What really causes a barrel to wear out...

[odoylerules]

This is a highly debatable topic I know. And I believe there is a lot of misunderstanding about the subject out there. This guy makes an extremely convincing argument that flies in the face of the commonly excepted theories on the subject.
I know the video is a little long, but you won't regret it. I learned a lot.

 

[MudRunner2005]

What really causes a barrel to wear out is simple. Even though the copper jacket is much softer than the steel barrel, you add velocity, heat, and friction into the mix, and that's what eventually wears out a barrel's bore. Direct heat and flame is what destroys a throat...Eventually fire-cracking and smoothing it to a point that it's out of shape and no longer holding the bullet properly as it's entering the rifling.

 

[odoylerules]

He theorizes that the real culprit is pressure. You can stick a flame from a torch to barrel metal or grinder to simulate friction, and neither will cause fire cracking. Only high pressure accompanied by the heat will do it.

 

[MudRunner2005]

He theorizes that the real culprit is pressure. You can stick a flame from a torch to barrel metal or grinder to simulate friction, and neither will cause fire cracking. Only high pressure accompanied by the heat will do it.

Pressure itself will not cause erosion, if so, every air compressor tank in existence is in danger. Pressurized heat/flame, absolutely can cause erosion...Look at how a plasma cutter works.

 

[odoylerules]

That's why I said pressure "accompanied by heat". Did you watch the video? I'm just trying to stimulate thinking because im fascinated by all this.

 

[NEMTHunter]

Heat alone will cause cracking. it causes very time hair line surface cracks. Any one that runs a torch on steel will know that it can happen even in as few as a couple heat cycles. Now do it hundreds of time and what will you have? Then throw a bullet running down the barrel as its doing it and barrel wear makes sense.

Why does the barrel not crack or erode the full length of the barrel? But the main erosion as at the throat? Not to mention why are some powders worth then others. And why are Overbore cartridges even that much worth? Even though they see the same pressure??

You can not blame it on pressure..

 

[TwoMore]

I know that there is 60000+ PSI cup pressure but is there that much in the barrel ? , I just cleaned up a 22-250 that has had a bunch of rounds through it and it has some significant heat cracking for about 12 inches or so , it was super dirty but after I cleaned it up it shoots lights out.

 

[TwoMore]

That's why I said pressure "accompanied by heat". Did you watch the video? I'm just trying to stimulate thinking because im fascinated by all this.

lol when I bought my hawk-eye some of the stuff I saw was like dang, how did that shoot!

 

[Orange Dust]

lol when I bought my hawk-eye some of the stuff I saw was like dang, how did that shoot!

I'm not buying one. I'm afraid if I did, I would feel the need to replace the barrel on every rifle I own. Could get kinda 'spensive...

 

[MudRunner2005]

With the innovation of technology and with tech prices dropping, people now have access to much more stuff. This allows average people to get their hands on previously unattainable equipment. This is allowing them to create their own manufactured stress by giving themselves something else to worry about.

If the gun still shoots great, doesn't excessively copper-foul, but the barrel and throat looks like crap inside, who gives a ****...

Personal opinion.

 

[Orange Dust]

With the innovation of technology and with tech prices dropping, people now have access to much more stuff. This allows average people to get their hands on previously unattainable equipment. This is allowing them to create their own manufactured stress by giving themselves something else to worry about.

If the gun still shoots great, doesn't excessively copper-foul, but the barrel and throat looks like crap inside, who gives a ----...

Personal opinion.

With 'ya buddy

 

[Sflutes]

Actually it's real hard to wear out a barrel, what normally happens is you erode the throat.
The throat is eroded from the hot gasses of the burning powder. Cartridges that erode the throat sooner than others are ones like the 300 Win Mag, 220 Swift, etc. Large capacity cases with small bore diameters. (Small when compared to the size of the case)
Another part of the barrel that is subject to wear is the muzzle. It is normally worn by improper cleaning technique. GI's would often hastily clean their M1's with the steel cleaning rod and wear the muzzle end of their rifles out. (Of course their main concern was not the wear on the barrel it was staying alive)
There were concerns with barrel wear when corrosive priming was used. The corrosive salt would form and rust the barrel that would literally erode the rifling. (This normally would happen when barrels were not cleaned)
Often a worn-out barrel can be set back and rechambered and the crown recut. This often restores the rifle to good shooting condition. (Provided it's not full of rust or pitting)

 

[odoylerules]

With the innovation of technology and with tech prices dropping, people now have access to much more stuff. This allows average people to get their hands on previously unattainable equipment. This is allowing them to create their own manufactured stress by giving themselves something else to worry about.

If the gun still shoots great, doesn't excessively copper-foul, but the barrel and throat looks like crap inside, who gives a ----...

Personal opinion.

Agreed!!

 

[Greyfox]

I thoroughly enjoyed listening to the OP's theory! I have also wondered about what actually contributes to barrel wear. I have also noted-cracking in just about every barrel that I have considered "shot", and have made it a practice to monitor round count, BTO/seating depth, and fire cracking for the life of my barrels. For my fairly stringent standard of accuracy deterioration of .25-.5MOA, and .005" increase in seating depth, combined with fire-cracking visibly extending into the lands...if the barrel isn't already shot, it will be very soon. I have seen firecracking develop in the free bore section of the throat between case mouth and the lands very early in the life of the barrel(300-500rds) and not advance into the rifling until 2000+ rounds, with no prior loss of accuracy. This is the case right now with my 6.5x47 at 1600 rounds. It's been firecracked in the freebore section since 600 rounds and it hasn't advanced. It's still at .25MOA accuracy with no throat wear. I have often wondered why the fire cracking takes so long to extend into the rifling. I wonder if the OP's theory plays into this. Could the pressure max and heat at that point at the cartridge mouth, combined with the smooth surface of the freebore section, be more susceptible to stress/expansion...causing the early firecrscking Interesting stuff to ponder!