You seem to want to stay with Diabolo pellets. Most accurate and Diabolo mean dead calm or reading the wind. A RAW .30 is amazing and the Russian Jager .30 is quite unique. There's the original version w/ a 17 some inch barrel, and a new 20 some inch barrel. Neither Jager barrels are choked. Most reports I've read and tuners, owners I've talked to say the lands mic at .306" so cast .308's swaged down 2 thousandths (or buy a mold) are getting amazing accuracy out to 200 yards. I just talked to another owner and he said he's got a 17 some inch barrel model spitting JSB 44 grain Diabolos and hitting on target at 150 yards. I know he had to turn the power down as this Russian gun was made to shoot cast heavy slugs hard. From what you wrote, I'd say spend the 2K and get a RAW .30 Martin has different barrels and if you tell him exactly what pellet, distance, etc. you want it to shoot best at, he'll tell you what barrel you need and set it up for you.
I also know testing is being done mixing and matching new barrels on RAW rifles. If they shine above factory ones, it's an aftermarket option you'd have to do yourself or pay a machinist tuner. I myself am watching and waiting. There's leaps and bounds being made. The Crown, I believe, is a good option if you don't wish to have a dedicated caliber, are good at setting combos up, have a chronograph, etc. I also hear many FX's are a very common rifle to be in a tuners shop. They're good. They aren't a RAW, which is heavy and built to last. There's 2 things a FX may have a RAW beat on. That may be their valve is more efficient and their new STX barrels MAY prove better by not leaving any marks on pellets. I kind of wish Mike of Thomas Air rifles would make a .25 or .30 and I still say double 500cc 4500psi tanks would be the way to go for any big bore, especially a lightweight .257 as my farthest distance would be 200 yards for Groundhogs. I'm not trying to set any records. Good luck.
