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What does "belted" mean?

cmummacmumma Member Posts: 25 ✭✭
edited April 2003 in Ask the Experts
What does "belted" mean when referring to cartridges (like the .300 Winchester Magnum and the 7mm Remington Magnum)? Thanks.

Comments

  • rocktonrockton Member Posts: 551 ✭✭✭
    edited November -1
    Refers to the raised area,belt, located on the primer end of the cartridge. It is used for head spacing and serves no useful purpose except to look a little different.

    Rockton
  • cmummacmumma Member Posts: 25 ✭✭
    edited November -1
  • 22WRF22WRF Member Posts: 3,385
    edited November -1
    A picture worth a 1000 words
    belted.jpg

    Snake.gif
    underwaysm.gif
    SOLD MY COW SO I DON'T NEED YOUR BULL
    A Grumpy Old Man
  • JustCJustC Member, Moderator Posts: 16,035 ******
    edited November -1
    It strengthens the case head, which is where the belt is located. Once the primer is struck, and the powder consequently ignited, the expanding case fills the dimension of the chamber, increasing pressures. The case head, pressed against the bolt face, bears the pressure of the rearward force, and is the area in which most of the brass flow, toward the front, is initaited. That strength was, other than headspacing, introduced to hopefully avoid a case-head seperation, which is probably the second worst accident that can happen in the chamber,....preceeded by firing a larger caliber into the bore which is too small to accept the bullet. In either case, extremely hot gasses and brass particles are forced rearward toward the shooter. That hole in the side of the action is to help alleviate pressure and gasses, should this situation occur,...but it isn't failsafe, the shooter still suffers. Measure you case head thickness if you are reloading for a magnum, or any other caliber. Once it gets too thin, throw the brass away!!!!!

    why chase the game when the bullet can get em from here?....
    Got Balistics?
  • 11echo11echo Member Posts: 1,001 ✭✭✭✭
    edited November -1
    A belted case, as already pointed out, is for head spacing the cartridge. As I recall this is a concept originally use for the 300H&H, a British design. If you'll look at Mr. 22WRF's pic.s you can see how most cartridges are either head spaced on the shoulder or the rim. On the 300H&H cartridge has a long case with hardly any shoulder and the rimmed case is a older design, so Holland & Holland coughed up this belted design, as a point to index the cartridge. With all do respect, it is not put on the cartridge for strength. My 2 cents ...Mark


    "FEAR the Goverment, that fears your ARMS"
  • He DogHe Dog Member Posts: 48,506 ✭✭✭
    edited November -1
    I will have to agree with JustC. While I have no way to test the additional strength added by that little belt, note that it is only used on magnum cartridges. While it may indeed have first been used for headspaceing and continues to be used for that purpose, the belted cartridge trend in the last half of the last century was to used belted cartridges for "magnum" loads. Whether it worked or was just a marketing gimmick is anybodies guess, but note also that that one of the major changes touted for the currently trendy short magnums is that they are not belted.
  • JustCJustC Member, Moderator Posts: 16,035 ******
    edited November -1
    I wondered when the new magnum issue would arise[:D]

    Note the case used to create the new short mags and ultra mags,.....the 404 jeffrey. Now, saw the belted case in half, then saw a 404 jeffrey in half, and you will quickly see the difference, as well as gain an understanding of why the belted mags, are belted. The 404 jeffrey case is much thicker, hence the strength and no need for a belt.If headspacing was the only issue, they would headspace off the shoulder, just like everything else. The brass and rifle steel strength back when the belts were invented, was wayyy under the strength, uniformity, and precision that we have today. By headspacing off of the belt, you allow a slight "surge" in the case, to meet the chamber shoulder, and the bullet release is at the same time, therefore, no excessive pressure spike and consequently, no blown up rifle. That's why when you ask any gunsmith with benchrest knowledge, how he would build you a belted magnum chamber, he would tell you that first and foremost, he would cut it to headspace from the shoulder, and not the belt. Factory chambers are a mute point as SAAMI specs call for oversized chambers and undersized factory ammunition,....just another accuracy detterent that you can thank all the lawyers for[:(!]

    Keep in mind, once a fired case is neck sized, (and re-inserted in the same rifle) it is headspacing from the shoulder, which is proven to be a more accurate loading technique, all other things being equal.
    However, since no two chambers are the exact same size, all factory ammo is made small enough to fit any rifle, without dangerous pressure spikes upon ignition in a small or "tight" chamber.

    yes, H&H may have had a different initial idea, but as is the way of any industry, other companies take your idea, and experiment on it to create new avenues for performance in a product they can offer. The belt was found to increase the web strength, and the belted magnums were "born by fire", all punn intended. Also, the industry, when creating new calibers etc, will often use a "parent" cartridge. The parent cartridge in this case, being the belted H&H case, which would have made it a necessity to re-tool existing machines and dies to cut the chambers and form the cases for the new calibers, without the belt. That would eat into the profit they expected from the new calibers, and therefore, it was left alone for yet another reason. Notice the only new magnums invented since the belted magnums,....have been the cases based on the 404 jeffrey and 416 rigby, which have much thicker brass at the case head and web area, due to thier original design purpose of pushing 300-500grain bullets with a powder charge in the 120gr range. that kind of punishment requires brass that will sustain that intial pressure boost, while not rupturing. they made the perfect case for the new supermagnums with no belt and with which to headspace from the shoulder. AND, it only took 100yrs to figure that out.[;)]

    why chase the game when the bullet can get em from here?....
    Got Balistics?
  • 11echo11echo Member Posts: 1,001 ✭✭✭✭
    edited November -1
    I'd like to submit a link to a reloading die maker. Please look at question number 24 frist, then read the other questions ...very enlightening!! ...Mark

    http://www.larrywillis.com/answers.html

    "FEAR the Goverment, that fears your ARMS"<br>
  • JustCJustC Member, Moderator Posts: 16,035 ******
    edited November -1
    He may have made some headway on me until he threw this one out there.....

    27. Why not switch to one of the new unbelted magnums?

    Some of the new unbelted magnum cartridges might be pretty good. However, many of them are loaded to extremely high pressure so that they can compete with the performance of existing belted magnums. Some of these cartridges are loaded hot enough to cause visible damage to the throat after firing very few rounds. They usually reduce magazine capacity and it is very common with the short unbelted magnums to have fired cases stick in the chamber, causing difficult case extraction. Some of these new unbelted magnums might become popular while others will disappear forever.


    So, The new non-belted magnums are faulty? That's funny,..because all of the benchrest shooters I have talked to who have switched over to the short mags state they are inherently more accurate (off topic but worth stating) and I have yet to hear a single person tell me they have ever had a case stick in the chamber, And let's be real,...the benchrest shooters are the ones who pretty much invent the new cartridges that make it to the market, as well as shoot these cartridges in the closest tolerance, tightest chambers, in the world. No chamber specs out to the tolerances of a well built benchrest rifle, even if it is a 1000yd+ bench gun.

    Also, what is this business about burning a throat, or showing noticeable erosion in only a few rounds? Not even the 30-378 weatherby (the epitome of over-bore) eats a throat after only a few firings,....and the RUM's are several hundred fps behind that loading. I know of 300rum's on thier 1200th round with NO signs of accuracy degradation thus far.

    4. I've heard that it is best to headspace on the shoulder and not on the belt. Is that true?

    Yes. If you headspace on the belt, the shoulder of your case will have to be blown forward against the shoulder of your chamber, when fired. This will stretch your brass and can cause case separations.


    So, if you don't use his die your case head will seperate? I called and asked the rangemaster for our local police dept, who is also a benchrest competitor and past winner at Quantico, about how many times his brass in the Stolle actioned, 300wthby he uses for competition has seperated,....it hasn't.

    Not to take away from his idea, or his product,...maybe it is in it's infancy and will dominate the circuit,...but I will remain skeptical and stick with my original conclusion.

    I mean no disrespect 11echo, and wish not to insult your research, I just come from a different school of thought and have trouble with some of the theories listed on that page.

    As for the belt,..I will concede that the jury is still out.




    why chase the game when the bullet can get em from here?....
    Got Balistics?
  • Tailgunner1954Tailgunner1954 Member Posts: 7,815
    edited November -1
    quote:Originally posted by 11echo
    I'd like to submit a link to a reloading die maker. Please look at question number 24 frist, then read the other questions ...very enlightening!! ...Mark

    http://www.larrywillis.com/answers.html

    "FEAR the Goverment, that fears your ARMS"<br>

    I've seen Larry Willis, and his die, chewed up and spit out on every board that has experanced "belted mag" reloaders on it.
    The only people with a possable need for it, are those with defective chambers. Bottom line is that his die is just another un-needed gimmick for the newbie "belted magnum" reloader to waste his money on.

    Some guys like a mag full of lead, I still prefer one round to the head.
  • 11echo11echo Member Posts: 1,001 ✭✭✭✭
    edited November -1
    Just a quick note here. I'm only "spouting" what I've read. I personally only owned one belted mag. and that was a 300 weatherby. (Great weapon by the way!) But I don't like "sharp" recoil and normal don't load my cartridges on the "hot" side. Mr. JustC I take no disrespect here, we're just two old gun nuts swapping stores around the cracker barrel here! *G* My best wishes to you. ...Mark(11echo)


    "FEAR the Goverment, that fears your ARMS"
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