.450 marlin

[HarryN]

Hi, I am studying the .450 marlin as an option for a 14 inch custom pistol project.

There aren't too many factory load options, I am trying to retain some hand function after enjoying the use experience, and I live in a no-lead state, so hand loading is a given.

In case you are not familiar with this round, it is essentially a 2.1 inch long daughter of the .458 win mag, and a cousin of the .458x2 American round.

The interesting and challenging difference is that it has a wider belt , apparently to avoid dangerous mis chambering of similar rounds.

 

[HarryN]

One of my concerns is that this specialized brass might be sometimes difficult to obtain, so I am looking for a solid, but "backup" method to make it from a more popular brass, for example, hornady belted brass basic. This is just straight wall belted brass.

I need a die path to take care of any forming details, as well as a method to add more width to the belt.

 

[HarryN]

For the belt, I was thinking about having some thin brass rings made, and either heat shrinking or swaging them on to the cut down, standard brass to bring the belt width up to spec. Anyone tried this?

 

[HarryN]

I have no experience with using dies to go from one brass design (like basic brass, or .458 win mag, or 375 h/h) to another round.

Would I just cut to length and fire form? Is there a non fire form approach? It would be nice to have a working solution before buying a gun for it.

Thanks

 

[Trickymissfit]

I shoot the .450, and I would not consider it in a hand gun. It's a beast in a rifle, let alone a hand gun. Probably best with an 18' or longer barrel (21" being about right, but a 24" would be perfect). I've first used it with the 350 grain bullet, and a heavy load of 2230. Now trying to get a 400 grain Speer to shoot in it. Nothing wrong with the bullet, but with standing the recoil is the problem. You might make it work with a 16" or 17" barrel. Expect a good dose of carpel tunnel.
gary

 

[gunners]

Why not just do it in 45-70, been round for just about forever. Factory rounds are quite mild so you might stand a chance coping with recoil. Brass supply is good for reloading and load data is plentiful. I've run 350 grainers at 2100fps in my 45-70 before and it's not much fun out of a rifle. Can't imagine running hand gun anywhere near that though maybe cowboy loads would be more enjoyable

 

[Trickymissfit]

Why not just do it in 45-70, been round for just about forever. Factory rounds are quite mild so you might stand a chance coping with recoil. Brass supply is good for reloading and load data is plentiful. I've run 350 grainers at 2100fps in my 45-70 before and it's not much fun out of a rifle. Can't imagine running hand gun anywhere near that though maybe cowboy loads would be more enjoyable

if it were me, I'd go with the .458x2" round, and maybe shorten it to 1.81". Got with a 16" or 17.5" barrel. I'll assume your looking at somekind of a bolt action, and with this your looking at pressures in the 47K psi. The .450 is built around 43K max PSI due to the action constraints (the .450 action is different than the 45-70 action). In a bolt action the .450 ought to be good for 2300fps with a 350 grain bullet. But a major recoil producer.
gary

 

[HarryN]

Some of the constraints:
- I believe (not 100% sure) that in a pistol format, the max barrel length here is 15 inch total, including the brake.
- I am a bit old school, so I like to have an empty chamber until just before firing. I also don't like to fumble around with single shot loading, especially if my heart is going faster than normal.
- The idea is a fixed box fed bolt action, sort of like a 700 adl style loading.

 

[HarryN]

Caliber selection:
- Those are all good suggestions, and I have looked at all of those, as well as the .444, 458 socom, and 450 bushmaster, .44 mag, .445 supermag, .460 SW, etc.
- I haven't dismissed any of them completely, but am more focused on ones designed for magazine fed, bolt action approaches and a good selection of copper bullet options with reasonable BC.
- I like the idea of the .458 x 2 American, or shorter, but if possible, the ability to sometimes buy factory ammo would be nice.

 

[HarryN]

- The most likely bullet is a GS custom 458400HV095 or similar. It is 400 grain (a bit heavier than I want but ok) and has a BC of .374 in the 1600 fps velocity range that I am expecting.
- It is a little bit long, both inside the case and front protrusion, so powder capacity will be reduced from normal. I need to run the numbers in more detail, but I think closer to 35 grains of Norma 200 vs a more typical 40-50 grains. I am still studying the round and running calculations, then I need to run quick load on it.

 

[HarryN]

I used the brake calculator on JE Customs web site for a few variations. With the brake, and some starting point assumptions of velocities in the 1300-1800 fps range, on paper at least, recoil looks not as terrible as it could be.
- I have spoken with a local shop about a .460 SW xvr, which is no slouch, and it appears to muzzle brake pretty effectively. I am hoping that this will as well.

 

[HarryN]

Perhaps coming back to the original question, how is the belt formed on factory belted magnum brass?

I am guessing that it is swaged on after the case is made rather than just bulging it out of the case sidewall, but that is just a guess.

 

[HNDLDR]

Haven't heard of many people messing with the 450 marlin in a long time. Had an coworker give me some once fired brass ten years or so ago. It's still kicking around collecting dust somewhere.

 

[HarryN]

Haven't heard of many people messing with the 450 marlin in a long time. Had an coworker give me some once fired brass ten years or so ago. It's still kicking around collecting dust somewhere.

Maybe everyone else knows better and is waiting to see how long it takes for me to wise up.

I know it isn't the same thing, but it's interesting how my .270 win uses about the same amount of powder as the .450 marlin, but has what appears to be completely different recoil characteristics.

I expected a .458 win mag, with it's much larger powder load to be a beast, but not one person on any forum calls this round "moderate".