have recently undertaken a project in the form of a Martini Henry.

While I gather more information to make a better decision, I have a question to ask about reloading for this beastly rifle. I shall ask it in the form of a knock-knock joke just to spice things up.

Knock knock

Who's there?

Is a crimp

Is a crimp who?

Is a crimp necessary on a .577-450?

That's my question. I understand that crimps serve several functions, mitigating bullet creep or setback under force of recoil, but since the martini is a single shot rifle, that should in theory negate the need for a crimp in that regard.

I also believe that a crimp may lead to more consistent pressures while the powder combusts, or at the very least prevents the bullet from exiting the case under pressure from the primer alone. Since it's a black powder cartridge, pressures will be lower than smokeless/nitro powders.

So is a crimp really necessary in a .577-450?

Thanks for the help all, I do appreciate learning form more experienced folks.
 
Depends on the load. Same as any other cartridge.
If you don't have the right size press, it won't matter anyway. Rim diameter is .760". Uses 1.25-12 thread dies. Lee die set for Lee Large Series Press runs $87.99 at Midway. Comes with a roll crimp die, that adjusts from a light taper to full roll.
http://stevespages.com/jpg/cd577450martinihenry.jpg
No crimp for the .pdf cases I mentioned on the other post. They're really a chamber insert.
 
Pretty much just feel. Experience will tell you alot. Theres alooot of discussion about when to crimp vs when not to. Basically boils down to if the gun recoils hard and holds more than whats in the breach, crimp, if not its not a big deal.
Brass case necks will only hold so much tension before they stretch. So if the tension feels right, its right. If you press a bullet into place and your reaction is "whoa, that felt way easier than the others" the neck is probably worn out and the case needs to be tossed. For your shoulder fired cannon I wouldn't worry to much about crimp.
 
If you've got good neck tension around the bullets, are shooting from a bench primarily, and your ammo isn't crossing the Transvaal in the back of a munitions wagon, and then you're not running from a Zulu who's intent on ventilating you with a spear...

You probably don't need much of a crimp.


Oh, and remember...

When firing your Martini-Henry with service loads, that nice scallop on the right rear of the receiver is where you put your right thumb.

If you wrap your thumb around the wrist of the stock there's a pretty good chance you'll break your nose.

If yours doesn't have that little scallop (later ones didn't) the stock dimensions were altered that that wasn't as much of an issue.
 
If you have good neck tension on your reloads, then an additional crimp should not be needed. It's a single-shot after all, unless your MH has been modified to be box magazine fed:D
 
Over at youtube, IraqVeteran8888 has some videos on making the brass, casting the bullets, and loading those stomping big cartridges that might be helpful to you.
 
I have indeed seen that video, perhaps 8 times :)

He is reloading for at least two rifles making sizing necessary. from what I gather that may not be necessary if the brass is to be used in just one rifle.

which just leaves neck sizing and crimping, which I think may not be entirely necessary for just one single shot rifle.
 
Neck sizing will most definitely be necessary to some extent, or you likely won't get any neck tension at all.

Full length sizing, that depends on how springy the action is.
 
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