How to tell if your barrel is burned out

[Article 4]

I am asked sometimes how often I change barrels or how do I tell when a barrel is getting past its prime or even burned out. Here is how I keep track and think about barrel burn;

Am I seeing random POI Shift and inconsistent flyers?
Big Velocity differences - perhaps gaining velocity
Changes in SD and ES that are inconsistent or perhaps speeding up

If I am, my process is to take a look at:

• Round count....easy if you buy a new barrel and can track as you shoot. If I am near expected bbl life for that round, I have ordered another bbl already. Not as easy if you buy a used rifle.
• Check all torques – is everything mounted and torques to spec (from brake to action screws and everything in between)
• Check scope tracking - every scope fails at some point...is this one failing?
• Check bbl tightness – rare occurrence but it can happen

If that all checks out, I will then do:

• Deep cleaning – firing pin assembly, chamber, bbl
• Full Ammunition inspection - hand loads are easy cause I know the specs and did I make some errors in loads?
• Re-verify jump
• Bore Scope your throat and bbl for erosions (including pics of the extremes - (fresh cut chamber with round and extremely abused and eroded throat which is usually the culprit especially with high velocity mag rounds)

I am sure I didnt think or check everything but that is my process and it works pretty well for me

 

[Nine Banger]

When you fresh cut a chamber, are you just bumping it forward with the new cut and removing some material from the back of the barrel, or is it more involved? Or did I miss the point and you just meant you notice that's the issue and toss the barrel?

 

[Article 4]

When you fresh cut a chamber, are you just bumping it forward with the new cut and removing some material from the back of the barrel, or is it more involved? Or did I miss the point and you just meant you notice that's the issue and toss the barrel?

I am simply talking about running out barrel life and knowing when to change it versus it being some other accuracy issue

If you are going through a process of "setting in back" that is recutting a chamber on your current barrel, then yes, you are cutting about 1/2 inch +/- depending on caliber, off the back of the barrel and recutting the new chamber to achieve a "new" throat. This is not a complete new barrel - this simply extends the life of your current barrel

 

[Air Bear]

What factors allow or disallow “settling it back”? ie enough shank (if thhats the right term)? How much life can you expect from the “settling back”bbl? 100% of original, 75%?