If you are going to go to the trouble of going with an AI 243 and fireforming the brass, and expect to shoot heavy for the caliber VLD's, then I think you are wasting your time with a short barrel.
It would seem to be defeating the object of spending all that money and time building a custom rifle
. Because the factory rifles like the model 12 or 10 will shoot the other bullets you are talking about just fine, all the way up to 95gr, provided you stick to the shorter 95gr hunting VLD which is designed for a 10 twist.
But if you want to shoot the 105's or possibly 115 VLD's then you will need the extra capacity of the ackley case and the custom 8 or 7.5 twist barrel for sure and slower powder and that means that a long tube is best for developing maximum velocity.
I am very satisfied with my model 12 and its Shilen 26" varmint barrel. Back calculating from my 100-300 yards bullet drops, I am sending a 95gr (long) VLD downrange at 3400fps while fireforming my brass. So I am not even into ackley charge weights yet. Yes, it is a heavy gun, with the long barrel, laminate stock, steel one piece rail and vortex scope + 27" bipod but I'm not doing spot and stalk...