I bought one of those little temp gages that you hold an inch away from an object, so I am wondering if any of you know at which degrees one should stop shooting and let the barrel cool. I wonder at which temp groups will begin to open up.

Should be interesting...

Don't know the temp. But, if I can't hold the barrel with my bare hand it is time to let it cool.

A group may or may not open with heat. But heat will for sure shorten your barrel life.

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Originally posted by ramrod340:
Don't know the temp. But, if I can't hold the barrel with my bare hand it is time to let it cool.

A group may or may not open with heat. But heat will for sure shorten your barrel life.

That's a good common sense reply. But there are and were times I shot a barrel a lot hotter then that.

quote:

That's a good common sense reply. But there are and were times I shot a barrel a lot hotter then that

I can't say I've always followed my own rule of thumb.

But get it HOT too often and you will cut the barrel life (I have a couple tent stakes to remind me).

I don't want to kill my $1,000 barrel job!

Depends on the application; for ARs; shoot until you run out of ammo. For bench rest guns; you won't shoot fast enough or long enough to hurt the barrel. For varmint barrels; shoot until you run out of targets. Basically, as you can see, I don't worry about it. For expensive barrel jobs, cooler is better. So let it rest a few minutes between groups.

The fact is that rifle barrels are consumables like brass, primers powder and bullets.

If you do the math, a barrel is only good for about 10 seconds of actual bore time. Do the math.

A good barrel in a sporting rifle should last a lifetime, a great barrel on a target rifle will last a season, maybe two.

Cut rifled barrels are stated to wear better (slower) than button rifled ones. My experience as a High power service rifle shooter bear this out. A Krieger cut rifled CM barrel on a NM M1 is doing fine after 4500, as was a Badger cut rifled on a NM AR (3920 before I could not reach the lands with 80s), but a button rifled version lasted less than 2500 before it lost both throat and accuracy at any range.

It is good advice to shoot slowly and allow cooling, but it probably does not really make that much difference in the total round count.

regard

The old rule of thumb is if you can't hold the rifle up by the barrel with your bare hand, it's too hot. Also, a wait of 1 minute should be made between shots. When you're shooting Pdogs and they're thick, a minute is a looong time. When I was shooting pdogs, I'd wait 1 minute between shots and after 5 shots, I'd switch rifles or give the one a 5 minute cool down.
If you're shooting from a bench or practicing, there's no reason to overheat a barrel. Even one of the platforms.

Shooting my 9.3 double rifle makes the thin barrels way too hot to touch after ONE shot and firing the second barrel makes it worse. Has a splinter forearm. You can feel the bullet go through it. There is no way I wait one minute between shots on any rifle. That is overkill; I have never heard of that rule; A barrel that is heated to only 150 would feel hot but not be even in the water boiling stage. Anyway, yes, cooler is better but there are limits to my patience and one minute is over that. I would give up way too many prairie dogs to do that.

160F is hot enough to blister your hand. 140 is normally too hot to hang onto and 120F is hot. A barrel can withstand temperatures in the 3-400F without affecting the metallurgy but depending on the metal it will wear faster as the temperature rises. It is a good rule of thumb to keep the barrel below 140 degreesF. You can shoot a stainless barrel to a slightly higher temp because the stainless is more wear resistant.

With an average of 2800 fps a gun will shoot 1680000 feet (through the barrel) in ten minutes. If we divide that by a two foot barrel we get 840000 shots. Even if we say the the acceleration down the barrel is linear and divide that number by two you still get 420000 rounds out of a single barrel.

Is there maybe something wrong with my math?

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Originally posted by Leopardtrack:
I don't want to kill my $1,000 barrel job!

I agree with Ramrod. But I would ask the smith that did the barrel job. If he is getting $1,000 to rebarrel a rifle he sure knows more than me....

Paul, I agree with most of what you've said but getting almost half a million shots out of a barrel seems kinda much. Even with my methodical pace, I don't think I've gotten that kind of mileage out of a barrel. I can't be sure however as I'm not a "counter" of things.

quote:

Originally posted by PaulS:

With an average of 2800 fps a gun will shoot 1680000 feet (through the barrel) in ten minutes. If we divide that by a two foot barrel we get 840000 shots. Even if we say the the acceleration down the barrel is linear and divide that number by two you still get 420000 rounds out of a single barrel.

Is there maybe something wrong with my math?

You changed 10 seconds into 10 minutes.....

quote:

Originally posted by HPMaster:
If you do the math, a barrel is only good for about 10 seconds of actual bore time. Do the math.

My experience has been as follows.If you want really tight groups-less than an inch at 200yds you should not get the barrel hot at all.If you do get the barrel hot it will kill that type of accuracy instantly.When I shoot in the winter months and my barrel almost never gets hot it is amazing how long it will take for the rifling to go compared to shooting in the summer months.
A barrel that only fires two or three sets of five shot groups on a cool day will stay super accurate week after week and last a very long time.If you take a new barrel out and shoot 50-100rds in only a few minutes on any day accuracy will be effected so much that if it shot within an inch at two hundred it will now shoot within 6 inches or worse(not sure if this is because of the bore dialating or eroding).
Keeping a barrel cool and selecting a heavy barrel is the key to accuracy.It is not as easy as that however since you will want to shoot it as often as possible-especially for target practice.If you want to win a match or get the tightest group possible dont use a barrel that you have been putting rds through.

I've always followed the "If you can't hold your hand on it, let it cool" rule. But slightly off topic, What about full auto? Do M16's wear out barrels every day? I know some of the larger full autos are water cooled but what about smaller machine guns?

I thought of experimenting with putting ice packs on the barrel to cool it quicker between groups....have any of you ever done this?

quote:

so I am wondering if any of you know at which degrees one should stop shooting and let the barrel cool. I wonder at which temp groups will begin to open up.

"...which temp groups will begin to open up." - 127F

" ... which degrees one should stop shooting and let the barrel cool." -- 346F

??????

quote:

Originally posted by Leopardtrack:
I thought of experimenting with putting ice packs on the barrel to cool it quicker between groups....have any of you ever done this?

I have heard of that but I would think that would be a great way to distort a barrel.

Every so often some writer runs an article about some gizzie that cools the barrel with cool air or cold water. I've never seen one of these devices at an actual match. So, imo, if they were effective, I'm sure every competitor would have one. My thinking is if you don't let the barrel get too hot, then you don't have to worry about it.

quote:

Originally posted by JBrown:

quote:

Originally posted by PaulS:

With an average of 2800 fps a gun will shoot 1680000 feet (through the barrel) in ten minutes. If we divide that by a two foot barrel we get 840000 shots. Even if we say the the acceleration down the barrel is linear and divide that number by two you still get 420000 rounds out of a single barrel.

Is there maybe something wrong with my math?

You changed 10 seconds into 10 minutes.....

quote:

Originally posted by HPMaster:
If you do the math, a barrel is only good for about 10 seconds of actual bore time. Do the math.

You are absolutely right! My mistake.
So, 420000 / 60 = 7000 rounds

That sounds a bit low to me but a lot closer than with my mistake.

quote:

Originally posted by wasbeeman:
Every so often some writer runs an article about some gizzie that cools the barrel with cool air or cold water. I've never seen one of these devices at an actual match. So, imo, if they were effective, I'm sure every competitor would have one. My thinking is if you don't let the barrel get too hot, then you don't have to worry about it.

Quigley poured water down the bore of his Sharps, but that may have been to clean it rather than cool it.

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Quigley poured water down the bore of his Sharps, but that may have been to clean it rather than cool it.

I have a 22-250 that has had water run through the barrel on several PD trips.

Personally I use a three-second rule. If I can't put my palm on the barrel and hold it for three seconds (*without burning myself or letting go), it's too hot.

I am at a loss of this.

Years ago, I had a Ruger 77 in 220 Swift, that shot very well.

I had loaded several hundred rounds, and put them in a military metal ammo box.

We were camping in the desert, and while I was away, my brothers and friends shot the whole lot in one sitting.

When I came back I found this, and apparently they shot all the ammo in one sitting!!

That rifle never shot any decent groups after that.

We have a rifle here I built myself. It is a 308 Winchester, built on a Remington 700 action and has a Hart match barrel.

It is used by everyone who comes to shoot here, and on some occasions they only stopped shooting it because they could not see the target well enough because of the heat waves over the barrel.

It is mostly shot with military ammo, and the inside of the barrel looks like an elephant skin, especially just ahead of the chamber.

I would estimate this rifle has fired at least 60,000 rounds.

Last year I tried a few match loads in it, and it still shoots less than an inch!!?

Saeed, that may have something to do with the round being shot. I remember an article in Shooting or Shooting Times a long time ago that discussed the subject of the 308 and the estimate was something like 50,000 rounds given safe pressure for the 308 to show much effect. I believe it had to do with case size and capacity in relation to the bore. But I am getting old, so my memory could be wrong.

Barrels are like car tires, they start to wear out as soon as you start to use them. Peel-out and burn rubber or come to a screeching halt at every stop sign will wear those tires out fast, but take it easy and keep them cool, start and stop slowly, those tires wear much longer.

Same is true for barrels - they wear-out faster with hot loads (especially from overbore guns) and running hot barrels.

What's the rush - take it easy and shoot another gun while the other cools down. Limit the hot loads to hunting season only.

Great analogy!

quote:

Originally posted by Blacktailer:
I've always followed the "If you can't hold your hand on it, let it cool" rule. But slightly off topic, What about full auto? Do M16's wear out barrels every day? I know some of the larger full autos are water cooled but what about smaller machine guns?

I have an AR barreled for 5.45mm Soviet which shoots ammo I paid $0.12 per round. I'll shoot 200 shots in an hour two or three times a month. I clean it with boiling water and tranny fluid. It gets so hot after the second magazine the tranny fluid smokes off. Now the barrel has 8000 rounds through it. Still shoots well, 20 shot group, 6 inches at 200 yards, typical for the type of rifle it is.

When the rifle is resting on the bags with scope on the target, if the barrel points at the ground, it's too hot.