450 Marlin chamber with standard belted headspace gauges?

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obiwannabe

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I like the 450 Marlin, but I'm concerned the brass supply may dry up a la 338 Federal. Of course, you can make 338 Fed from other stuff, but with 450 Marlin there are no options.

What would happen if you had Savage pre-fit barrel with a chamber reamed for SAAMI spec 450 Marlin but used standard belted magnum headspace gauges (eg: 300 Win Mag) to install the barrel? The difference in belt width is 0.032"--0.220" for the H&H family vs 0.252" for the 450 Marlin. So the case would end up 0.032" deeper into the chamber in relation to the barrel shoulder.

The follow-up question is: Would that allow me to use cases made from H&H family brass cut back to 2.100"?

If it worked it would be sorta like a 458 American, but 1/10 inch longer with maybe ~3-4gr additional case capacity.
 
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Brass for 338 Federal will never dry up, it's based on the 308 case.

If you want to avoid the .450 Marlin's thicker belt because of fears of brass availability, just chamber your rifle for .458 American and be done with it.
 
That's not likely to work, without encountering extraction issues, if the barrel could even be set back an extra 0.032".
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That was my concern. Maybe not enough room for the bolt to access the case.
 
This is why you should always buy as much brass as you can when you buy anything chambered in something new. However, I'm guessing you can make .450 Marlin out of .416 Remington or .375 H&H. Wouldn't be cheap though.
 
You can't make 450M from anything unless you wanna screw with modifying the belt. That's the problem. They did that on purpose to make sure people had to buy their brand. Just like Apple using a proprietary plug on the iPhone.
 
Those belted cases are intended to headspace (the case to be supported) on the belt. If you reamed the chamber for the wider belt, then a case with a narrow belt would have to headspace on the case mouth (the .450 Marlin has no shoulder). But the real problem would be that a portion of the case ahead of the belt would be unsupported and could blow out.*

You can't just let the case with the narrow belt go deeper into the chamber because then either you are supporting the case on the extractor, which is not good for accuracy, or the case will be too far in for the firing pin to reach it. If you ream the chamber for the narrow belt, the wider belt won't go in all the way and the bolt won't close.

If you are concerned about brass supply, why not just buy a batch now? I don't see that rifle as a plinker, being fired thousands of rounds, but I am obviously not you.

*Contrary to common belief, the belt does not strengthen the case head; it is too far forward to do that. Its original purpose was to support a case with a small shoulder while allowing better feeding than a rimmed case; essentially, it acts like a rim. In most cases today, it is nothing more than a selling point; it evokes the word "magnum".

Jim
 
The 450M belt is not "wider", it's LONGER.

The 450M and H&H family belts are both 0.532" wide. The 450M belt extends 0.032" further up the case body. The case dimensions above the belt are also the same.
 
useless smith

I had exactly the same worries about brass availability especially in the UK but also incase of problems when hunting in Africa etc. I figured that you could cobble together something workable from any gunshop in the world if you use standard belted mag brass and a 2.1" case length. So I asked my smith to set headspace for mag brass instead of marlin. Unfortunately he didn't listen and used marlin saying that it was working with both. It's back with him getting sorted as it is only firing 3/10 tries even with marlin brass. First and last job he does for me! :mad:
 
Heads space, head space etc. Then there is the belt, I would suggest cutting the belt back on the 450 Marlin case. I would have no problem reaming a mag chamber without the belt, but, that would be on cases with shoulders. A magnum chamber without the belt would be easier on the reloader when the reloader tries to set both the belt and shoulder to contact at the same time.

F. Guffey
 
The reason for the thick belt on the 450 Marlin is not some proprietary cartridge thing (wouldn't make sense as Marlin doesn't manufacture cartridges) but fear that someone could stuff a 450 Marlin into any H&H belt based rifle. With the right bullet the cartridge is short enough to fit even into a 300 H&H, but due to the thick belt the bolt won't close on the cartridge extending out the end of the chamber.
 
What would happen if you had Savage pre-fit barrel with a chamber reamed for SAAMI spec 450 Marlin but used standard belted magnum headspace gauges (eg: 300 Win Mag) to install the barrel? The difference in belt width is 0.032"--0.220" for the H&H family vs 0.252" for the 450 Marlin. So the case would end up 0.032" deeper into the chamber in relation to the barrel shoulder.
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This seems backwards to me.

As I understand it, the 450 Marlin belt is taller than a normal Magnum belt. So if you screwed in a Savage barrel until it stopped on a normal Magnum headspace gauge it you would screwing it in farther than you would for a 450 Marlin gauge. You'd end up with .032" less headspace. This would not allow you to chamber a 450 Marlin because it was specifically designed not to chamber in normal magnum chamber.

Either buy a lot of 450 Marlin brass or chamber the gun in 458x2 and make your brass from 458 WM.
 
Hmmm. Now we have the Marlin belt being "wider" (me), "longer" (obiwannabe) and "taller" (natman). I think "wider" is the correct term.

The Wikipedia article says, "Visually, the case resembles that of the .458 Winchester Magnum with a wider belt." (Italics mine)

When I order a belt (as in the holding pants up kind) I like it 1 1/2 inches wide, not 1 1/2 inches long or 1 1/2 inches tall.

Jim
 
Okay. So we're talking about the same thing. The word "wider" made me think of an increased cross-section rather than on the longitudinal axis of the case.

I would agree with your points above if I were trying to stick a 458x2 case into a weapon set up for 450M--obvious head space issues. But I'm talking about resetting the head space to match the narrower belt. Head space changes are a snap with a Savage--just screw the barrel in further. I'm just not sure if I can close a gap of 0.032" before the front of the locking lugs touch rear face of the barrel.
 
Do you have a Savage barrel of some sort? Do you know somebody with a Savage barrel? Doesn't matter what caliber.

I'll see if I can find my takeoff .308.

Drop in a case or gauge and measure the protrusion. Then consider whether you can screw the barrel in enough farther before the barrel hits the bolt head.
 
I'm just not sure if I can close a gap of 0.032" before the front of the locking lugs touch rear face of the barrel.
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You would know if you measured case head protrusion and the distance from the seating surface to the bolt face. Then there are barrels that are counter board like the ring around the ring around the ring.

You are not going to believe this, an individual wanted to do all the thinking and he had this bad habit of correcting everything said. He wanted to know the length of a pole and instructed someone to measure. It was not long before he had the answer.

When he saw the pole he was livid, seems the pole was standing when he wanted it measured, the individual measuring the pole cut it down. For the sake of correctness if he wanted to know the length of the pole he should have asked someone to measure the height or to check to see how tall the pole was.

F. Guffey
 
Do you have a Savage barrel of some sort? Do you know somebody with a Savage barrel? Doesn't matter what caliber.

Drop in a case or gauge and measure the protrusion. Then consider whether you can screw the barrel in enough farther before the barrel hits the bolt head.
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I have many Savage barrels but none in a belted cartridge. I'm not sure if the measurement would correlate because the 30-06 family cases have different rim/head dimensions, but it's a simple enough thing to try, I guess.
 
Well I don't think it'll work. If you assume the case sits in the chamber all the way to the base of the belt then there's only about 0.133" exposed. the Savage bolt recess is 0.135" so there's no room at all for a different head spacing without machining off some of the breach end of the barrel.

I bought a set of 450 Marlin dies to play with on some range pick-up 300WM brass and it really doesn't work too well. Hornady's 450M brass must be fairly thin to allow for a .458" bullet to seat 0.5" or more into the case. 300WM brass is pretty thick in comparison and would need considerable reaming to accept the bullet and still fit a 450M chamber.

I think I'll just go 458x2" for this project.
 
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