how hot is hot?

[oakflat]

O.K. I keep hearing not to get your barrel too hot! Well how hot is too hot, I have yet to find any info in any location as to this question. What I would like to hear is a temperature that is getting into the range that can actually cause damage. Say something that could be measured with an oven thermometer in the end of the barrel. Over many years of flying, cylinder temps were a BIG deal and for the best engine and operator life we tried to stay under about 375-400 degrees, this with aluminum heads and steel cylinders. I would like to hear both facts and opinion.

Thanks
Oak Flat

 

[Stevewix]

O.K. I keep hearing not to get your barrel too hot! Well how hot is too hot, I have yet to find any info in any location as to this question. What I would like to hear is a temperature that is getting into the range that can actually cause damage. Say something that could be measured with an oven thermometer in the end of the barrel. Over many years of flying, cylinder temps were a BIG deal and for the best engine and operator life we tried to stay under about 375-400 degrees, this with aluminum heads and steel cylinders. I would like to hear both facts and opinion.

Thanks
Oak Flat

Oak Flat, I'll share my experience. It may or may not be factual, but it's what I've observed.

Barrel temp matters most when considering ammunition. Specifically, temperature sensitivity of the powder and primer combined with how long the round 'cooks' in the chamber.

There are smaller variables that will likely come down to matter of opinion. If the bedding job isn't 'stress free', there will likely be a POI shift. In addition to this, pressure pointed barrels that are accurate on a cold bore will likely suffer a POI shift.

This said, if the barrel is floated and the bedding job is stress-free, the only change from a 'warm' barrel, I.e. 2 to 5 shots should come from additional velocity from heating of the powder inside the ammunition.

 

[Varmint Hunter]

Opinion:

If you can't comfortably hold your closed hand around the barrel then it's "too hot". How's that for scientific? Used by more shooters than any other method!

 

[lamiglas]

+1 -thats the method that me and the guys I shoot with use. I try not to let it ever get to that point, but while we are shooting, after each shot we will grab hold of barrel and close our hand. when it gets to the point that we have to let go, we stop and let it cool. again, we usually will stop before that and space out our shots but that isnt always how it goes.

 

[oakflat]

Yeah, the old "hold and wince" method has worked for years, I just thought I would try for something a little more technical/accurate. It seems that hot to the touch is in the neighborhood of about 180 degrees which is not hot for good steel but may start to cause copper to smear under pressure and the heat of firing. Any other thoughts out there??



Oak Flat

 

[silvertip44]

Looks like the old hand job is about the easiest and probably the best way to make that determination. Otherwise, just time your shots.

 

[cowboy]

The old hand method has been around since the buffalo hunters used their canteens to pour water over the barrel to cool them.

If you have trouble with using your hands - I say use your cheek and that will tell you when you're getting too hot.

Hot here in Montana may be 3 quick rounds on a prairie dog farm with a high velocity wixbang or it may be many more rounds than that today where it's 40 degrees and a slight breeze.

 

[Vermonter]

Only place i heard about the temp of the barrel being a problem is machine guns. But a long range rifle, never heard anything about it. I heard a lot about cars and when drag racing they like to run hot or colder. My gun loves it hot, she likes to shoot hot and when hot smaller than 1" groups at 100 yards. And the gun is a '39 Mosin Nagant 91/30.

 

[oakflat]

O.K., today I found a reference to "how hot is too hot" on a Darrell Holand shooting video. He states that you should operate your barrel between 80 and 150 degrees. He also states that much above that can shorten barrel life. That was the original question I was trying to get which is great! Now to take a thermometer out and check to see what that feels like on the old hand.

Oak Flat