Barrel Cooling

[trader388]

I've been reading on these boards that to pro long the life of your barrel you should let it cool between shots.

What is cool? How long does it take? How many shots can I take before it needs to cool. I realize that all this depends on many factors...but I would appreicate some general ideas or rules.

 

[Guest]

I consider my barrels to be "cool" when I can rest the bottom of my wrist on it for extended periods with out any disscomfort.

I consider my barrels to be hot if I can't keep my palm on the barrel (about 6" in front
of the chamber) without disscomfort.

This is a very crude way to measure but it seems to work , most of my heavy barreled magnum guns get hot in about 5-7 shots , a 308 maybe 10 shots.
I have two 308 that have the same size barrel but one is fluted , shooting the same loads out of each one I haven't been able to see that the fluted barrel cooles any faster.I personaly like to have ALOT of space around my barrels to let them breath most of my guns have about 1/4" free float to let more air around the barrel

 

[4ked Horn]

JD I have often wondered why so many shooters go for the "I can slip a business card between my barrel and stock" distance for free floating? I think at least 1/16" is more functional especially if you tighten your field rest with a sling and I must say that when I finally build my current dream rifle it will have at least 1/8" clearance from the end of the chamber out to the tip.

 

[baldeagle713]

[ 03-13-2004: Message edited by: baldeagle713 ]

 

[Darryl Cassel]

In 1000 yhard competitions where 10 shots are fired for record and 5 to 10 sighter shots were fired first, the barrels do get extremely hot. This is especially true in the 90 degree heat and dosen't matter if the shots are fired fast or slow. The barrel still heats up till it will burn the hand if you hold the barrel for any length of time.

Just to give you an idea of how long a good barrel will last even when it is heated to extreme, the Hooovers, who are great shooters, shoot their barrels until they have 2000 rounds on them and then they rebarrel at that point. They have found that, at that point, it is usually at the end of "two seasons" or years of competitions for each rifle. John has stated they (the barrels) are still shooting fine even at that point. They just don't want a berrel to go south in the middle of a season.

If you shoot more at one setting and in the time frame of 10 minutes then the above mentioned amount of shoots, the over heat will no doubt effect accuracy but, 15 to 20 shots does not seem to do this, at least not from what I have seen.

If you have a pencil thin barrel the info above does "not" apply.

Later
DC

[ 03-13-2004: Message edited by: Darryl Cassel ]

 

[dbhostler]

A few years ago there was a company by the name of Norlin Enterprises in Sioux Falls, SD that sold a barrel cooling system by the name of "Winter Breeze Barrel Cooling System". The idea was to blow CO2 down the bore with a special adaptor that fit the chamber. The tanks that were used were common soda pressure "barrels" that could be recharged at your local vendor or gas supply. He also included in your order small stick-on LCD thermometers that eliminated the guess work on how hot your bbl was and when to stop shooting. Don't know if this system is still available on not, but it sounded like a better idea than dunking the rifle in a barrel of water.
db

 

[rlipson]

I remember reading a fairly compelling article (can't remember the source, duh!) that laughed at the idea that external barrel temp. meant anything. The author discussed the temps. achieved in a chamber at the time of firing and said the temp. between shots was so much lower that it was insignificant as far as "frying" a barrel short of firing full auto. I've always followed conventional wisdom (if the barrel's too hot to touch/hold, let it cool!). But I've always wondered whether it was "common sense" folk wisdom that could be backed up metallurgically.

I'd be interested in some sicence on this as opposed to what we "think" is important.

Let's face it, lot's of machinery runs at temperatures too hot to touch.....with that said, I'm sure as heck no metallurgist, engineer, physicist or even much of a mechanic..so what do I know! But I'd like to learn.....

[ 03-14-2004: Message edited by: rogerinneb ]

 

[Guest]

I made up a rig that I would place into the chamber and run cool watre down the barrel to cool it , it works reay well and I still use it every once and a while if I only have one gun to work with.

I have a couple around someplace that you guys are free to try if you wanted.

 

[jb1000br]

JD--I made one too--a little plastic funnel and a piece of hose that canjam into the shoulder area in the chamber--instant cool with less than a quart of water.

JB

 

[dwm]

I found some adhesive plastic temperature strips which change color as the temperature rises. They read out in degees.

They don't cost much.

Let me know if you are interested.

 

[Mysticplayer]

Here are my stock shapes that help with cooling and REALLY free float the barrel.




The main reason is that the space allows me to wrap the barrels with wet cloths. In the summer, our temps get up there and if I let it air cool, it would take about an hour. By wrapping with cold wet cloths, it only takes a few minutes even with these heavy barrels. The cooling is also even around the barrel.

Even if there is a "big" space, the stock is still an excellent insulator. I didn't like the idea of one half of the barrel "insulated". Maybe cause uneven barrel heating and more walking during the next string.

I put ice and water in a cooler and throw the clothes in that. Keeps the drinks cold too.

As to the guy thinking that the chamber is much cooler then the surface, I don't buy it. Yes, there will be a temp gradient across the steel but the difference when the outside gets hot, is minimal. The big differences would only occur if a coolant was running down the bore.

Remember the hot poker in the fire. The end you hold gets pretty hot. Steel transfers heat along its surface very evenly. Wood doesn't, but we don't use wood barrels.

Jerry

 

[coyote_runner]

I don't shoot very big calibers but i do know is that i would let it cool down after shooting a clip. that is what i found that works best. if you start to shoot 2 or 3 clips you might burn your barrel out.

 

[dwm]

Temperature strips sold by Omega - $12 for 10 of them, part number: RLC-50-30/60-10 go from 30 to 60 degrees C or from 86 to 140 degrees F.

Omega URL:

Omega Temperature Strips

Pictures of the strips:

Here is a picture of my 7MM RUM with the temperature strip stuck to the barrel right in front of the receiver:

Works great in the summer when it is hot and the barrel takes a while to cool.

This way you can tell for sure if the barrel is the same temperature for each shot.

[ 03-16-2004: Message edited by: dwm ]

 

[jb1000br]

dwm--im interested in the temp strips--email me please.

JB