Croldfort,
Ackley claimed the only cartrides that satisfied him in his Imp line of cartridges were the 250 Savage, 257 Roberts and 7x57, these 3 gained about 300 FPS and that is a substantial gain.
As to the 338-06, and from a practical hunting standpoint there is little, if any advantage to improving it..But, I would suggest there might be some advantage to case life, another 100 ot 150 FPS in velocity, better head spaceing and less case trimming as the IMP cases are alleged to streatch less and I think I agree on this, and one probably has more room for his bullets and if you have a long chamber and magazine then you can add even more velocity, all the same ole stuff, and it has some merit, but at the price of time and effort.
I wouldn't expect any better killing power as there is plenty to spare in both..
In my opinnion, and I shot the 338-06 in both std. and IMP. early on, the best way to improve the 338-06 is to rechamber it to the 338 Win.
The 338 Win. walks off and leaves the 338-06, it does not have any more felt recoil that I can tell, it works out of the same size action, if you want 338-06 performance then use less powder in your 338 Win. It really improves on the 338-06 IMO and in the same rifle..At least that has been my experience and Elmer Keith agreed with that.
I can push a 210 Nosler at 3005 FPS with little pressure, and a 300 gr. woodliegh at 2500 FPS, that is way beyond a properly loaded 338-06.
I have no problem with the so called dreaded "belt" for you belt bashers, it's been working on the 375 H&H, 300 WBY, 416 Rem, 7 MM Magnums for 200 years, and with honors.
If I wanted a non belted 338 then I would go with the 9.3x62 as the best bet..Whoops I have one of those also.
Not bashing the 338-06 or the 35 Whelan (same catagory as the 338-06), they are both definately good cartridges, just that IMO there are a couple of better options out there for your consideration.
