I would like to make a lengthened .450 Marlin case beyond the current 2.1" size. However, there isn't anything with the same belt length made. Would it be possible to fireform normal magnum cases to get the extra-length belt? I'm not very positive about this idea, but read that it had been done in the past.

quote:

Would it be possible to fireform normal magnum cases to get the extra-length belt?

Wouldn't think so. Set the barrel back or start with a new barrel and cut the .03" shorter belt. Then using most any H&H based magnum case.

No you can't fireform anything to that, safely,
and end up with a safe belt. If you put pressure up
to where the brass ahead of the belt on a 458WIN
case tries to make a new belt you'd have an inside
corner that is stretched and may not be safe.
And you'd have to do it in super strong bolt gun.....

If you have a 450 Marlin and want a 458 Win equivalent maybe
just set barrel back 1 or 2 even threads if you have barrel
sights and if no sights the exact amount.And use 458Win cases.Ed

The whole idea of the different belt on 450 Marlin brass was to "stop" people doing this

But I wish you the best of luck

regards
S&F

Thanks guys. As I said above, I was leery of it, but stranger things have come about. The problem is I have a Browning BLR that changing barrels or even setting one back is next to impossible. Been rejected by three very competent gunsmiths. Guess I'll just have to piddle along with the shorter case and seat the bullets out as long as I can while still maintaining sufficient neck tension.

Running a 300 RCM reamer in there would be tempting.
I would ask a gunsmith to see if a metal
Spacer washer to the chamber could help.

quote:

Running a 300 RCM

Then headspace on???

You could have two 15 thou shoulders 30 thou total. Use 416 Ruger brass to form
A longer case to say 2.3"

quote:

You could have two 15 thou shoulders 30 thou total

Ok make a bottle neck out of it.

Hey Boom your memory is probably better than mine. Didn't Bent Fossdal use 06 cylinder brass run it in a 240Wby die and form a belt?

If that was what he did couldn't you take a 416Ruger case and do the same thing in a 450Marlin die? Haven't checked all the dimension but the question was really just forming a belt.

Belt scraping is one idea but a pain in the ass to make I bet.
Quality cartridge made the brass for Bent.
I like a 2.25" ruger case idea better.

quote:

Originally posted by boom stick:
Belt scraping is one idea but a pain in the ass to make I bet.
Quality cartridge made the brass for Bent.
I like a 2.25" ruger case idea better.

Good Idea, the ruger case will clean out the old belt and 2 small shoulders could be used to head space off

The case is slightly wider at 2.25 so the shoulders should be easier to head space off.

regards
S&F

quote:

Good Idea, the ruger case will clean out the old belt and 2 small shoulders could be used to head space off

I agree sounds like a great idea BUT. If no one will set the barrel back or swap the barrel out on his BLR can he get the barrel pulled so the chamber can be recut?

If it's a take down he can rechamber by hand tool.

quote:

If it's a take down he can rechamber by hand tool.

Yep I agree with that one I think (haven't looked at a take down for a number of years and have slept several times since then.

MIGHT could either form long marlin out of rum cases.. or solder on a neck extention to a marlin case...

or buy a custom run of brass...

or, do what the rest of us would do.. load TSX bullets longer, and not bother with altering the case

Belting the Ruger brass for a proprietary case is interesting. Costly but interesting. If that were the "case" then a 2.4" version for a kind of Lott Winmag thing. I like a 2.25" Ruger case idea better. Have a long .6" neck length. Figure 80 grains capacity so use 45-70 load data and 450 Marlin load data for starting points. Figure max loads of 400@ 2100

So many good ideas.
Have already seated bullets out as far as I could and still get sufficient neck tension to hold them. That helped some, but not enough to allow forward seating as much as is available in the magazine. Modified the magazine's front spacer to allow the longer cartridges to fit in that. Had the throat lengthened to allow heavier bullets.

Am using both Hornady .458 325gr LeverRevolution pointy bullets and Barnes (don't hate me Michael) 300gr SOCOM bullets for the lightweights. They could use the longer case for sure.

Final thought on modification is, as I've commented before in another thread, run a WSM reamer in and get a little over 80 grains case capacity.

My chronograph has gone tits-up so don't have velocities yet. Loads have been over book with three different powders using the maximum OALs. No pressure signs, or excessive expansion at the case head.

Still waiting for my scope to come in. Leupold VX-R 1.25-4x with the post/circle/red dot. Backordered I've been told.
Max