How hot to shoot a barrel? How long to cool?

TargetNorth

TargetNorth

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Hi Everyone
I'm wondering about barrel heat and barrel wear. How hot do you guys shoot your barrels? How long do you let them cool off? My understanding is that if you shoot fast and shoot on a hot barrel, you will have an increased rate of throat erosion and will be buying a new barrel sooner.

My rule of thumb is I should be able to touch my barrel with bare hands comfortably. This generally works out to 10-15 shots of .243 in a factory pencil barrel, then walking to check targets, then shooting 3-6 or so and again checking targets. This is in 25C. I noticed that in -25 it cools a LOT faster.

My friends SL8 in .223 it seems can shoot at least double in the same amount of time.

Is there any simple formula or rule of thumb guide? What do you guys do?

Thanks,
Barry
 
For some competitions, the rules will dictate the rate of fire required. For just shooting by myself, I'll shoot 4-5 rounds through the heavy barrel 22-250, then let it cool. 1 round every 4-5 minutes with the 300WM with pencil barrel, and as much blasting as I feel with the CZ858.
 
Depends on many things. In F-Class, you shoot up to 10-20 rounds strings PLUS sighters. This is typically budgeted for 1 round per minute. This is too much for sporter weigth barrels and thus we tend to use very heavy barrels that act as a heat sink and resist heat warping.

We have an old codger that shoots a 6BR at our club and we bytch about the fact he is the world's slowest shooter. he also has a hummer 6BR with 5000 rounds (Twice the normal barrel life)

Shooting without over-heating pays huge dividends. Botom line is it depend on the cartridge, Even a well cared-for 6.5-284 is done at 1000-1400 rounds max. SOme are gone in as little as 700.
 
I've seen another shooter (and good friend of mine) get his match barrel so hot it sizzled the cleaner he was running through it for several minutes and the thing looks like a dogs breakfast with a borescope but shoots lazer beams.
 
Pretend it's your Unit and if you can't hang onto it for as long as you'd need take a leak in the can at a bar after a few, it's too warm.
P.S. No need to shake, just reload.
 
It makes intuitive sense that a barrel will cool faster in colder weather. I remember learning in second year thermochem that the rate of heat transfer is linearly proportional to the difference in temperatures. So compare an 80 Celsius barrel versus 25 Celsius ambient temp (55 degree difference) versus an 80 Celsius barrel versus -25 Celsius (105 degree difference, therefore twice as fast).

I'm shooting a .223 weather warrior with a pencil barrel, and it usually takes about 15 shots to get too hot to touch. Anticipating heat problems, I did some research and ended up buying a battery powered air mattress pump from canadian tire. It uses 4 D cells, but it's easy to substitute AA NiMH cells with D adapters. I use a piece of tygon tubing to hook it up to the end of my chamber (which never gets hot because brass carries away the heat), and it puts a nice flow of air through the barrel to cool it down faster. Granted, this isn't applicable for competition... but I'm still looking forward to trying out factory division F-class at some point in time.
 
Last year in summerland it was a really hot day, we were wrapping our barrels in towels and tshirts that we put into the cooler soaked in ice water.

Personally I follow the same principle that if it is too hot to hold on to for a bit I should give it a cool down break. That's usually when I switch find something else to do, switch to another gun or plink with the .22 for a bit
 
Ambient temperature has a big effect on barrel cooling as stated as does the cartridge. I have completed a ladder test involving 66 rounds of 338 LM over a short period of time through a Rock Creek 5R barrel. I have repeated this exercise on several occasions with the barrel reaching temperatures beyond where I can hold it with my hand.

The barrel has over 700 rounds through it. A careful inspection of the throat with a Hipp Endoscope shows the throat and rifling to be in very good condition.

Shooting 3,000 ft/s through a 6BR barrel has resulted in throat erosion over 1,500 rounds to the point where I can no longer load the cartridge long enough to maintain desired spacing. Part of the reason that I am moving to 6.5x47.
 
In a heavy match barrel in summer, shooting 17 rounds in ~30 minutes can result in the barrel being uncomfortably hot to the touch.

When I am testing ammo at the range, I'll put the rifle in a gun rack when I go to check and change targets, with the action open. The vertical hot barrel acts as a "chimney" and air flows through the bore as well as over the outside of the barrel, cooling it down quite a bit quicker than if I left it horizontal.
 
Mysticplayer answered my similar question about this a short time ago. He suggested running an experiment where you shoot until your groups start to open up. At that point you're too hot.
 
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