I don't know a web site that will help but from my experiance with three of the 4 this is what I have found.
243 win , 243Ai , 240Wby all are great rounds for deer and long range varmints I have had all three and a 6mm-06Ai , and I now only have 2 , 243Ai.s. The differance in recoil between the three is so slight that you probably won't notice the 240Wby is packing a bit more powder so the recoil is slightly higher and muzzle blast is a little more but not much.
Personaly my vote goes to the 243Ai because their is great brass out their from Lapua ,the case shape offers a little bit more powder and a good bit longer case life than the standard 243 and the pressure seems to go up slower in my guns with the Ai case.
The 240Wby can honestly run a 100gr bullet out of a 26" barrel at 3300fps with no problem or sign of pressure and decient accuracy , bet accuracy was at the 3200fps range , I have stoked it up to 3500 but accuracy went ot hell fast.
The best I could get out of a standard 243 before pressure got high enough to flatten primers was 3250+ and accuracy was at about 3000fps
My Long range 243Ai is built on a Rem 700 short action and was built to shoot the 105gr A-max ,it has a 1-8 twist Hart barrel at 28" , best accuracy is at a velocity of just over 3200fps.
My other 243Ai is built for shooting deer and it wears a 26" barrel and has a 1-10 Hart barrel , bets accuracy comes from a 95gr Nosler Ballistic tip at a velocity of 3200+fps. It also likes 75gr V-maxes at right around 3800fps.
The 243Ai will do just about everything the 240wby will with less fuss and cost..
