How to know when to change barrels?

[Bbear]

I have a 1st year production 700 in 25-06 that has more than 3000 rounds down the barrel. The 'specs' call for a cartridge OAL to be 3.25". Currently, to reach the lands I'm at 3.45". Though accuracy is still good (sub-moa w/ 110 AB's & a couple of different powders) I'm wondering if it's time for this one to get a new tube?
Primary use is hunting but I also use it as a rifle to shoot while letting other rifle's cool off. I average about 400-500 rounds / year through it as it is.

So, when (and how to tell) do I need to swap the tube out?

 

[Mateo]

I was just discussing this with someone. What we decided was velocity takes a hit first. It will start to drop off as the bullet can't get as good a seal with all the fire cracking and burnt out rifling in the first little bit of the barrel. Some barrels can still shoot accurately if wear is even and the bullet isn't so sensitive to seating depth changes. But eventually even accuracy will start to drop off fast. If you aren't recording velocity , getting it bore scoped will tell you how far gone it really is in terms of fire cracking and rifling wear at the throat.
I had an old .270 win R700 that had a badly worn out barrel and it would sometimes shoot decent groups on paper in warm weather, but when cold weather hit it was all over the place. This was a mild load but a depth sensitive bullet.

 

[waspocrew]

I'm all for getting a new barrel, but I wouldn't worry about it until accuracy starts to suffer. Accuracy is an individual standard that you have to decide on. If the rifle won't hold up groups as tight as you'd like it to, then throw a new tube on. If the groups are still acceptable to you, keep firing away until you feel like it's time.

 

[Bbear]

Short update: Though still accurate, the velocity on the 110 gr. is down to 2800. My other 25-06 shoots the same bullet to a velocity just a smidge (that's a technical term ya know?) over 3100.

Previously, the barrel in question would shoot 120 Speers right at 3000.

I'm thinking I need to find someone with a bore scope to take a look. Odds are I'm not going to enjoy seeing what I find.