Throat Erosion from Not Allowing Barrel to Cool

The bore diameter has a big part of it. I've not seen to many 30cal eat the throats up other than the ultra mag. If you have an overbore high volume case your going to burn it up faster. It definately won't help your rifle but im your not going to kill it in 20 rounds either. I shoot my 300 in a prairie dog shoot. 16 targets from 200-600 yards timed. So you shoot fast. Fastest time and least number of shots win

The incandescent plasma and erosive power of the burning powder from each shot don't care that much about how fast you pull the trigger.

Heavy firing schedules (think full auto) will cause faster erosion, but most of it is bore size, velocity, and powder (single base, double base, and triple base), plus there are some anti wear additives that can reduce barrel erosion.

But generally speaking, barrels are a consumable item, just like powder and primers.

BSW

20 rounds in 20 minutes

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This is slow fire to me!

Barrel life is inversely proportional to powder flame temperature and pressure.

Higher pressures and temperatures lead to shorter barrel life.

Sustained elevated temperatures doesn't help, but generally you have to keep the barrel pretty hot, (above 500 F or so) to see any major difference.

I run my 300 win mag hard. I only get 3-4 maybe 5 loads out of my brass. But I've always like using a slow for caliber powder like retumbo. Fill the case and crunch a bullet!

Cowboybebop,

What you are describing (20 shots in 20 minutes) pretty much describes what is found in F Class Competition. With a lightweight fluted barrel chambered in 300 Win Magnum, you can expect very short barrel life. At the end of 20 minutes that barrel will be VERY HOT! I would expect accurate barrel life to be 1,000 round or less. Hope that helps.

Don

One man's worn out barrel is another mans shooter. It's common to hear of precision shooters documenting a .25moa increase in a group after a few thousand rounds, so they rebarrel.

The gun was a .5moa or less shooter in the first place. It's still shooting under 1moa but they replace it.

On the other hand, a rental range in Vegas goes 200,000 rounds a year in their top rental guns - and it's all full auto, every magazine. But, it's usually just one or two mags a trip out to the firing line and back again. As long as the gun hits the targets and the customers are happy, its a working barrel and good to go.

Military standards will keep a barrel in service until it hits the 4 to 8moa range in use in a combat zone.

What kind of results are expected determines if it's "shot out."

Ask the rifle.

First of all, after a string of fire, test barrel temperature. If it's above 100 degrees F, that's probably too hot.

Secondly, find someone with a bore scope and check the throat -- see if it's eroded or advanced.

In the absence of a bore scope, load a few dummy rounds, unsized, with the bullet held in place by a bit of toilet paper. Load the bullets WAAAAY out so they touch the rifling and are pushed back in the case as you close the bolt. Chamber one of these, and keep it as a reference round. Measure the OAL and write it down.

Over time, chamber the other rounds -- say one after each five shooting sessions -- and see if they have a greater OAL. When you get a noticeably greater OAL, you are getting throat erosion.

Those who are concerned about there barrels overheating may be interested in this item: http://barrelcool.com/
I've ordered a couple and have received them but have not tried them yet.

wahsben said:

Those who are concerned about there barrels overheating may be interested in this item: http://barrelcool.com/
I've ordered a couple and have received them but have not tried them yet.

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When you try them post with how well they worked for you. Not very expensive and not much to the little devices. Have some travel plans next week but when I get back I may order a few just to see how well they really work.

I recently measured a heavy barrel shooting .223 Remington. On average one round every 45 to 60 seconds. Ambient was about 73 degrees F. Within about 10 rounds the barrel was in the mid 90s and after 50 rounds was still mid 90s. However, the same rate with .308 and after 10 rounds while I didn't measure the barrel was too hot to touch.

As to erosion? Never gave it much thought with the .30 caliber bullets but the small diameter hot rounds like 22-250 seem to eat barrels pretty quick.

Ron

When shooting BPCR silhouette, it is usual to cover the barrel while targets are being reset if the firing line is in the sun. And for sure keep your ammo covered.

most of the summer, the barrel will be over 100* just from sitting on the ground in the sun.

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Which is why neither barrel nor ammo should be left in direct sunlight -- as the British found out the hard way, back when they used Cordite.

wahsben said:

Those who are concerned about there barrels overheating may be interested in this item: http://barrelcool.com/
I've ordered a couple and have received them but have not tried them yet.

Click to expand...

11F cooler after 10-14 min according to their own numbers . . . I'd keep the money and range bag space for something else.

Mike

If the car is parked nearby, after each ten rounds just put the rifle inside your car in front of the ac vents for two minutes.

First of all, after a string of fire, test barrel temperature. If it's above 100 degrees F, that's probably too hot.

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I live in South Carolina. There will hardly every be a time when the barrel is not over 100 degrees.

Reload Ron, I don't have any measuring equipment for this but will let you know what I think about them when I try them.

Arizona_Mike said:

11F cooler after 10-14 min according to their own numbers . . . I'd keep the money and range bag space for something else.

Mike

Click to expand...

According to this it cools better than that as far as cooling it off faster.There is probably no way to cool off a barrel fast without damaging it so this should be better than just letting it cool by itself. It is not that expensive and they include the batteries and it also acts as a safety flag in the action.

http://barrelcool.com/index.php/about-us-2/

wahsben said:

According to this it cools better than that.http://barrelcool.com/index.php/about-us-2/

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No, according to that is does exactly what I said. The difference at 10 and 14 min was exactly 11F.



Mike

Hello Highroad. I am the creator of BarrelCool and I wanted to chime in and answer any questions you may have and comment on the graph. When looking at the graph, it is not so much the temperature, but the time difference. It takes about half the time for a barrel to cool to the same temperature while using BarrelCool versus not using BarrelCool. So, for the barrel to get to 105 degrees, it takes about 20 minutes without BarrelCool and ~11 minutes with BarrelCool. The temperatures are also measured on the outside surface of the barrel temperature. This is also in a 1.25" straight contour barrel. In lighter contour barrels, the results are much faster as the 1.25" diameter barrel tends to retain heat more. This graph is probably the worst case scenario as far as barrel contour goes for most shooters.

Because BarrelCool is using ambient air, cooling will not be instant. This is arguably better for the barrels as others have mentioned. What I can tell you is that cooling effects relative to a barrel simply sitting as-is are significant around the 10-30 minute range, which is what most shooters experience either during a cease fire period at a range (because it acts as an empty chamber flag, it can now be used during cease fires at ranges that require chamber flags), in between strings or relays during a match, or while rotating through rifles while varmint hunting. As time increases, the curves will eventually converge, but that convergence would not occur for quite some time (this was not measured as we expected it to be greater than an hour). In F-Class barrels, a 25 round string could take an hour or two to cool. At a recent F-Class match, a person shooting a 7 RSAUM fired 25 shots and you could not touch the barrel for more than a second or two. BarrelCool was put into the gun and within 30 minutes, the barrel was near ambient. Without BarrelCool, this would have taken more than an hour if not more. This was under a shaded line and 85 degree temperatures.

There was a recent article created about Barrelcool, which has a lot of good information and shows actual field reviews showing the performance of BarrelCool. Link below.
http://bulletin.accurateshooter.com...amber-flag-fan-device-cools-down-hot-barrels/

-Bryan