What range and at what velocity do you need?
I think either is fine for cutting back. Historically, I would have said 308 given the larger diameter, but I think the difference in velocity loss is minimal.
Which do you like using better?
I think 16.5 is a good length.
The 6.5 has lower recoil and better long distance ballistics, it will maintain both of those in a shot barrel. While I currently have a 308, I want to rebarrel to 6.5 or 6 Creedmoor. That that would be my vote.
On the other end of things, the 308 recoils harder, so the suppressor will do more for improving shoot-ability.
Do you know your current velocity? If you have applied ballistics you can estimate the worse case range scenario from the velocity loss. If you do not have applied ballistics, provide the following information and I can give you an estimate (though both from a short barrel will get you to 400 yards easily unless you must use monos).
-Twist rate
-Bullet (needed expansion velocity if known)
-Altitude
-Current MV if known and current barrel length (worst case is loosing 50 fps per inch, usually you loose closer to 30 fps)
I think either is fine for cutting back. Historically, I would have said 308 given the larger diameter, but I think the difference in velocity loss is minimal.
Which do you like using better?
I think 16.5 is a good length.
The 6.5 has lower recoil and better long distance ballistics, it will maintain both of those in a shot barrel. While I currently have a 308, I want to rebarrel to 6.5 or 6 Creedmoor. That that would be my vote.
On the other end of things, the 308 recoils harder, so the suppressor will do more for improving shoot-ability.
Do you know your current velocity? If you have applied ballistics you can estimate the worse case range scenario from the velocity loss. If you do not have applied ballistics, provide the following information and I can give you an estimate (though both from a short barrel will get you to 400 yards easily unless you must use monos).
-Twist rate
-Bullet (needed expansion velocity if known)
-Altitude
-Current MV if known and current barrel length (worst case is loosing 50 fps per inch, usually you loose closer to 30 fps)