My Savage barrels are either 26” heavy varmint or 22” light sporter.Small barrels heat up more than big barrels. I think that the amount of heat generated by firing a cartridge is the same for barrels of any diameter or weight and only varies slightly by length-most heat happens early. I think.Then the skinny 22” barrels have a higher temperature after N shots than the fat 26” barrels because heat quantity is constant.I and others shoot slowly = few shots per hour in order to keep the temperature down; because we think 1. that hot barrels erode-wear-burn more than cooler, and 2. that hot barrels make shot location change.
I/we have developed methods of cooling barrels including fans and water poured through the bore. None of these is perfect.
Is there a modification to or attachment for a rifle barrel that would reduce temperature?A copper cylinder threaded up to the barrel nut? A water jacket? A tube threaded at breech end and filled with ?lead/copper filings/aluminum?A
Hot barrels
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- Last Post 28 October 2014
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Joe; You could always build a water jacket around the barrel like a machine gun. Brodie
B.E.Brickey
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The easiest (and maybe the most efficient) would be an aluminum sleeve, finned. For calm conditions, vertical fins, like a Model 1927A1 Thompson sub-machinegun. For winding conditions, horizontal fins like a Lewis Aircraft machinegun. Ideal would be a tight fit over the entire length of the barrel and lots of thin fins at least 3X the diameter of the barrel. HTH, Ric
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Those of you who have read my other rantings about solving non-existent problems won't be surprised when I suggest that first we should try to find out if there is a problem.
I guess it is well established that when a machinegun barrel gets red hot it accelerates gas erosion. However, I assume that for the type of shooting with cast bullets that most of us do we are talking about a temperature rise of 100 ”€œ 150 F. or so. The temperature involved in eroding steel with hot gasses is in the thousands of degrees F. Whether the barrel starts at 70 or 200 degrees is a small difference compared to the high temperatures needed to do much erosion. Of course this is just theory so may contain bad assumptions and be wrong. But it at least thinking about it this way casts doubt that Joe's worry #1 is a problem. Worry #2 can definitely be a problem. We probably all have had a rifle that changed point of impact as it warmed up which might be because of barrel heating ”€œ or not. I assume the change, if any, is different for different barrels and probably depends on how well the barrel was stress relieved after the forging and machining on it was done. Do we have any data on this for modern free floated barrels? I know that hard core prairie dog shooters trade off rifles to control temperature. Do their bores wear out sooner if shot hot? Do they change rifles because of POI changes or because of experience with, or unfounded fear of, erosion? I don't think I ever noticed impact change during rapid fire strings shooting high power with the M-1 even with all that junk attached to the barrel but the old V ring was pretty big. John
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Greetings, A few comments and thoughts of a prairie dog shooter and from a family of prairie dog shooters. We would trade off rifles after a shot bag of cartridges to allow the barrel to cool off, and keep track of barrel heat while shooting. This allows for a 1964 Winchester Model 70 in .243 to still shoot center of prairie dog at 300 yards (last time I shot it on paper it kept 5 in less than an inch at 100 yards last spring). My father's 7mm Remington Mag still shot the same when he sold it after using it for a handful of thousand rounds. However, we had two friends that owned .264's. Art allowed for cooling as we did, and his Remington 700 BDL still shot very well when he passed on. Leroy, on the other hand, shot his rifle without care of cooling, and after the second trip his rifle would hold in a lunch plate at 100 yards, using the same loads as Art. So, IMHO, letting the barrel cool and keeping track of heat allowed the barrel to last. There may be other factors, but our experience was and is to allow the barrel to cool when shooting lots on a hot day. If anyone asks, I will shoot some groups and post them, but if I cannot get it done tomorrow it will be a couple months before I can get to the range again. TK
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tlkeiser: i believe you. I don't know about others who read this forum, but I am in complete agreement. I also think that Ric's suggestion of an Aluminum heat sink with thin fins would work. It would be a PITA to set up and maintain. Just think of those thin little fins all around the barrel ( fins like the ones on an air conditioner or car radiator). Building a case for it that would not let the barrel rest on anything --so they would not be bent thus destroying their heat transfer ability-- and still be easily portable would be interesting to say the least. Brodie
B.E.Brickey
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John,
An old ER Doc I worked with told me once; “If they think there is a problem, there is a problem.” But it may not be real, especially with lead bullets at less than one round per minute.
Ric
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Sometimes it is a good idea to get outside of your backyard and see what others are doing.I refer to FTR and target rifle shooters,shooting out to 1,000 yards,if the conditions are favourable,they belt them down and don't have any problems with inaccuracy.When I look at most of the cast bullet posts,the impression is that three shot groups are the norm,five shots are a big deal,ten is very rare and fifteen never happens.As I see it,most are to cautious ,what is the problem if a shot or two drifts out of the centre?Mike.
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I am with Ric and Brodie on how to solve this problem. No need to invent the wheel because it has already been figured out for machine guns. Well designed fins or a water jacket would work.
I think designing a slim water jacket would be fun for a prairie dog shooter who didn't want to take two or three rifles. Water absorbs way more heat than steel and it take an enormous amount per volume to boil and the boiling point of water would still be a pretty modest temp -- or the design could incorporate an easy way to replace the water and keep the barrel at a lower temperature.
The type of prairie dog shooter who needs more than one rifle to keep things cool shoots from one position. So -- better yet, a design incorporating water circulating to a gallon tank for a heat sink. The diameter of the water jacket could then be small and since there would be no reason to have a heavy barrel the barrel could be skinny. With a skinny barrel and a thin layer of water between the barrel and the jacket the outside diameter of the jacket might even be smaller than the usual varmint rifle. If the shooter thought he needed a rigid barrel for accuracy the jacket could be designed to support and stiffen the skinny barrel.
Although the project would be fun and make a great Fouling Shot article, the question is still -- is there a problem that needs a solution for cast bullet shooters and the type of shooting we actually do? So we probably should try to answer that first before we start reading up on water cooled machine guns.
John
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Stress in a barrel, usally from straightening, and bands and other stuff hanging on a barrel cause movement when hot. A good even thickness barrel that was stress relieved and free floating should not move much unless really overheated. If you really rip off the rounds your not into accurate shooting. Pick a cadence and allow some time between shots and strings. Taking two rifles to the range and alternating will help. Also less powder less heat. Frank C.
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with air-cooling the biggest problem is surface area exposed to the air. how about 10 feet of aluminum wool wrapped around the barrel ...
with liquid cooling, take advantage of liquid-to-vapor phase changing ... water takes 212 f., which is a very hot barrel ... so use alcohol which phase shifts much ( ? F. ) lower. if heating is only occasionally, how about a misting bottle of alcohol ..
i have always heard that during v. nam, the m60 crews drank a lot of beer ...
ken
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Those of you who have read my other rantings about solving non-existent problems won't be surprised when I suggest that first we should try to find out if there is a problem.
I guess it is well established that when a machinegun barrel gets red hot it accelerates gas erosion. However, I assume that for the type of shooting with cast bullets that most of us do we are talking about a temperature rise of 100 ”€œ 150 F. or so. The temperature involved in eroding steel with hot gasses is in the thousands of degrees F. Whether the barrel starts at 70 or 200 degrees is a small difference compared to the high temperatures needed to do much erosion. Of course this is just theory so may contain bad assumptions and be wrong. But it at least thinking about it this way casts doubt that Joe's worry #1 is a problem.
Worry #2 can definitely be a problem. We probably all have had a rifle that changed point of impact as it warmed up which might be because of barrel heating ”€œ or not. I assume the change, if any, is different for different barrels and probably depends on how well the barrel was stress relieved after the forging and machining on it was done.
Do we have any data on this for modern free floated barrels? I know that hard core prairie dog shooters trade off rifles to control temperature. Do their bores wear out sooner if shot hot? Do they change rifles because of POI changes or because of experience with, or unfounded fear of, erosion?
I don't think I ever noticed impact change during rapid fire strings shooting high power with the M-1 even with all that junk attached to the barrel but the old V ring was pretty big.
John
Heat isn't much of a problem with cast bullets, especially with big heavy barrels. I tend to shoot a fouler and 10 record shots in a 15 minute relay.22” skinny barrels with jacketed bullets heat up fast and hot. I'm shooting 5 in a 15 minute relay, with my timer going, and after 5 and 15 minutes the barrel is too hot to hold. I think I've seen shots going off somewhere in hot barrel jacketed, but I shoot so few I don't know for sure. I've got 25 loaded 243 and there's 2+ hours required to shoot them./The Savage small shank thread is, I think, 1.062” X 20. A BIG brass barrel nut with extensions? might do the trick.This, for me, is all about changing and testing Savage barrels.
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The pain threshold for skin is about 116 degrees F.
How hot is “hot", “real hot” and “really, really hot"?
After a 10-shot group with several sighters, I inserted a thermometer probe into the action of my rifle. After a minute or so, the reading was 116F. I monitored throughout the day, and it did not vary very much. The ambient temperature ranged from 70 to 80 degrees.
If you have ever shot out in the bright sunshine, with no cover, the sun will heat the barrel more than the powder charge.
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well said,Paul. sometimes comments are started to create controversy.
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If the aluminum suggested device is attached firmly enough to allow it to not fall off and to also actually suck some heat out, it will bend the barrel far more than the heated steel will do by itself. You have two materials with very dissimilar temp coefficients. The alum will expand rapidly. The steel not. Next thing you know your shots are drifting due to the heated aluminum. A motorcycle piston can swell .005 in a matter of seconds on a two stroke dirt bike with a modest temp change. I lost a nickel silicon sleeve to a forged piston with a bad jet setting once. Mic a 1/2 inch dowel of aluminum before and after heating to 200 deg. See what it does. Maybe 200 degrees is no problem but the charts show alum with double the growth of steel per thermal unit. If steel on my lathe expands .0015 under cutting temps, then that alum will give some wow factor around .003 or so.
It should be something that is loosely coupled with heat transfer grease such that the aluminum has some area to bend w/o moving steel.
Copper is more stable (well its awful close to the exp rate of steel, awful close!) and its one heck of a heat conductor.
I think the water jacket is the hot ticket. Made from steel. Barrel temp may never change But in reality, Im with John A, temps aren't high enough to justify any effort for cooling. Maybe if it were your varmint rifle in Montana on a great PD day. Then......... it would matter. or be helpful. But you will never pull the heat off the powder charge..... and thats whats hurting the bore. Sunburns only affect the skin, not your guts. Vice Versa.
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The pain threshold for skin is about 116 degrees F.
How hot is “hot", “real hot” and “really, really hot"?
After a 10-shot group with several sighters, I inserted a thermometer probe into the action of my rifle. After a minute or so, the reading was 116F. I monitored throughout the day, and it did not vary very much. The ambient temperature ranged from 70 to 80 degrees.
If you have ever shot out in the bright sunshine, with no cover, the sun will heat the barrel more than the powder charge.
Interesting. I'd not seen the threshold of pain for heat/skin quantified. It would be easy to affix a thermistor or thermocouple (or RTD) permanently in a rifle with a lead or connector to observe the influence of POI and chamber/barrel temperature.
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The principal reason I avoid 5744 in my '06 match loads is the heat it produces. 2400 is much cooler, dissipates quicker and best of all my 1917 Enfield loves it. Running a battery powered fan over the bore to blow away heat waves also helps.
Match Director
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Those of you who have read my other rantings about solving non-existent problems won't be surprised when I suggest that first we should try to find out if there is a problem.
I guess it is well established that when a machinegun barrel gets red hot it accelerates gas erosion. However, I assume that for the type of shooting with cast bullets that most of us do we are talking about a temperature rise of 100 ”€œ 150 F. or so. The temperature involved in eroding steel with hot gasses is in the thousands of degrees F. Whether the barrel starts at 70 or 200 degrees is a small difference compared to the high temperatures needed to do much erosion. Of course this is just theory so may contain bad assumptions and be wrong. But it at least thinking about it this way casts doubt that Joe's worry #1 is a problem.
Worry #2 can definitely be a problem. We probably all have had a rifle that changed point of impact as it warmed up which might be because of barrel heating ”€œ or not. I assume the change, if any, is different for different barrels and probably depends on how well the barrel was stress relieved after the forging and machining on it was done.
Do we have any data on this for modern free floated barrels? I know that hard core prairie dog shooters trade off rifles to control temperature. Do their bores wear out sooner if shot hot? Do they change rifles because of POI changes or because of experience with, or unfounded fear of, erosion?
I don't think I ever noticed impact change during rapid fire strings shooting high power with the M-1 even with all that junk attached to the barrel but the old V ring was pretty big.
John
10/1/14, 243 Win, Sierra 60 gr. #1500, WLR40/Varget, 5 to get on targetThen 5 + 5 in 15 minutes, FAST, HOT barrel, 1.75", 1.85"Next relay, 41 Varget5 + 5 in 15 minutes, FAST, HOT barrel, 1.7, 2.275"10 shots in 15 minutes is about as fast as I can shoot and hold well.I'll load the same loads and shoot slow next time.
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I don't know much about shooting jacketed bullets.While we were on the way to the range yesterday morning, Bob and I talked about copper fouling. I've been testing barrels with jacketed bullets, and noticed that there seemed to be little copper fouling and what there was was easy to get out. Years ago, copper fouling in a 222 Rem and 30-06 for example, took some time to get out.Bob, who shoots a lot of jacketed bullets, said that he found little copper fouling and it was easy to get out. The last time out with the 243 barrel I shot 25 shots slowly, and got ONE green patch out of the barrel, and could see no copper in the muzzle with a flashlight.Yesterday I shot 25 shots fast, same bullet, primers and powder. This morning I started cleaning about 3:15, Sweets 7.62, patch every 10 minutes or so, dry then Sweets, and I can still see copper in the barrel muzzle at 9:32. I don't know if shooting fast causes inaccuracy, but I do know that it caused barrel copper fouling.The barrel was clean at 10:30. I forgot what a pain cleaning copper was. Boy, do I have a lot of green patches!
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On a hot 90 degree day, shooting a BPCR 60 round match with a 74 Sharp (full 34” octagon) ... one could make a bacon-egg with cheese - toasted sandwich
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