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Military developers have spent time measuring the amount of heat the fired cases remove from the chamber especially in machine guns. This is the issue that stopped further development of caseless ammunition. You could go to a Hi Power match and measure temperatures on brass from the gas guns compared to bolt guns, at least if you can still find folks shooting .308/7.62.  jim
LCDR Jim Dodd, USN (Ret.)
"If you're too busy to hunt, you're too busy."
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Campfire Kahuna
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Campfire Kahuna
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Jim,
Yeah, I came across that info about caseless ammo when doing some research.
Actually, what I will probably do is just go to the range with various rifles and do some timed shooting.
After thiking about this, I suspect one reason for the heat buildup is that the rear of the chamber of most semi-autos is more enclosed by the action than that of many other centerfires. This is obviously also the case with most pump guns.
A bolt gun, on the other hand, is much more open when the action is cycled, and even when shot quickly the next round isn't in the chamber as quickly, even when the rifle's being shot by somebody who can really work a bolt. I am pretty quick myself, and have been timed getting aimed shots off from a bolt a second apart, and would assume half that time involved getting the next round in the chamber. A half-second is a lot slower than 1/10th of a second, or however long it takes to a sem-auto takes to cycle.
One thing I have also noticed over the years is how quickly many single-shot rifles cool down compared to even bolt rifles. This is partly because I've done a lot of prairie dog shooting with various single-shots, including Ruger No. 1's, Brownings and various break-open rifles. When you open a No. 1 the rear of the chamber is MUCH more exposed to air circulation than even a bolt rifle's chamber.
One thing I am a pretty fan of is empirical evidence, and from shooting I KNOW that the cases come out of semi-autos hotter than they do from other actions, at least after the first shot. Now I intend to find out why, or at least make the attempt.
One thing I forgot to note in any earlier post that is one of the reasons my gunsmith friend thinks the chambers of aemi-autos pit in humid climates is that the boys don't oil the chambers, as they do in bolt rifles, even if inadvertently, due to the chamber being harder to get at. A chamber that gets hot and is never oiled ain't a good thing in West Virginia!
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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Campfire Ranger
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Campfire Ranger
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I think the reason brass is so hot coming out of a semiauto is because it doesn't have much time to transfer any of the heat into the steel of the chamber.
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Campfire Kahuna
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Campfire Kahuna
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That just might be part of the reason. Thanks for the idea!
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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At an Army range, the guy next to me fired his M-14 and the ejected case hit me in the face and caught under my helmet strap. I finally clawed it out and it left a nice (temporary) mark. Hurt like hell. Just wasn't my day.
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Campfire Kahuna
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Campfire Kahuna
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Somebody on our range once had a hot semi-auto case go down his short collar. He did quite a dance!
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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Campfire Outfitter
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Campfire Outfitter
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Somebody on our range once had a hot semi-auto case go down his short collar. He did quite a dance! I was shooting my AR15 (in sitting position) to the left of a guy who had trouble keeping his pants up. Part way through a course of fire I sent a hot case right down the crack. Lesson learned, and laughs enjoyed!
Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery.
--Winston Churchill
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Campfire Ranger
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Campfire Ranger
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Back in 1979 in Boot Camp, all us southpaws had burn blisters and scabs on our faces, often the same shape as a sideways 5.56mm casing.
The M16A1 didn't have the brass deflector. The brass comes out hot enough to give a second degree burn.
On the rifle range, sometimes a casing from the shooter on your left would fly out and land on the back of your neck (prone). That'll test your concentration....grin
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Campfire Tracker
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John, You need not "investigate" anything. I guess I just cannot understand that you cannot understand that the quicker a case is ejected from a rifle the hotter it will be.
There are no "theories" only facts as Physics and heat transfer are ruled by the laws of thermodynamics.
If you could cycle any action as fast as a semi-auto, the case would be just as hot, the barrel the same temp and heat transfer to the next round identical.
Insofar as "dry chambers", well they should be dry as should any rifle chamber. If the people who owned the rifles cleaned the chambers, they would have no problems. Every M-1 issued came with a tool that had as one of its functions,cleaning the chamber. I guess the military figured it out but the folks with the rusty chambers visiting your gunsmith have not. Perhaps semi-autos need a "clean chamber" warning lights to remind folks the way a "service engine soon" light does on their cars.
I assume nothing about others knowledge unless I know them (unlike you) but suggesting that a 200 gr bullet in a 300 Savage to be shot at ranges out to 250 or so is superior to a 150 TSX is just flat wrong AS MANY OF THE INFORMED WRITERS FOR WOLFE PUBLICATIONS HAVE PROVEN.(You might want to look at Roberta Scovill's Elk in the new issue of Rifle and see what she killed it with and how far away it was. HINT Barnes TSX 150 gr)
I'm trying to walk away but you just won't stop insulting me and questioning my grasp of Physics 101. There just is no mystery to this mystery. Semi-autos eject hotter cases, dry chambers in humid climates can rust, regardless of the action type, people who properly maintain their rifles don't have rusty bores or chambers. My three Ars, M-1, M-4 & M-8 (Remingtons), Merkel SR-1 and Benelli R1 as well as a pile of 1911s all are shot a lot and NONE have ever had a rusty chamber.
A simple pull through with a Hoppes bore snake with a bit of Kroil on a patch in the loop, after the hunt, will take care of the "dry chamber".
Another pull thru with a dry patch in the loop before the next hunt will restore the chamber to being properly dry.
Perhaps a chat with Mike Venturino who owns and shoots a slew of semi and full auto weapons would avoid testing any theories.
Regardless of further not to subtle "expert vs idiot" treatment, I am moving on.
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Campfire Kahuna
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Campfire Kahuna
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oldsman1942,
Prior to this, the closest you came on this thread to even admitting that a case comes out out a semi-auto hotter than from any other action involved shooting one 5 times quickly. Other than that you claimed they wouldn't be hotter than cases fired in any other rifle. Now, suddenly, you say OF COURSE they come out hotter--and for reasons that were discussed by other people than you (including me) after your last post.
As for dry chambers, the gunsmith who told me about the pitted chamber problem was Melvin Forbes, the founder/owner of New Ultra Light Arms, who was a general gunsmith for many years before starting NULA. He knows quite a bit about rifles and how they work--and how they don't work. He was just stating the facts as he knew them. Apparently those facts offend you.
As for the 200-grain Speer thread, I just grew weary of you belittling anybody who wanted to shoot 200 Speers from his .300--or indeed any other bullet than a 150 TSX. The 200 Speer wouldn't be my first choice in the .300 Savage, but why not? It's a free country--unless, apparently, somebody doesn't believe in exactly the same bullet you do.
The reason Roberta Scovill used a Barnes TSX is because she is married to Dave and he loads all her ammo. Unless Dave is forced to (say, by a hunting invitation by some other bullet manufacturer) all he loads are Barnes X's.
Many years ago Dave told me the reason he only used X's was that none of the other staff writers used them. This wasn't exactly correct (I started using Barnes X's around 1990, for one) but one reason I believe he uses so many TSX's is that he has been a close friend of Randy Brooks for many years.
I have seen about 150 TSX's shot into animals (a good portion of which I shot myself) and they are good bullets but they are not the only bullet in the universe, despite your opinion or anyody else's. In fact they even have disadvantages, though apparently you aren't aware of those, another little detail that makes me doubt your massive knowledge.
I don't think you are an idiot, because obviously you can type reasonable English. I do think you are arrogant, and believe there is one answer to everything: yours. That opinion is based not on a wild guess but many of the posts you have made on the Campfire.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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Before you say what I said, I suggest you read my first post "Heat generated by gas guns? These are not ARs, there is no gas in the chamber except the slight residual amount long after the bullet has left. An autoloader clears the case (and the heat) much faster than any other action. Rough maybe, pitted well that's lousy maintenance." What part of the case and the heat was unclear? Insofar as TSX "disadvantages" they are accurate, poke two holes in game, break bones and don't come apart. This Mulie was taken on the 9th at 80 yards, offhand, from a 99R with 130 TTSX starting out at 2800. Two holes, , two broken ribs, wrecked the lungs, left a 2" exit hole, she went 20 yards spraying blood like a power washer. ![[Linked Image]](http://i191.photobucket.com/albums/z231/leadloader/DSCN2945.jpg) I hardly believe there is only one answer, but there are some that are some better than others. I still am at a loss as to why you have to "shoot the messenger" rather than being able to list any facts to support your position that autoloaders are at some disadvantage due to the fact that they are autoloaders. I really don't care about your gunsmith's resume', what I care about is answering why an autoloader MIGHT have a slightly higher chance to have rust in the chamber than a bolt gun. The answer was and is simple: people are not cleaning the chambers. If you can refute that with factual data, I'll listen eagerly. Finally, in polite conversation, it is not necessary to preface every opinion or fact cited with: "Well, I could be wrong, I have been wrong in the past, you may not agree with me and you might be right, BUT this is what I believe." I haven't noticed it in your opinions and feel no need to add it to mine. On some other websites, gunwriters are constantly ridicules as paid off pawns of sporting goods companies, outfitters etc.. I don't share that opinion as most of the stuff I read is reasonable and usually well supported. I await the detailed article in Rifle, supporting the thesis that autoloaders are inherently prone to chamber corrosion and that a hot case on the ground is worse than a hot one in the chamber. As this thread is fast becoming a "mine is bigger than yours" contest and thread is prefaced with your name, I think it's time for me to get back to the threads where things are more relaxed. Good shooting!
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Campfire Regular
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Campfire Regular
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A couple of thoughts: Perhaps because extraction on a semi-auto action starts almost instantly after firing, the case may not be done contracting enough to avoid some friction that a manual action may not experience. Also, the case is snatched out of the chamber while that area is still full of 500+(?)degree gas causing a blast of super-hot gas to pass along the chamber walls which would tend to cook away any residual lubricant/corrosion protection. Since the temperature in the throat goes from sky-high all the way back down to ambient in just a few minutes, the temperature-drop curve during the first few tenth's of a second must be pretty dramatic.
I agree with Mule Deer's statements and my limited observations agree with his. Thank you, everybody, for your thoughtful inputs, especially JB.
Nifty-250
"If you don't know where you're going, you may wind up somewhere else".
Yogi Berra
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Campfire Kahuna
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Campfire Kahuna
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Oldman1942,
I thought you were out of this?
Do you know of any .30-06 aemi-autos that are NOT gas operated?
Here is an example of your "unbiased" opinion about bullets:
"Well you are free to believe whatever you want about Barnes. The guys I know have killed 100s of head of Deer, Elk, Antelope, Moose, Goats, Sheep and Bear with Xs, TSXs, TTSXs & MRXs. We have tried every hunting bullet under the sun (some of them are even older than me) and there is nothing better.
No animal has EVER been lost and almost all were one shot kills."
This is from a recent thread on the Campfire.
So you shot a muley doe with a TSX and it died. Whoopee. I have shot something around 100 animals with super-pentrating hollow-points, including the Barnes X (from the original to the "blue meanie" to the TSX and the Fail Safe). Every darn time the bullet went into the right place it killed the animal, almost always with one shot. Amazing! The only problem was, sometimes they went a long ways before keeling over, especially deer-sized animals.
I have also done the same thing with a whole list of other bullets. When did super-penetration become The Anwser, especially on snimals the size of muley does? If that were the case, we'd be shooting solids.
Over the past decade I have paced off the distance to where every well-shot (center of heart-lung area) animal eventually fell over. The animals shot with super-pentrators went over 50 yards, on average. Those shot with bullets that expanded wider (and even lost some weight!) fell quicker, because the hole inside them was bigger.
You are fond of throwing around words like "physics" and "thermodynamics" as if we common people won't understand them. Well, one basic fact of physics is that penetration of a big game bullet is mostly due to a smaller frontal area, NOT retained weight. A smaller frontal area makes a smaller hole, which means that average animals don't die as quickly. A deep-penetrating bullet is most useful on really big animals.
Which is exactly why, after 15+ years of using bullets like the Fail Safe, Barnes X, etc., I have gone back to using bullets like the common lead-core bullets (that cost half as much) for shooting deer. They kill quicker, on average. In fact, the quickest-killing bullets I have used on deer-sized game has been Berger VLD's, which open up violently.
Also, hollow-point "super penetrators" don't open up on occasion. I have seen this a number of times not just with X's but Fail Safes (and a lot of HP varmint bullets). Out of 150 TSX's I have seen used big game, 6 did not open.
Even though they didn't open, they still killed the animal, as of course they have to, but not nearly as quickly as an "inferior" lead-cored bullet would have.
I do not write for RIFLE anymore, after writing for the magazine for over 15 years, due to a disagreement with the new owner (who bought it a couple of years ago) about such basic things as pay. But I have written about this very subject, with lots of back-up info, for RIFLE and several other magazines.
Last edited by Mule Deer; 10/12/09.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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Campfire Tracker
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Johnson M1941 is a short recoil operated, semiautomatic rifle. you want more? I don't worry about what bullets cost, I worry about how they perform. I've been at it 52 years on my own dime so endorsing a product for a free trip is not on my list. New issue of Rifle is excellent, especially that Elk killed with the puny 7X57 and a 150 TSX. BTW, I chroned 10 7x57s loaded with W 760, CCI 250s and 120 TSXs. 5 had been kept nice and warm in the 68 degree house, 5 in the 15 degree barn. Average velocity variation was 3 fps. Don't think that is statistically significant. (another "fancy term" you can look up at: http://en.wikipedia.org/wiki/Statistical_significance) Adios
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Campfire Ranger
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Campfire Ranger
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What is the "statistical" probability of you wearing out your welcome here as you have with every other forum. I'm betting high.
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Campfire 'Bwana
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Campfire 'Bwana
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BTW, I chroned 10 7x57s loaded with W 760, CCI 250s and 120 TSXs.
5 had been kept nice and warm in the 68 degree house, 5 in the 15 degree barn. What was the temperature of the rifle in each case?
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Campfire Ranger
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Campfire Ranger
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I don't have a dog in this fight, and I don't want to have a dog in this fight. However,
I've been in the military for 33 years on and off, and would bet the reason the chambers of the semi autos are more pitted is because, until the recent advent of the bore snake and similar, it was too much of a pain in the butt to run a patch through from the chamber side of a rifle, and every gun rag written speaks of cleaning from the muzzle end as if it were the work of Satan.
Bolt actions: remove bolt, swab, repeat as necessary, replace bolt. Easy as pie.
Why then, you ask, don't the chambers in M-16s and M-4's rust and pit? Two reasons. One, that rifle is easy to take apart and clean from the chamber end of the barrel, and two, we're driven to clean our weapons if not daily, at least often.
And, hot gasses blown back in the chamber for semi-autos would dry out the chamber faster, requiring cleaning more often, which, as mentioned is a pain in the butt without a bore snake. Dry chamber left from year to year = pitted chamber.
Last edited by David_Walter; 10/12/09.
“Live free or die. Death is not the worst of evils.” - General John Stark.
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Campfire Ranger
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Campfire Ranger
Joined: Jan 2006
Posts: 21,810 |
Oldman1942,
I thought you were out of this?
Do you know of any .30-06 aemi-autos that are NOT gas operated?
Here is an example of your "unbiased" opinion about bullets:
"Well you are free to believe whatever you want about Barnes. The guys I know have killed 100s of head of Deer, Elk, Antelope, Moose, Goats, Sheep and Bear with Xs, TSXs, TTSXs & MRXs. We have tried every hunting bullet under the sun (some of them are even older than me) and there is nothing better.
No animal has EVER been lost and almost all were one shot kills."
This is from a recent thread on the Campfire.
So you shot a muley doe with a TSX and it died. Whoopee. I have shot something around 100 animals with super-pentrating hollow-points, including the Barnes X (from the original to the "blue meanie" to the TSX and the Fail Safe). Every darn time the bullet went into the right place it killed the animal, almost always with one shot. Amazing! The only problem was, sometimes they went a long ways before keeling over, especially deer-sized animals.
I have also done the same thing with a whole list of other bullets. When did super-penetration become The Anwser, especially on snimals the size of muley does? If that were the case, we'd be shooting solids.
Over the past decade I have paced off the distance to where every well-shot (center of heart-lung area) animal eventually fell over. The animals shot with super-pentrators went over 50 yards, on average. Those shot with bullets that expanded wider (and even lost some weight!) fell quicker, because the hole inside them was bigger.
You are fond of throwing around words like "physics" and "thermodynamics" as if we common people won't understand them. Well, one basic fact of physics is that penetration of a big game bullet is mostly due to a smaller frontal area, NOT retained weight. A smaller frontal area makes a smaller hole, which means that average animals don't die as quickly. A deep-penetrating bullet is most useful on really big animals.
Which is exactly why, after 15+ years of using bullets like the Fail Safe, Barnes X, etc., I have gone back to using bullets like the common lead-core bullets (that cost half as much) for shooting deer. They kill quicker, on average. In fact, the quickest-killing bullets I have used on deer-sized game has been Berger VLD's, which open up violently.
Also, hollow-point "super penetrators" don't open up on occasion. I have seen this a number of times not just with X's but Fail Safes (and a lot of HP varmint bullets). Out of 150 TSX's I have seen used big game, 6 did not open.
Even though they didn't open, they still killed the animal, as of course they have to, but not nearly as quickly as an "inferior" lead-cored bullet would have.
I do not write for RIFLE anymore, after writing for the magazine for over 15 years, due to a disagreement with the new owner (who bought it a couple of years ago) about such basic things as pay. But I have written about this very subject, with lots of back-up info, for RIFLE and several other magazines.
Excellent reply JB, but do keep your cool. Oldman1942 is a younger man(?) than me and I'd love to shave a couple of years off the calendar, but I do manage to do my yearly trailcrew work in National Forests with the National Smokejumper Association.
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Campfire Ranger
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Campfire Ranger
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Posts: 21,810 |
What is the "statistical" probability of you wearing out your welcome here as you have with every other forum. I'm betting high. +1 on this one!
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Joined: Jan 2006
Posts: 21,810
Campfire Ranger
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Campfire Ranger
Joined: Jan 2006
Posts: 21,810 |
Johnson M1941 is a short recoil operated, semiautomatic rifle. you want more? I don't worry about what bullets cost, I worry about how they perform. I've been at it 52 years on my own dime so endorsing a product for a free trip is not on my list. New issue of Rifle is excellent, especially that Elk killed with the puny 7X57 and a 150 TSX. BTW, I chroned 10 7x57s loaded with W 760, CCI 250s and 120 TSXs. 5 had been kept nice and warm in the 68 degree house, 5 in the 15 degree barn. Average velocity variation was 3 fps. Don't think that is statistically significant. (another "fancy term" you can look up at: http://en.wikipedia.org/wiki/Statistical_significance) Adios Ah, excuse me Oldman1942, but are you a currently certified jackass or just working toward this level?
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