I've never had to replace a barrel. I'm not a prolific shooter so that may have bearing on it.

 

The need to replace a worn-out barrel is rarer than a Democrat who doesn't want to confiscate your guns, cut your kid's sex organs off, and give illegal aliens your property.

In other words, unless your barrel is damaged, you won't need to replace it.

 

Unless shooting precision target matches, a handgun barrel will remain serviceable for 100,000 rounds or more unless there is some form of breakage at a stress point, like a locking lug or something like a swinging link on a 1911.

 

The only barrel I had that required replacing was on my Auto Ordnance 1911. I built it from a kit in the late 80's. One day I was shooting it and the barrel link mount on the barrel broke. I have a couple of spare barrels and other parts for some of my more unique guns. But that's more like a buy it when you see it thing due to parts getting more scarce for them as time moves on. 1911 parts I can practically find walking down the side walk on any given Tuesday. So what I'm saying is that it's not bad policy to keep some spares on hand. But then again, I was a bit of a scrounger back during my Cav days so basically I haven't changed since I got out.

 

I figured it was rare and I figure I shoot I might never get to 10,000 in each of my guns but remember reading or viewing something about this and wondered if it was an issue I'd really have to worry about in my lifetime - other than some weird breakage or damage. It sounds like from normal wear and tear from shooting the gun it might be a rare occurence.

 

More barrels are ruined by over-cleaning, metallic cleaning brushes, improper solvents and polishing compounds, and excessive pressure hand loads than shooting factory ammo.

 

I had to replace a barrel on my S&W Model 29 after the forcing cone began to crack. But this was after shooting God only knows how many full power .44 Magnum loads out of it. The rest of the gun held up. Back then all I wanted to do was go out and make a lot of noise and feel the concussion and muzzle blast of that big ole' 44 course through my body. While blowing away all types of things from unopened shit beer cans to abandoned cars. That being said it's highly unlikely that you'll have to replace a barrel unless you want to. What I did with that gun was not normal wear and tear. It was bordering on abuse. It originally came with an 8 3/8ths inch barrel and I swapped it out for a 4 inch.

 

Yes, barrel break, wear out, get damaged through normal wear and tear. If you have a question about your barrel, maybe take it to a competent gunsmith and ask for an inspection.

I have a 1943 M1 Carbine. Went through WWII, the Korean War, and who knows else. The barrel is now out-of-speck -- 0.01 or 0.001 more in diameter than when it was made. I plink with it so it doesn't matter to me but if I use it for competition, I would re-barrel it or buy a new manufacturer. If I do want a shooter at any point, I will go to Fulton Armory, for example, for an original receiver with target/competition barrels.
Glock, with the hexagonal barrel, can't shoot lead regularly. Replacing with a traditional barrel means you can.
The barrel's crown can become damaged from drops and improper cleaning.
There is a lot that goes into making a competition gun. One is a competition which factory Glocks don't have as a rule.