Khaki Posted 11 January , 2013 Share Posted 11 January , 2013 Purely for my own interest what makes the Great War rimmed cartridges almost obsolete compared to the rimless? is it ease of manufacturing of the cartridge or the rifle extractor etc etc? I understand that rimmed continued for many decades but surely rimless won out. thoughts? khaki Link to comment Share on other sites More sharing options...
dman Posted 11 January , 2013 Share Posted 11 January , 2013 Rimmed cartridges, where rim protrudes from base of the cartridge, use the rim to position the round and give the extractor something to grab onto The rimmed cartridge is the oldest of the types and has a rim that is significantly larger in diameter than the base of the cartridge. Rimmed cartridges use the rim to hold the cartridge in the chamber of the firearm, with the rim serving to hold the cartridge at the proper depth in the chamber—this function is called "headspacing". Because the rimmed cartridge headspaces on the rim, the case length is of less importance than rimless cartridges. This allows some firearms chambered for similar rimmed cartridges to safely chamber and fire shorter cartridges, such as using .38 Special cartridges in a .357 Magnum revolver. Rimmed cartridges are well suited to certain types of actions, such as revolvers, where the rim helps hold the cartridge in position, and break-open single shot firearms. Rimmed cartridges generally do not work as well in firearms that feed from a box magazine. Some types of rimmed cartridges, the rimfires, also use the rim to contain the priming compound used to ignite the cartridge. Rimmed cartridges have problems in a box magazine where the rims of the stacked cartridges can become entagled and cause a feed jam For this reason Squadies were taught to make sure that the rims of the carridges were properly aligned Link to comment Share on other sites More sharing options...
Dan Brock Posted 11 January , 2013 Share Posted 11 January , 2013 Didn't want to have a "rim-over-rim-stoppage" do we. There was an entirely different scheme to loading the Mosin Nagant chargers. Were there any rimmed rounds in the GW other than those two and the Lebel? Link to comment Share on other sites More sharing options...
4thGordons Posted 11 January , 2013 Share Posted 11 January , 2013 AustroHungarian 8x50R? Link to comment Share on other sites More sharing options...
TonyE Posted 11 January , 2013 Share Posted 11 January , 2013 Yes to that Chris, plus the Roumanian 6.5mm Mannlicher. (and the 13mm T-gewehr, although that was single shot) The Japanese 6.5x50SR Arisaka (.256 inch in British service) was a semi-rimmed compromise. Ironically, the father of the .303 round, the 7.5mm Swiss Rubin, was rimless but the British military took a concious decision to change it to a rimmed round as they believed this was a better solution for machine guns. The great advantage of a rimmed round for military purposes was that because the case headspaces on the rim the weapon chamber can be made to much less fine tolerances, allowing for differences in ammunition under wartime conditions, Both the SMLE and the Mosin Nagant took advantage of this to increase overall reliability. With a rimless round which headspaces on the shoulder the chamber must be much more precise. To further answer Khaki's original question, it is not ease of manufacture as rimless cartridges are made as rimmed rounds and the rim is then turned off. It is mainly to do with feed mechanisms. Apart from the problems of "rim over rim" stoppages in box magazines, rimmed cartrdiges can only be used in belted machine guns in "pull out" designs like the Vickers. This complicates the gun action compared to modern "push through" designs. Picture shows the evolution of the .303 inch round. L. to R. Swiss made 7.5mm Rubin from British 1886 trials British .303 Rubin from 1888 Troop Trials .303 inch Powder Mark I as introduced in 1889. Regards TonyE Link to comment Share on other sites More sharing options...
Stoppage Drill Posted 11 January , 2013 Share Posted 11 January , 2013 of the firearm, with the rim serving to hold the cartridge at the proper depth in the chamber—this function is called "headspacing". I think you need to have another look at what headspacing is. Link to comment Share on other sites More sharing options...
MikB Posted 11 January , 2013 Share Posted 11 January , 2013 With a rimless round which headspaces on the shoulder the chamber must be much more precise. Regards TonyE The rimless cartridge case, too, must be made to closer tolerances between shoulder and casehead. I've never had a rim-over-rim stoppage in a Lee-Enfield, neither has anyone I know of - and I've only heard of them secondhand in Bren guns. Regards, MikB Link to comment Share on other sites More sharing options...
MikB Posted 11 January , 2013 Share Posted 11 January , 2013 I think you need to have another look at what headspacing is. Why? What he said seems correct to me. Regards, MikB Link to comment Share on other sites More sharing options...
4thGordons Posted 11 January , 2013 Share Posted 11 January , 2013 Why? What he said seems correct to me. Regards, MikB Is "Wikipedia" a he ? Link to comment Share on other sites More sharing options...
Dave1418 Posted 11 January , 2013 Share Posted 11 January , 2013 Hi dman. I have to disagree with you, the rimmed may be the earliest type of metal cartridge but the cartridge for the Von Dryser needle gun beats it by a good few years. It being the first self contained cartridge containing powder, primer cap and ball in one cartridge. The primer cap being situated between the powder and the bullet so the needle had to pass through the propellent first to hit the primer. :-) regards Dave Link to comment Share on other sites More sharing options...
MikB Posted 11 January , 2013 Share Posted 11 January , 2013 Is "Wikipedia" a he ? Well, so what if dman pulled it from there? How does pointing out the source advance the debate, if there is one? There are a number of points in the linked entry that could be disputed, but the statement that the rim on a rimmed round governs headspace from the cartridge point of view isn't obviously one of 'em. The shoulder of the chamber in a 303 can be 1/16" or more in front of the shoulder on a new case without risk of rupture on first firing, and I don't think you'd get away with that in a contemporary necked rimless round like 7,92x57 or 30-06. Regards, MikB Link to comment Share on other sites More sharing options...
4thGordons Posted 12 January , 2013 Share Posted 12 January , 2013 Well, so what if dman pulled it from there? How does pointing out the source advance the debate, if there is one? There are a number of points in the linked entry that could be disputed, but the statement that the rim on a rimmed round governs headspace from the cartridge point of view isn't obviously one of 'em. The shoulder of the chamber in a 303 can be 1/16" or more in front of the shoulder on a new case without risk of rupture on first firing, and I don't think you'd get away with that in a contemporary necked rimless round like 7,92x57 or 30-06. Regards, MikB It simply indicates the source of the "errors" (if they exist) that's all. As you specified "HE seems correct" in response to Stoppage Drill's suggestion that [dman] needs to check the definition of headspace (ie "He" was mistaken). Perhaps it is my day job coming through, where wholesale posting of information assembled by others without crediting them or noting the source is usually frowned upon. As far as I am concerned there is not a debate here. I agree with the observations you made and I have never in 20+ years of shooting .303" with some regularity ever expereinced a "rim over stoppage" -- something I believe we have been round and round on before. Chris Link to comment Share on other sites More sharing options...
TonyE Posted 12 January , 2013 Share Posted 12 January , 2013 ......... something I believe we have been round and round on before. Chris Subtle, young Chris, very subtle! Cheers Tony Link to comment Share on other sites More sharing options...
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