From what I can see, the only difference between Shaw's barrel contours for the Heavy Magnum and the Varmint is the taper of the barrel.
At the start of each barrel upon shortly after having left the action is:
1.035 diameter for the Heavy Magnum
1.035 diameter for the Varmint
At the middle of each barrel is:
0.928 diameter for the Heavy Magnum
0.975 diameter for the Varmint
At the muzzle of each barrel is:
0.705 diameter for the Heavy Magnum
0.850 diameter for the Varmint
Considering the the main difference of the two barrels starts at the middle and then goes to the muzzle, I can only assume that this difference in thickness would only effect (aside from the weight of the barrel) the time it takes for the amount of heat to build up and the time it takes to cool down ... in my case, I hardly think there is ANY serious issue with that since I dont plan on shooting too many of those 7-dollar rounds too quickly, ya know
and so that leaves the diameter of the muzzle to consider ...... on Shaw's order form I will be choosing the option for a 5/8 x 24 thread being put on the end of the barrel. Although my dad could thread the barrel for me, we both agreed that I will just pay Shaw to do it since it's only an additional 30.00 for that option.
So when it comes to the differences in muzzle diameter between the Heavy Magnum and the Varmint , and then looking at the muzzle brake for the 416 Rem Mag barrel, what is your thoughts on how the 0.705 muzzle diameter of the Heavy Magnum barrel, and the 0.850 muzzle diameter of the Varmint barrel effects the type of muzzle brake that should be used