mlebler, when you get you rig finished, I know where we can send some lead downrange a very long ways
It is great to hear so many educated opinions. These smiths have been there, done that but I would like to add a little perspective to the discussion.
I spent the early part of my rifle building with little money and many take off barrels from gunshows and other competitive shooters. With some luck, all of these barrels were reinstalled for a decent price AND all shot well.
But what is 'shot well'? For most shooters, varminters and hunters, having a rig that can shoot an honest 1/2 min is amazing. That is one big hole at 100yds. That's a milk jug everytime at 1000yds.
For a competitive BR match shooter, that barrel would be toast. An embarressment.
So I look at what the shooter wants to achieve with the build. If they are looking at competing at the highest levels, only the best NEW barrels need apply. Assembled by someone competent.
If they are looking at popping clays at 500yds (just slightly under MOA by the way), then a set back match pipe would be ideal.
For me, I can easily burn through a F class match barrel in one season.
For the average hunter, that number of shots is unlikely to be fired by several generations of shooters over all their lifetimes.
For a varminter, they can usually get twice as much barrel life as me because they usually aren't looking for my degree of accuracy/consistency.
So like everything else, it just depends.
As for needing to set back a 308, odds are you will have gone on to different things LONG before a 308 is worn. With an est lifespan of 5000rds, that is alot of shooting.
As for velocity, if you got fast pipes wonderful. However, I always caution shooters about accurate velocity as well as functional pressures.
Going really fast all over the countryside isn't much fun nor is locking up your action because of a change in ambient conditions.
Todays shooters can enjoy performance well above what was possible 15yrs ago. new powders are going to push these limits even further.
But there still remains the need to balance the performance with the intended application and rig that will be used.
There is no free lunch so be aware of the limitations/trade offs.
Jerry