I've had quite a few Encore barrels and never found any to be less than able to handle full factory loads. In fact max handloads have never been a problem.
I have a friend that managed to crack an Encore frame at the hinge pin hole shooting way overpowered loads, the same barrel shot fine on a different frame with standard factory ammo afterwords.
This is a good warning to exercise some common sense or reasonable extra care. Had those same way-overloads been fired in a 'strong' and properly vented bolt action the results would have been quite different. A catastrophic fail with a "way over" load should be a warning that this design in one that should be held level below that are max for a much stronger bolt. Factory 308 type pressures. Failure is one thing, slow stress and wear is another.
Curious what the OP is thinking of for barrel length? Long and fluted? Or very long?