If/when Indiana implements these new rules, one of which increases the maximum cartridge length for deer-hunting rifles from 1.625" to 1.800", you can expect some of the following to occur:
1) The 460 S&W, chambered in a T/C Encore rifle, will be used by many of the "progressive" hunters in the Hoosier state. The 357 Herrett will become somewhat popular, as well.
2) Wildcats based on many cases, including the 444 Marlin, 460 S&W, 450 Bushmaster, and others (as originally designed, or shortened/necked down) will proliferate. A shortened 375JDJ, as fired from a 24" Encore, would easily be effective on deer out to 250 yards. I personally might explore the 338ME case, shortened .090" and opened to shoot .358" diameter bullets.
3) Those wishing to push the envelope will start with 300 and 325 WSM cases, shortening them to 1.800" and expanding the case mouths to .358". These will give velocities exceeding the 358 Winchester and approaching 35 Whelen numbers.
In this extreme example, you now have a medium to long-range cartridge for deer-hunting. This is in contrast to the logic used by the Indiana DNR to support their "PCR" (pistol-chambered rifle) regulations. That their logic is flawed is clear to most experienced hunters and hopefully these regulations will be done away with entirely, instead of just increasing the length a ridiculous .175"!
Ironically, most deer will be harvested well within the lethal range of a 44 magnum or 357 Maximum. For those hunters who are used to, or at the very least appreciate, high-velocity, long-range cartridges, we will continue working within these absurd regulations to find the best possible performance for our deer-hunting rifles. At least these small, if dubious, changes allow young shooters to carry rifles while deer-hunting in the Hoosier state, and not endure the horrendous recoil of a 12 gauge slug-gun, or maintenance hassles of a muzzle-loader. If nothing else, maybe these changes will help ensure the hunting heritage for all of us hunting the cut corn and bean fields of Indiana.