303 Britiish to 444 Marlin

[brstevns]

Can 303 British be fire formed to 444 Marlin. Asking for a cousin?

[rmatchell]

Pm on the way.

[brstevns]

Would there be any other brass that he could form to 444 marlin? 356 or 308 marlin maybe?

[GhostHawk]

They do it the other way round, use .444 Marlin to make brass .410 shotshells.

.444 marlin brass is hard to find just now, best bet is to put up a WTB and be patient.

[kenyerian]

http://www.marlinowners.com/forum/444-marlin/69699-making-444-marlin-brass.html. Here is an interesting thread on the Marlin Owners website. You might have to register to see all of the links. The only cartridge with the same base diameter is the 30-06 and the 8x57. However they are rimless so they don't eject very well. However you can use them in an emergency situation to make 444 brass. If you have a copy of the 10'th edition of the HandLoader's Digest it has a great article on the 444

[Hamish]

A couple days agoI was contemplating this very subject. The rim would have to be turned down, possibly thinned slightly according to your application.

I believe the only real item of concern is the base of the .303. I don't think it would take many full house rounds, but should be fine for light loads. I will be converting some to try myself in the next couple of weeks.

[brstevns]

A couple days agoI was contemplating this very subject. The rim would have to be turned down, possibly thinned slightly according to your application.

I believe the only real item of concern is the base of the .303. I don't think it would take many full house rounds, but should be fine for light loads. I will be converting some to try myself in the next couple of weeks. Late me know how it works for you.

[Mk42gunner]

.303 British to .444 Marlin?

Judging from my failed efforts to blow out brand new .303 brass to make .410's, no it is not a good idea.

I tried straight from the Winchester plastic bag, neck expanded, annealed, you name it; nothing got rid of that pregnant guppy look. I did think of one way that might work, but I didn't have a working lathe to try it: A long .410" expander to reach almost to the bottom of the case.

I realize the rifle loads will be higher pressure than what I was willing to load into my Grandpa's Iver Johnson Champion, but I think I would still hunt for some correct brass.

Robert

[longbow]

30-40 Krag at 0.4577" is a couple of thou larger at the head than .303 British at 0.4554 but still well under the .444 Marlin at 0.4698". Both have larger diameter rims as well.

As stated above, they may be okay for light loads but that is a lot of expansion for the smaller head and since it has very thick sidewalls at that point most expansion will likely show up as a bulge a little ways up from the head.

I always liked .444 Marlin but brass is not cheap or common. I never bought one for that reason.

Longbow

[EDG]

When you talk about head diameters never rely on the books.

Cartridges have tolerances and the diameter of cartridges are always toleranced plus .000 minus something so the real dimension is always smaller than the drawing specification.

[SquirrelHollow]

When you talk about head diameters never rely on the books.

Cartridges have tolerances and the diameter of cartridges are always toleranced plus .000 minus something so the real dimension is always smaller than the drawing specification.
Exactly.
I actually have a 6mm wildcat that was built specifically with the "sub"-tolerance in mind.

It's essentially a .243 Winchester, but the chamber is ridiculously tight. It was spec'd for R-P brass to chamber without having to force the bolt, but to also have essentially ZERO expansion when fired. ...Which is exactly what happens. Fired cases come out with exactly the same body and shoulder dimensions, and a neck that's just 0.003" larger in diameter.

The reason for it is that R-P .243 Win brass is substantially under-sized from the factory (loaded ammunition as well). So, even though I have a chamber so tight that it's smaller a "Match" chamber, I can still run R-P factory ammo if needed. And most brands of brass chamber with minimal, if any, resistance.