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?