What really causes a barrel to wear out...

I don't think that a barrel will be worn out after a predetermined number of rounds.

Barrel wear is caused by Use and abuse. Everyone has different uses and many different ways to abuse ANY barrel. So if someone tells you
that you wont get 500 rounds through it before the accuracy goes, what their realy saying is that they didn't get 500 rounds through theirs or they are just quoiting what someone else said.

If we practice not doing all the things that we know will damage a barrel, they will last a lot longer. I have freshened up barrels that have been abused one way or the other buy setting the chamber back one thread and they returned to previous accuracy.

The throat is abused the most and shows the problems faster that the rest of the barrel, this can be fixed or remedied in the first place and barrel life can/will be extended. the many reasons and abuses have been talked about many times on this site and if this information was followed this problem would be minimized.

Abuse comes in many forms and barrel life is dependent on the level of that abuse. some cartridges will wear the barrel out sooner than others but most of the differences lie in the practices, not the cartridge.

If I were to ask how many rounds you could fire in a 308 before accuracy went away the numbers would vary a great deal from one person to another, So where is the lies difference from one 308 rifle to another 308 rifle.

Again: my opinion is "Use and Abuse"

J E CUSTOM
 
I don't think that a barrel will be worn out after a predetermined number of rounds.

Barrel wear is caused by Use and abuse. Everyone has different uses and many different ways to abuse ANY barrel. So if someone tells you
that you wont get 500 rounds through it before the accuracy goes, what their realy saying is that they didn't get 500 rounds through theirs or they are just quoiting what someone else said.

If we practice not doing all the things that we know will damage a barrel, they will last a lot longer. I have freshened up barrels that have been abused one way or the other buy setting the chamber back one thread and they returned to previous accuracy.

The throat is abused the most and shows the problems faster that the rest of the barrel, this can be fixed or remedied in the first place and barrel life can/will be extended. the many reasons and abuses have been talked about many times on this site and if this information was followed this problem would be minimized.

Abuse comes in many forms and barrel life is dependent on the level of that abuse. some cartridges will wear the barrel out sooner than others but most of the differences lie in the practices, not the cartridge.

If I were to ask how many rounds you could fire in a 308 before accuracy went away the numbers would vary a great deal from one person to another, So where is the lies difference from one 308 rifle to another 308 rifle.

Again: my opinion is "Use and Abuse"

J E CUSTOM
Great stuff!
The whole thing really interests me a lot. It got me thinking about why the differences. Why do some cartridges toast barrels faster than others? The heat from a 300wm cartridge is the same as a 308 isn't it? The temperatures are likely similar. We generally except that overbore cartridges kill barrels faster, all things being equal. Pressure has got to play a big role.

Disclaimer: I'm not an expert and this is not "my" theory. I came across this video and found it very interesting stuff.
 
Interesting! Case in point, if I hadn't had to make some new 7STW cases, the cases would come out dented in the shoulder area (that never happened before), stopped and looked at the chamber with a scope, there was no throat, leade or rifling, it was a musket for 5-6 inches! Now, it still shot with good accuracy with previous ammunition, but it was overdone! If I had never had to make new cases, I never would have suspected, that much wear.
 
Saw a report from a well known barrel maker who told new buyers to use a break-in process that used 100 rounds. When ask why his reply was he mostly sold to bench rest shooters who replaced barrels after 3000 rounds. So he sold more barrels if the shooter followed his directions for break in.

I have a Russian WWII rifle that was manufactured in 1936 that has a very clean barrel and still shoots very well.
 
Pretty clear within a few minutes the video poster is not an engineer or physicist.

If you don't even understand the dimensions of the units you are discussing, the best thing to do is stop trying to fake the physical engineering models and just share observations and measurements. Sorry if that is offensive, but it isn't meant to be hostile. The internet has too much pseudo-science and vulnerable folks can't sort through it. This is a technical forum so we owe it to each other not to mix BS and opinion with engineering.
 
So if he is right then if I had a barrel that is 30" wall thickness then it would never have fire cracking... I don't think so!
He is dead wrong about heating/cooling cycles not causing micro fissures.
Amazing how many people are going to believe he has the answers.
 
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!

Curious if this leads us up the barrel.....
Since the freebore is smooth...it allows all th metal full heat as cartidge is fired....
If the freebore was slightly riffled or rifled would the freebore be able to redirect the heat into the barrel better....making a little more pressure for the bullet to travel faster.....
It's a concept to refine freebore erosion....
 
I am a bit amazed at the stories of burning out barrels with the exception of abuse, which makes sense and those shooting round after round for whatever reason, like competition. It's just that I have rifles made since 1950 and I don't think any have shot even near their lifetimes yet. I guess it's nice to spread your shooting around, from firestick to firestick and we're blessed to have dry air here in CO.
 
Does the front of a chamber ever get cracks? I suspect there is more expansion and contraction, from pressure, at the front of the chamber than there is in the throat.
 
The amount of pressure-caused expansion is proportional to the section of the chamber walls. There is a dynamic change as the projectile travels away from the chamber since the pressure volume is the chamber plus the volume behind the bullet. The chamber neck has a layer of brass that is exposed to the powder and plasma, so it does see the pressure but there is a big difference in the heat at the surface when comparing the leade and the inside of the case neck.
 
I don't think that a barrel will be worn out after a predetermined number of rounds.

Barrel wear is caused by Use and abuse. Everyone has different uses and many different ways to abuse ANY barrel. So if someone tells you
that you wont get 500 rounds through it before the accuracy goes, what their realy saying is that they didn't get 500 rounds through theirs or they are just quoiting what someone else said.

If we practice not doing all the things that we know will damage a barrel, they will last a lot longer. I have freshened up barrels that have been abused one way or the other buy setting the chamber back one thread and they returned to previous accuracy.

The throat is abused the most and shows the problems faster that the rest of the barrel, this can be fixed or remedied in the first place and barrel life can/will be extended. the many reasons and abuses have been talked about many times on this site and if this information was followed this problem would be minimized.

Abuse comes in many forms and barrel life is dependent on the level of that abuse. some cartridges will wear the barrel out sooner than others but most of the differences lie in the practices, not the cartridge.

If I were to ask how many rounds you could fire in a 308 before accuracy went away the numbers would vary a great deal from one person to another, So where is the lies difference from one 308 rifle to another 308 rifle.

Again: my opinion is "Use and Abuse"

J E CUSTOM

So it's the "NUT" behind the trigger is the culprit.
 
So it's the "NUT" behind the trigger is the culprit.


Most of the time.
When someone brings a rifle to be re barreled it is quite easy to see the abuse with a bore scope and a head space gauge especially when you hear the round count.

I often find bolt lug set back, fire cracking and other signs of over pressure loads and erosion from primer failure. I was once afflicted
with the hot load sickness and it brought me nothing but problems and short barrel life. After seeing the errors of my ways I have not destroyed a barrel sense.

Just my experience with barrel life. There can be much more usage in a good barrel if all of the known reasons for poor life are avoided.

J E CUSTOM
 
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