If you want to re-barrel both of them to get a larger bore than 300 you could do a 325 WSM. I rally like mine, I can shoot the 220s, but I choose to shoot the 200gr AccuBonds and Partitions our of mine. It's a real shooter and the COAL limits of the A-Bolt don't come into play too much. In my 7mm WSM however, I feel like I'm stuffing the bullet so far in the case with the 162gr ELD-X. Going to something like a 6.5 SAUM or the like might be beneficial. Personally, I'm not changing the cartridges in my A-Bolts, since I have the 243 WSSM, 7mm WSM, and 325 WSM (6,7, and 8mm that's just fun in matching rifles). I have the Timney springs in all of mine and the triggers feel great. I have talked to Carbon6 and they did say that they could make me pre-fits for the rifles. If you find a good carbon stock for the A-Bolt I'd be interested in knowing where, maybe Stocky's?