When do you know the barrel is shot out?

[DalesCarpentry]

When do you know when the barrel is shot out? I have a Remington 700 SPS 243. I have only put about 150 rounds through it as of now. I was wondering how many rounds I could get out of this barrel? I would think the barrel is done when the groups start looking like patterns. Dale

[corbanzo]

It's whenever accuracy isn't good enough for you anymore.  For the normal shooter that is thousands of rounds, if not tens of thousands in some rifles.  Would be less for the BR shooter. 

I have rifles that have seen 2-3 maybe 4,000 rounds max, and still shoot well. 

[Mikey]

Dale - some barrels will 'pattern' for you after about 20 rounds but it doesn't mean they are shot out.  Many barrels said to be shot out turn out to become moa barrels or sub-moa barrels with a good cleaning and in some cases, lapping.  I would hazzard the guess that if you can't see that there is any rifling in the barrel and she patterns then she might be shot out.  The 243 is a fast mover but not so fast as to destroy a barrel in so few number of rounds.  I would think more in the thousands, and high thousands at that. 

[jvs]

The group will start to open up, and there won't be anything you can do to tighten it up again.

Key-holing will occur at 100 yds or less.

"Cotton-balling" will be evident when a bore scope is used.  More pronounced n Magnums.

The Crown will no longer be flat.

And burning out the rifling will be evident after loading maximum loads for a period of time.

I have one that is just about shot out after 0ver 30 years of dedicated use.  I probably have about 3,000 rounds thru it by now.  The crown is no longer flat, it has 'pushed out' about 1/8 inch.  I can gently push a bullet down the muzzle end about an inch, so I know something is happening.  'Cottonballing'  is beginning to happen at the Breech end.  So far it is not keyholing nor am I noticably losing accuracy.  But I know this barrel  is just about gone.   Maybe another 500 rounds or so.

When it happens you will notice.  Until then, don't push the reloads.

[KN]

I shot the barrel out of my 700VS in 22/250. Took just over 5000 rounds before accuracy got unbearable. My gunsmith said about 3" of throat was gone. If the throat isn't too far gone you can have the barrel set back for around $150. That may extend life a few more thousand.   KN

[DalesCarpentry]

Dale - some barrels will 'pattern' for you after about 20 rounds but it doesn't mean they are shot out.  Many barrels said to be shot out turn out to become moa barrels or sub-moa barrels with a good cleaning and in some cases, lapping.  I would hazzard the guess that if you can't see that there is any rifling in the barrel and she patterns then she might be shot out.  The 243 is a fast mover but not so fast as to destroy a barrel in so few number of rounds.  I would think more in the thousands, and high thousands at that. 

I am not saying mine is shot out. Heck it is still new and hardly broke in. I was just wondering how many rounds before it is. Dale

[30-30man]

You will probably never see it, you heirs will.  Often when I have had guns take south it is because the wood in the stock started swelling on me, the crown was damaged, or the scope mount/rings have come loose.  Enjoy it and clean it after every shoot, it will last your lifetime.

[DalesCarpentry]

I don't know about that. I shoot probably 1,000 rounds a year. Probably much more this coming year seeing as I just started reloading. I am pretty sure I will shoot it out at some point. Dale

[warf73]

I shot out my 22-250 barrel back when I was young(er) and really dumb. The rifle was well used when I bought it from the gun smith but he told me it only had 2k rounds left in the barrel. It took just over 1k but it was my own fault, I got onto a few Dog towns and shot till heat mirage took over and had to wait till the barrel cooled off(a barrel is beyond to hot when you can't see a Dog at 100 yards). Then did it all over again.

Now that I'm old and wiser in the ways of a rifle I don't do that anymore no were near that.

If you take care of the barrel it will last a life time, my 204 is closing in on 2k rounds and it the barrel still looks new.


Warf

[beemanbeme]

As posted, heat is your enemy. A little self control in your rate of fire will go a long way toward barrel longevity.  In my experience, there isn't one sad day when you say, "gee, my barrels shot out". The groups just open up a little with maybe an occasional flyer that is slightly out of the group.  You will probably never reach the day when the rifle doesn't meet hunting accuracy. So if you're looking forward to the day when you can have it rebarreled into a 7-08 or a .260, it's a long way away.
I was able to prolong the life of a 22-250 of mine by resetting the COL each spring and adjusting the powder charge over a Chrony since I only shot it single fire.

What is "cottonballing'??

[jvs]

Cotton Balling is not a technical term, but rather a condition of erosion of the throat of a rifle caused by max powder charges or Magnum loads.   

Erosion in the area of the bore where the bullet leaves the casing.

When you use a bore scope you will see the 'cotton ball' effect where heat has taken a toll on the bore that allows gases to escape around the sides of the bullet instead of mostly remaining behind the bullet and would be responsible for a loss of accuracy.

For the first couple of mm's of the bore beyond the casing and just a few miliseconds after firing, high heat and expanding gases continue to damage the bore in this area every time the trigger is pulled.  Even the best steel won't withstand some flaking of the bore caused by heat.  The problem is that this happens will less than magnum or hot loads, but at a much slower rate. 

More Powder = More Heat

More Heat = More Erosion

More Erosion = Loss of Accuracy Sooner.

 

[jro45]

When you fire say 10 to 15 rounds and they aren't in a nice group. The rounds have to be the kind your rifle likes also.  You'll know it cause it is something that rifle doesn't normaly do.

[Rangr44]

Most gun's internal barrel damage comes from rust/neglect, the second leading cause is cleaning rod wear, and the third is erosion - accelerated by constant hot loads and/or continual repeated rapid firings that super heat the throat area, washing out the leade/rifling.

No, you and I don't let our guns rust intentionally - but I've seen many, tossed under a porch by an ignorant spouse, that were rusted solid.

I've also seen clean-a-holics, stroking away at the bore, from both ends with a flexible cleaning rod, do more damage than if they never cleaned it at all.

If a barrel's shot until it's too hot to touch - it's been shot way too much, that string. Let it cool off.
Dedicated shooters often use a water cooling flush, made from an old, large fire extinguisher, to chill out the gun during mucho shooting - like a varmint safari.

[Brithunter]

Hi All,

    I see lots of advice and ideas here but one fact is obvious by it's omission. The choice of powder will effect the accurate life of a barrel!

    Some powders are more prone to barrel burning than others just as some cartridges are more prone to it than others. In this thread two catridges that are prone to throat burning, namely the 22-250 Rem and 243 Win, both of which are over-bore. It is not always high velocity as is often quoted but powder burning tempreture which causes the damage alied with pressure. Back in 1892 or so the British military found this out with the new, then smokeless, Cordite powder which burned the throats out of the Metford rifled barrels in about 1,000 rounds or even less. When you consider that the velocity of the 215 grain round nosed bullet was only around 2050 fps it prooves that high velocities are not required to destroy a barrel. Two tyings were done to lessen the problem and increase service life of the barrels.

    The Nitro Clycirine content was reduced in the propellant and the rifling form was changed from the "shallow rounded" Metford form excellent for black powder to another Metford design which came to be known as "Enfield rifling" due ot it's being adopted by the Enfield Lock government arsenal which had five grooves of square profile which tapered in depth from breech to muzzle. This switch increased the service life by about five fold however during certain trench exchanges of fire during "The Great War" the service life of a barrel was measured in days not the amount of rounds expended. Using rapid fire techniques taught during training the "Old Contempables" fired at such a rate that the opposing Germans thought they faced a Machine Gun battalion and not a battalion of riflemen!