Quick Question: why is there a belt on Belted magnum

Discussion in 'Handloading and Reloading' started by Mark_Mark, Jan 26, 2022.

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  1. Walkalong

    Walkalong Moderator Staff Member

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    True, we can't change mechanical headspace built into the firearm by sizing cases, but we size brass to fit our chamber to limit head clearance. We often call it headspacing though. Search posts by @fguffey
     
  2. Mark_Mark

    Mark_Mark Member

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    you can bump the belt? sounds hard
     
  3. DM~

    DM~ Member

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    No, but there use to be dies to add a belt to 30-06 brass, by scraping enough of it from the sides of the case to "make a belt".

    Those cases were then turned into .240 Wby. cases, which is basically, a 6mm - 06 with a belt.

    DM
     
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  4. redcon1

    redcon1 Member

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    This is a constant source of confusion on the internet-headspace versus cartridge headspace clearance versus head clearance now. There needs to be one well recognized and understood term and that term needs to be agreed upon by everyone IMO.
     
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  5. South Prairie Jim

    South Prairie Jim Member

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    I miss him.
     
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  6. redcon1

    redcon1 Member

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    Back during the #44 panic, I started reloading for 300 win mag. I had owned a Sendero in 300 WM for a decade that I hadn't done anything with and I wanted to shoot it but you couldn't find 300 win mag brass anywhere. I got my hands on everything I needed except brass. It was around this time that the military started using 300 WM so surplus brass was available and I got my hands on 200 pieces of that finally. The problem was, it had all been fired out of different rifles (presumably only one time although I don't know that for sure). Some of these cases could be full length resized to fit my rifle, some (most) could not because the cases had all expanded forward of the belt and the sizing die couldn't reach it because of the belt. I purchased the $100 LW die and managed to beat a couple of them down enough to chamber but not all of them by any means. It was at that time that I swore off belted cartridges. that belt serves no good purpose and it made these cases unreloadable. I ended up having to buy factory ammunition which I shot out of my rifle and then had no problems with. To make it all worse, the chamber of my rifle has a pit that "stamps" every case so that barrel has to go, my 300 WM reloading dies are oiled up and put in the back of the shelf where they will likely never be used again unless to sell or trade and I have dreams of a 30 Nosler barrel floating around in my head. It was a somewhat expensive and time consuming lesson. the project was deemed a failure. I'll never own another belted cartridge under any circumstances. if you gave me one, I'd sell it.
     
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  7. redcon1

    redcon1 Member

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    I've probably read a thousand of his posts. I probably understood 500 of them. :)
     
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  8. Ru4real

    Ru4real Member

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    Wow. Was the belt was added for head spacing reasons? No!

    The belt was added to reinforce the base of the case which might not be sufficiently supported due to manufacturing tolerances and bolt design variations. (A good idea in theory)

    One additional feature was to change head spacing for magnum calibers to the front of the belt. (A bad idea in theory)

    Do modern guns need a belt for “magnum” calibers. Absolutely not.

    Did guns with 1950’s manufacturing techniques need the belt? Debatable.
    Was it a marketing ploy to add the belt? Debatable.

    Is it possible to change headspace from the belt to the shoulder? Yes, and I always do. My reloads may not work in your gun, That’s why they are mine. No, you cannot have any.

    But I will tell you how to make your belted magnum more accurate by headspacing on the shoulder, because we are all friends here. :)
     
    Last edited: Jan 26, 2022
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  9. Mark_Mark

    Mark_Mark Member

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    Ok… didn’t know their was so many contradictions and lure over the Belted case!
     
  10. DM~

    DM~ Member

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    I don't see the problem!

    You buy factory ammo, and fire it in YOUR chamber. IF you want to reload the cases, then size the case so your rifle just closes on the sized case, and then finish loading it!

    SAME as you would for any other case with a shoulder.

    DM
     
  11. South Prairie Jim

    South Prairie Jim Member

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    Guffy has a special way of making me feel like an Idiot.. but he darn sure made me think about what I was trying to do.
    He once told me that I may not be cut out to be a reloader.
    I had to agree…..:oops:
     
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  12. Mark_Mark

    Mark_Mark Member

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    Sounds like a cool guy!
     
  13. jmorris

    jmorris Member

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    And then there’s this…

    49DA8067-2181-402A-A03A-BA126DE20662.jpeg
     
  14. Mark_Mark

    Mark_Mark Member

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    now that’s cool! whatcha got there?
     
  15. jmorris

    jmorris Member

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    The one on the left is a 45-70, that in some rifles can be loaded to the point it is dangerous for antique firearms chambered in the same caliber, with a substantial gain in performance.

    The one on the right is a the 450 Marlin, designed to give 45-70 “Marlin” loads to people that don’t reload because, other that boutique loads, the 45-70 is loaded to pressures that are safe in old trapdoor actions.

    In other words it’s factory ammunition that isn’t backwards compatible to another that has a lower operating pressure.
     
  16. HowieG

    HowieG Member

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    The main reason British Magnum hunting cartridges were more sedate back in the day is that they were loaded with cordite, and they were used in the hottest places in Africa, which were basically the hottest places on earth. The ammo was temperature sensitive and anybody shooting at something that bites darned well wanted to ensure that the empty could be ejected, and a new round chambered without any hitches. It is the same reason that the British liked those long sloping shoulders.
     
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  17. Mark_Mark

    Mark_Mark Member

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    ok, That make a ton of sense! I’ve never bought factory 45/70 and I load to shoulder hurting pressures but for a Ruger #1. And that load I would never shoot in my Pedersoli 86/71, I just don’t want to break something.

    450 Marlin, the belt was put there so people can’t load it in a Trapdoor?
     
    Last edited: Jan 27, 2022
  18. Mark_Mark

    Mark_Mark Member

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    those imperialist British thought of everything. I wish the British and Japanese would have done more firearms and cartridge development. Just imagine the ideas they would have produced.
     
  19. Walkalong

    Walkalong Moderator Staff Member

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    Can't........load it in a Trapdoor.
     
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  20. tightgroup tiger

    tightgroup tiger Member

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    Not sure anyone but you, me, and south prairie jim, and Walkalong, got your joke.
     
  21. jmorris

    jmorris Member

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    Yes, the 450 Marlin can’t do anything the 45-70 can’t, except not be chambered in 45-70’s.

    It no more a “Magnum” than these loads are https://www.buffalobore.com/index.php?l=product_list&c=35

    But one would be ill advised to shoot those in an antique action and the 450 Marlin simply won’t fit.
     
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  22. Slamfire

    Slamfire Member

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    That was true of all the proprietary British big game cartridges. The British were smart to keep their cartridges at 40 kpsia. Derived from British proof standards, the .470 Nitro Express (NE) has a maximum average pressure (MAP) assignment on SAAMI equipment of only 41,000 psi. American's wanted horsepower, and to get the performance they want, the .458 Win. Mag. has a MAP of 60,000 psi. I have read on other forums the propensity of factory 458 Win Mag cartridges to stick during African hunts. Winchester wanted to shoe horn a big bore, high performance cartridge in a 30-06 action, and the only way to get the velocities they wanted, was to go high pressure. The higher the pressure, the less margin for error. The British custom of increasing the cartridge capacity, to get those velocities at low pressure, is simply the better way to go.

    I also believe there can be another cause for extraction difficulties, and that is the shooting community thinks ammunition/gunpowder is immortal, unchanging, pristine throughout eternity. Gunpowder is not immortal, pristine, unchanging, gunpowder pressures rise with age, and the stuff has an unpredictable shelf life. Eley guarantees function of their match rimfire for 10 years, and match winning capability for around five. They don't guarantee function for 20 years, or 40 years, or longer. Combined with the propensity of shooters to hoard expensive ammunition for decades, that may be the reason for the "caking" of power in 458 Win Mag cartridges in this thread:

    Why I No Longer Defend The .458 Winchester Magnum
    https://www.africahunting.com/threads/why-i-no-longer-defend-the-458-winchester-magnum.17615/

    I think what they are seeing is evidence of powder deterioration, such as these individuals experienced:

    OSW5VUq.jpg

    old IMR powder, some of it turned "gummy"

    jcVJHTu.jpg
    cQNEBa1.jpg
    x1vTyG5.jpg

    An individual who buys African cartridges, at $70.00 a box of 20, is unlikely to shoot all of it up busting cans. And then because shooters have been taught that gunpowder lasts forever, unfired rounds will sit around for decades. I think it highly probable some decades old, high pressure American ammunition made its way to Africa, and given that the cartridge originally was a 60+ kpsia round, now the deterioration, and heat, rounds could be producing 90 kpsia in the field. Maybe even more!

    Regardless of how it is defended, there is no up side to ignorance.
     
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  23. Mark_Mark

    Mark_Mark Member

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    45/70 is a beast
     
  24. Mark_Mark

    Mark_Mark Member

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    reminds me of a stack of batteries melting
     
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  25. Jackiesman

    Jackiesman Member

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    I had repeated case head separation in my 375 H&H until I stopped neck sizing and went back to full length sizing which seemed to solve the problem. Now I get 6-8 reloads from my cartridges. Never had a problem with jamming as a result of bullets shifting in the magazine of my Weatherby, and I load 235 grain bullets for elk hunting. But I have only had two or three occasions where I had to have quick follow up shots, so I can’t say it won’t happen.
     
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