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Brass life expectancy ? |
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hoadie 
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Joined: March 16 2006 Location: Niagara/Canada Status: Offline Points: 9680 |
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 Posted: November 20 2013 at 10:00am |
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How do you guys remember all this stuff? You wear ear plugs so it don't leak out at night?
 Man-reading this stuff is like cramming fer an exam! Hoadie |
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Loose wimmen tightened here
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A square 10
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Posted: November 20 2013 at 10:39am |
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was thinking the same thing hoadie , i would need all this written down - oh yea , it is , right here
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SW28fan
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Posted: November 20 2013 at 11:12am |
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I thought that I was OCD and I work as an engineering technician in the research and development department of a company that makes equipment for brain surgery.
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Have a Nice Day
If already having a nice day please disregard |
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LE Owner
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Joined: December 04 2009 Status: Offline Points: 1047 |
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Posted: November 20 2013 at 11:19am |
and you missed the point that "smaller in relation to" does not equate "undersized". The Military cases that are at the broad end of manufacturers tolerances are a closer fit to chambers cut at the broad end of manufacturers tolerances, that's true enough, but that does not mean that cartridge cases manufactured to the middle range of the manufacturers tolerances are "undersized" cases. These cases are going to fit any chamber that is cut to minimum specs or greater, that's why they have both minimum and maximum measurements based on reference dimensions and allowable +/- tolerances. If you can show me any document mandating that cartridge cases that fit within the minimum case sizes as quoted by SAAMI would be turned down by British inspectors as too small then do so. On the other hand the RAF made absolutely sure that no cartridges they used were beyond the maximum specification, because far to much of WW1 production military ball did exceed maximum specifications to the point that not even a generous chamber would insure the cartridge would chamber. The .303 originally used a compressed black powder charge, with all the fouling problems of any black powder era repeating rifle, so the chambers were always cut to allow for fouling and dirty cartridges. This amount of slack was more than enough for use with the cleaner burning cordite cartridge so long as the cartridge case was not so fat as to negate the built in clearances. It was only when WW1 wartime production and subcontracting from suppliers who had never before made such long runs on the order of hundereds of millions of cartridges per contract that worn machinery produced excessively thick rims, out of the round or off center rims, shoulders too far forwards to allow chambering in all but the loosest chamber and cases so fat the soldier had to effectively size down the case by means of the bolt if he could even close the bolt far enough. Add to that the sandy European loam (60% Quartz sand with average granule size of .006) and the thicker the rim and broader the case the less clearance in the chamber. The sandy loam also contributed to wear of the chambers. When dust and sand get into the chamber between case and chamber wall the expansion of the case drives the granules into the brass and into the steel chamber wall. When extracted that sand cuts away at the chamber wall. When sand and dust get into the fibers of the cleaning cord and patch material every pass wears away at bore and chamber. The effect of annealed iron wire gauze speaks for its self. Extraction can take place thousands of times and passes with the pull through cord would also be on the order of thousands. Wear builds so long as the rifle is in service and sooner or later takes its toll. If you start off with an already generous clearance , then increase that clearance to allow for out of specification cartridges, and that already near maximum chamber suffers wear from the rough cleaning methods of the day, then its the chamber that's over sized for the cartridge not the other way around. PS Those grossly out of spec cartridges were not due to any official increase in acceptable dimensions, it was due to British inspectors allowing crappy ammo to pass then palming it off on their allies whenever possible. The French caught on quick and began pulling bullets and charges from British supplied .303 ammo for the Lewis gun they used on their aircraft and basically remanufactured it , culling the worst cases and bullets, and inspected each cartridge to a much higher standard.
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LE Owner
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Posted: November 20 2013 at 11:32am |
Well the opposition can make shorter posts because they rely on flat blanket statements that look good on the surface but in actuality make no bloody sense. Partly that is due to contrarianism , they want to debunk conventional wisdom by substituting their own value system. To them headspace is a "myth" or of no importance and manufacturers tolerances mean nothing. I've even seen people claiming that accuracy and penetration is of no real importance in an infantry rifle, where they got that I'll never know. There are texts on cartridge manufacture available online. These are worth reading. I'm certainly no expert but I at least know the basics.
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MaxP
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Joined: March 21 2013 Location: Australia Status: Offline Points: 184 |
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Posted: November 20 2013 at 1:30pm |
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I once read that in the Chinese capital, the citizens stayed awake for a few days in shifts to make noise whenever the starlings went to land. This way, the shrieking disgusting disease ridden pests became so exhausted from flying, they actually died by their millions.
Hmmm... interesting technique. |
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LE Owner
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Posted: November 20 2013 at 5:01pm |
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I had almost thought you might have found some document stating the minimum acceptable dimensions for military spec ball cartridges, silly me.
Having no real information to support your simple statement that Headspace was of little or no importance to case life you just jammer on and attack the messenger instead of the message. That by itself is enough to prove that you are wrong and you know it. I've noticed a tendency for some to attempt to create their own myths by repetition. Some for instance will claim against all evidence that Cordite doesn't erode bores. Some will claim that bullet to bore fit has no effect on accuracy or that over sized bullets do not raise chamber pressure. About the most obtuse argument I've seen is the continued claims that the NRA UK withdrew their safety warnings on converted No.4 rifles due to some threat of legal action, which is ridiculous on the face of it. The warning is still in effect and No.4 rifles converted from .303 to .308 must be reproofed to be used in competition or limited to the lower pressure range .308 and 7.62 loadings. Then there's the claims that warnings on the unsuitability of the SMLE actions for high pressure cartridges originated with some shadowy and unidentified "American gunsmith". That actually originated from the manufacturers long before WW1. Theres always someone to quote some supposed blow up testing that for some reason left no actual records, and someone claiming that they heard of an SMLE chambered for the .300 short magnum cartridge, no information just unsupported claims. When I've posted documented evidence from the official records of debates in the house of commons the reactions are truly laughable. The crap from the cheap seats gets so deep sometimes hip boots seem in order. So why don't you find that document or just stop posting if you have nothing to contribute. I'll settle for good headspace and a tight chamber while you guys go hunting for rubber bands and tape to make up for lousy headspace and wallowed out chambers or use up the 50-60 year old milsurp while the primers are still likely to work half the time with hangfires you could measure with a grandfather clock. If I had no interest in rifles other than to hear them go bang I'd buy a cap buster.
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Shamu
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Posted: November 20 2013 at 8:43pm |
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"So why don't you find that document or just stop posting if you have nothing to contribute."
Not your place to make such a suggestion. play nice or............ |
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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hoadie
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Joined: March 16 2006 Location: Niagara/Canada Status: Offline Points: 9680 |
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Posted: November 20 2013 at 11:12pm |
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Oh my...TONY!!
 (Now your gonna get it!  Hoadie |
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Loose wimmen tightened here
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Shamu
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Posted: November 21 2013 at 12:32am |
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Hoadie. Why is TONY gonna get it?
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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hoadie
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Posted: November 21 2013 at 4:35am |
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TONY aint..its y'all arguing on the forum gonna feel the teeth of the Rottie! (Its OK Sham..methinks yer innocent & therefore will be spared.
 Hoadie |
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Loose wimmen tightened here
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Shamu
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Posted: November 21 2013 at 4:36am |
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Me? Innocent? wowsers well I never.
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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)
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A square 10
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Donating Member Joined: December 12 2006 Location: MN , USA Status: Offline Points: 16998 |
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Posted: November 21 2013 at 6:55am |
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"I once read that in the Chinese capital, the citizens stayed awake for a few days in shifts to make noise whenever the starlings went to land. This way, the shrieking disgusting disease ridden pests became so exhausted from flying, they actually died by their millions.
Hmmm... interesting technique." i like it - now to get the wife to stay up while i sleep to carry this off , i hate those blasted starlings , i wish the english imagrants had not brought them here - song birds - bah humbug ......oh and sparrows as well ,
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Tony
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Posted: November 21 2013 at 7:59am |
He'll be playing nice now!  |
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Rottie (PitBulls dad.)
“If electricity comes from electrons, does morality come from morons Born free taxed to death!!! |
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303Guy
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Posted: December 21 2013 at 6:07am |
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I've witnessed the effects of excess headspace but I mean very excess. Bolt setback is accelerated exponentially until peening of the lug recesses jambs the bolt. Rubber bands or O-rings is a stop gap measure for larger but still in spec headspace. But more than that it is a means of centering the case in a loose chamber on first firing. My first Lee Enfield had a pretty tight chamber but even so, I only got three firings on a case if I full length resized. A fourth firing would separate the case head. Once I figured out the problem, case life became infinite provided I remembered to anneal the necks and didn't loose them in the long grass.
So what I'm suggesting is that using some means of holding the case centred and hard against the bolt face is a case life and accuracy measure, not an excessive headspace 'repair' (but does overcome the excessive headspace problem but does not address the fact that the rifle may be worn). Anyway, for me brass life expectancy is infinite. I haven't had a case head separation in over forty years (not that I shoot every day). I also don't load to absolute max.
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303Guy
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As usual, the point is being missed.