RE: modifying mod 7600
Browning once made a pump called the BPR. They were discontinued a couple of years ago. They were available in 300 Win. Mag I know for sure. I would think they were available in 338 also as the BAR is. If not you could have a 300 rebarreled or rebored to 338. I think this is your only viable option unless you settle on a 35 Whelen in the 7600. The only other thing would be to rebarrel a 7600 with a 338-06 barrel and shoot 210 gr. Nosler Partitions out of it. I think I would settle on the BPR.