Shooting out a barrel...

[Rooster17]

I'm no long gun expert by any means so I apologize if this is a dumb question. I always see guys posting stuff about "shooting out a barrel." Obviously with time everything is subject to wear, but is this with all rifles? Like how about rimfires? Like .22 mag or .17 HMR? I'm just curious... Is there some type of round count with different calibers where accuracy will deteriorate or is this only with higher performance centerfires?

[xd ED]

"Barrel Burners" is the term applied to some cartridges. I'm no expert either, but generally, a high volume of powder/ bore diameter ratio will burn out the breach faster.
Accuracy will degrade. Some rounds I've read will do this in less than 1000 rounds.
One fix is shorten the barrel by cutting out the eroded chamber, and recut the chamber
As to the rimfires you mention- you should live so long or afford the ammo.

[Tronster]

In my limited knowledge, it seems alot about shooting out a barrel comes down to how fast the bullet travels and how much erosion the powder burns at the throat. It seems the super high velocity varmit caliber rifles that are approaching 4000 fps are burning out the barrel in as few as 1000 rounds simply due to extreme friction, but a slower caliber could last 10,000-20,000 rounds. Pistols are often in the multiple 10K round counts, simply because a pistol cartridge doesn't burn as much powder and velocity per round as a rifle round.

[photogpat]

You and I likely can't burn out a rimfire barrel like xD Ed said. Won't be able to shoot enough rounds fast enough.

Lead it up pretty badly sometimes...but that brushes out.

[jshuberg]

As a general rule most barrels are damaged by excessive and improper cleaning more than they are from being fired. Because of this, it's incredibly difficult to predict when barrel wear will effect accuracy.

I'm sure that others will chime in with greater detail, but there are several factors that contribute to barrel wear. Friction, heat, and metallurgical changes that happen in the bore due to extreme temperature and pressure. Letting the bore cool to room temperature after each shot will extend barrel life, but isn't always practical depending on what you're doing.

Generally speaking, rounds that produce lower temperatures, lower pressures, and less fouling will do less damage to the bore. Under extreme temperatures and pressures microcracks will form in the bore, and carbon will be introduced into the steel structure, making the first few microns of the surface of the bore considerably more brittle than the original steel. Mechanical cleaning with a brush can then accelerate erosion of the bore by removing the protective layer of fouling and removing microscopic amounts of the brittle surface of the bore.

For rifle barrels, it's best to allow the barrel to foul, and then maintain a fouling equilibrium in the bore than to clean the bore down to metal after each usage. Both barrel life and accuracy will be increased by doing so, as well as minimize the possibility of damage by over cleaning. A dry boresnake a few times through the barrel after each use will prevent the fouling from becoming excessive, and a few patches and a nylon brush every 1000 or so rounds is fine. Only use a copper solvent when you notice a discoloration, or otherwise identify copper fouling at the crown.

Probably not what you wanted to hear, but I hope this helps.

[Rooster17]

As a general rule most barrels are damaged by excessive and improper cleaning more than they are from being fired. Because of this, it's incredibly difficult to predict when barrel wear will effect accuracy.

I'm sure that others will chime in with greater detail, but there are several factors that contribute to barrel wear. Friction, heat, and metallurgical changes that happen in the bore due to extreme temperature and pressure. Letting the bore cool to room temperature after each shot will extend barrel life, but isn't always practical depending on what you're doing.

Generally speaking, rounds that produce lower temperatures, lower pressures, and less fouling will do less damage to the bore. Under extreme temperatures and pressures microcracks will form in the bore, and carbon will be introduced into the steel structure, making the first few microns of the surface of the bore considerably more brittle than the original steel. Mechanical cleaning with a brush can then accelerate erosion of the bore by removing the protective layer of fouling and removing microscopic amounts of the brittle surface of the bore.

For rifle barrels, it's best to allow the barrel to foul, and then maintain a fouling equilibrium in the bore than to clean the bore down to metal after each usage. Both barrel life and accuracy will be increased by doing so, as well as minimize the possibility of damage by over cleaning. A dry boresnake a few times through the barrel after each use will prevent the fouling from becoming excessive, and a few patches and a nylon brush every 1000 or so rounds is fine. Only use a copper solvent when you notice a discoloration, or otherwise identify copper fouling at the crown.

Probably not what you wanted to hear, but I hope this helps.

Actually considering I just bought a bore snake and a nylon brush for my .17 HMR it helped a lot. I hate to admit it, but like a moron the first time I cleaned my .17 I was putting the cleaning rod down the wrong way! OOPS at least I only did it once! Before this rifle I had only owned shotguns and revolvers so I didn't know better. Accuracy still seems great though. I wonder how much that affects a gun.

[jshuberg]

It's hard to say, but I don't think one improper cleaning will do much harm. As long as you weren't dragging the rod across the crown you should be ok, just don't make a habit of it. The crown is the most sensitive part of the barrel. Uneven wear or scratching can result in a non uniform pressure being applied to the bullet at the moment it leaves the barrel, increasing the distance in the air the bullet will travel before becoming fully gyroscopically stabilized. The further from the muzzle the bullet becomes fully stabilized, the greater the potential for the bullet to wobble and drift slightly, lowering accuracy.

If you feel your crown may have been damaged, you can have it inspected and re-crowned if necessary, but one muzzle cleaning on a new rifle should be fine.

[xd ED]

As a general rule most barrels are damaged by excessive and improper cleaning more than they are from being fired. Because of this, it's incredibly difficult to predict when barrel wear will effect accuracy.

I'm sure that others will chime in with greater detail, but there are several factors that contribute to barrel wear. Friction, heat, and metallurgical changes that happen in the bore due to extreme temperature and pressure. Letting the bore cool to room temperature after each shot will extend barrel life, but isn't always practical depending on what you're doing.

Generally speaking, rounds that produce lower temperatures, lower pressures, and less fouling will do less damage to the bore. Under extreme temperatures and pressures microcracks will form in the bore, and carbon will be introduced into the steel structure, making the first few microns of the surface of the bore considerably more brittle than the original steel. Mechanical cleaning with a brush can then accelerate erosion of the bore by removing the protective layer of fouling and removing microscopic amounts of the brittle surface of the bore.

For rifle barrels, it's best to allow the barrel to foul, and then maintain a fouling equilibrium in the bore than to clean the bore down to metal after each usage. Both barrel life and accuracy will be increased by doing so, as well as minimize the possibility of damage by over cleaning. A dry boresnake a few times through the barrel after each use will prevent the fouling from becoming excessive, and a few patches and a nylon brush every 1000 or so rounds is fine. Only use a copper solvent when you notice a discoloration, or otherwise identify copper fouling at the crown.

Probably not what you wanted to hear, but I hope this helps.

Actually considering I just bought a bore snake and a nylon brush for my .17 HMR it helped a lot. I hate to admit it, but like a moron the first time I cleaned my .17 I was putting the cleaning rod down the wrong way! OOPS at least I only did it once! Before this rifle I had only owned shotguns and revolvers so I didn't know better. Accuracy still seems great though. I wonder how much that affects a gun.

The hazard of cleaning from the muzzle is nicking the crown with the cleaning rod, or I suppose if done excessively, the crud- soot, etc, which can be abrasive to steel, could wear the rifling at the crown.

[OldmanFCSA]

All of the above is true for most rifles.

However, for the 50BMG target rifles I shoot, most of the wear to the throat, and first couple of inches of bore, is extremely "shot-out" by the abrasive action of 250 grains of powder being pushed by burning powder behind it. We have had many discussions on proper cleaning techniques, the use of SS brushes in the bore vs brass brushes, using bore solvents to remove carbon or copper, or using 33% aqueous ammonia/soap mix to dissolve all copper and brass in the bore (this stuff eats brass brushes and brass accessories before the bore is clean). We at the FCSA have determined that powder erosion will damage a barrel more than any SS brush ever will. After a good cleaning these rifles need to be fouled before shooting the best groups, some with 2 to 5 copper projectiles, some with 10 plus rounds when using brass solids.

Moly should not be used on any rifle that is not cleaned every 5 to 10 shots as the moly will form a carbide buildup in the throat which will be very hard to remove.
I am experimenting with brass solids coated with titanium disulfide which is baked on the surface and does not rub off like moly. It is reportedly 4 times more "slippery" than moly. Due to reduced friction in the bore, a larger than normal powder charge is required for best performance. I am trying to push these 808 grain solids about 2900 fps or better from a 34" barrel.

22LR barrels cannot be shot-out, just not cleaned enough to remove the lead fouling which makes it look smooth inside and affects accuracy.

[OldmanFCSA]

The following was just copied from the FCSA Forum. It applies to this conversation topic:


As for one direction that to is a matter of personal preference Lee R has proved that short stroking a SS brush does no damage in either a SS or Chrome Moly barrel for what it is worth .

Oh Very important Never Ever use a Teflon or PETFE bearing oil in the barrel it goes inter granular and continued applications fuse , building up and Will ruin your barrel because there is No way to remove it short of Hydrofluoric Acid and it will eat the metal before it even touches the Teflon/PETFE Randy Deirks got a rifle back that went from Match winning to shotgun , he was pulling strings of Teflon out of the barrel 2' long and had to tell the owner the barrel was a total loss !!

Keep Teflon/PETFE out of the Hot portions of your rifle or you will pay the price CLP Breakfree ,Rem oil are a couple of oils you should avoid in the barrel ,Read the label carefully !

[LumberZach]

My uncle was telling me about a study one of the major bullet manufacturers did (Nosler maybe? I don't remember and haven't gone finding it yet) that proved that barrels are worn out by a specific about of powder usually measured in lbs. of powder. Now in addition to that I just read a magazine review where they took 4 identical ar-15's and fired 10,000 rounds of various ammo through each and documented the findings and the steel case ammo was key holing really (the chrome lining was worn all the way out) but federal was still marginally acceptable. I will try to find these tomorrow if I get time. It can be done, but it usually takes a long time. The 10,000 round study worked out the math and found the savings from steel case ammo actually more than covered the cost of a new barrel.

[jshuberg]

I believe you're referring to steel jacketed, not simply steel cased. If all you care about is cost, and don't care about quality, accuracy, reliability, etc. it may be correct that using the lowest quality ammo you can find will pay for a new barrel. My advice - don't be that guy.

[farmerj]

I'm no long gun expert by any means so I apologize if this is a dumb question. I always see guys posting stuff about "shooting out a barrel." Obviously with time everything is subject to wear, but is this with all rifles? Like how about rimfires? Like .22 mag or .17 HMR? I'm just curious... Is there some type of round count with different calibers where accuracy will deteriorate or is this only with higher performance centerfires?

What are you considering "shooting out a barrel"?

For a competitive shooter, when the groups matter, seeing a slight chance in accuracy, the barrel is switched out. That might be 1500-2000 rounds on a high quality barrel. For a typical hunting rifle, that barrel probably has thousands of rounds left in in.

For a machine gun. We are talking an actual m249, m240 type and m2 browning .50 cal. As well as others, their barrels have special linings to address the issue of bore and throat erosion from rapid fire. Rapid fire from the heat created, erosion of powder and powder burn destroy a barrel incredibly fast. I have seen barrels burned out in 2-3 uses because barrels weren't switched out. Its fun watching the accuracy fail. The bullets go from a line to a cone when you watch it with tracers.

Then you have the issues of overbore rounds. As i understand it, that's a ratio of bore size vs case size. The worst offenders being the super short magnums. The flame fronts from these burn barrels quickly. Even the .243 is much worse than the .308 because of such a much smaller bore.

http://www.accurateshooter.com/technica ... y-formula/
Then you get into the one that will start all the flame wars. Cleaning. Segmented rods are the devil on crowns. Nylon and nylon coated product right behind them because the plastic is that abrasive as well as it collects debris and makes it worse. Solid metal rods are best but try for a softer material than the barrel.

Muzzle or chamber end? Some actions don't let you clean from the chamber end. Take you pick. But just get yourself a muzzle guide if you clean from the muzzle first.

More damage is done to accuracy by ticking the crown while cleaning than any shooting ever will.

[Erud]

Your rifle is probably just fine after one cleaning from the muzzle as long as you didn't get too crazy. Start cleaning it from the right end and use a bore guide and you will be ok. Personally, I don't like bore snakes as they pick up lots of crap which then gets dragged back through the bore on the next pass. I generally only use patches with caliber-specific jags for cleaning(no brushes), and clean after every use. Some guys will let their barrels go for hundreds or thousands of rounds before cleaning, and more power to them. The reason I don't subscribe to this practice is that every barrel will have a point where it is "too dirty" and starts to shoot poorly. It is very hard to know what that magic # of rounds is without actually reaching it. Fully cleaning a rifle that has had 1000+ rounds through it since the last cleaning will likely result in very different shooting characteristics when you take it back out to shoot. I know how my rifles shoot when they are clean, and I know what it takes to get them properly fouled again.

For me, a barrel is shot out when the X-count starts to drop at the longest range that particular rifle is used at. At that point it either gets replaced, or relegated to short-course duty. For the cartridge I shoot the most of, the 6mm Turbo 40°, that is about 3000-3500 rounds of top accuracy with a top-shelf barrel. For my .308's shooting extremely hot loads, it's about the same. I don't really shoot much .223 anymore, but my experiences with that were also pretty similar, probably a little closer to 4k. These barrels will still shoot well(sometimes VERY well) at shorter ranges, but they are past their prime. I keep spares on hand and reamers for the rifles that get shot a lot, as shooting out a barrel and having to wait months for the next one is not good.

I don't have any firsthand experience with .22wmr or .17HMR, but I'd expect that both would have pretty good barrel life due mainly to the amount of powder they burn and relatively slow velocities. I do know that the average human will generally not be shooting out .22lr barrels unless they are on their way to the Olympics or are involved in some other very serious competitive shooting. It takes a lot of soft lead bullets at 1100 Fps to wear down steel.

[Deputyhiro]

So.... How does breaking in a barrel play into this? I understand that you are suppose to clean after every round while breaking in a barrel, to season it, and close the pores? Is this correct? Seems everyone has a little different opinion on how / when you are suppose to clean a rifle barrel. And that over cleaning can be bad. Does this not apply while breaking in?