What does 100fps get you? A negligible amount of energy on target and scopes have turrets so you can dial up a couple mils so I'm not seeing the advantage....
If you need more speed I would step up to larger case then like a 26 nosler rather than cutting a m240b throat to play pressure games but that's just me
For a target rifle shooting 1 MOA steel targets, i would agree that 100 fps more muzzle velocity buys you almost nothing. Example, for a 140 ELDM target bullet, that is one click less wind drift at 1,000 yards.
The 6.5 PRC with all that extra case capacity makes for a viable long/er range hunting cartridge - even with a shorter barrel. As long as the bullet expands adequately to kill the game animal, all is well. [The 6.5 Creedmoor with the right bullet is an adequate hunting cartridge for short to medium range (<300 yards), but it is not really ‘long range capable.] Your 6.5 PRC is achieving somewhat lower speed than a 26” 6.5CM due to the shorter 22” barrel, but it will be a fun rifle to hunt with.
At 600 yards, shooting a 143 ELDX hunting bullet at 2,500 fps, another 100 fps only buys you one click less wind drift. That is roundoff error.
However: Bullet expansion limitations are another matter: Hornady claims that their ELDX bullets expand down to 1,600 fps:
“The new Hornady ELD-X™ hunting bullets are designed to deliver the highest BC possible for the specific bullet caliber and weight. They also provide match level accuracy at long range and effective terminal performance from maximum safe initial velocities down to ~1600 fps." That is an impressively low number, but do understand that the bullet reaches minimum expansion velocity at that speed, and below that it mostly pencils through the animal, and it runs off to die a slow and painful death. I prefer to set a much more conservative lower limit for myself of 2,200 fps, to ensure full expansion of the bullet, and significant hydrostatic shock, so there is no need to track the animal through the timber. It also helps if shot placement is 4” off due to a bad wind call.
If you accept my rather conservative velocity limit, then assuming 2,500 fps for a 143 ELDX (improving to 2,600 fps) moves your hunting range limit from 280 yards to 370 yards. That can be significant in some parts of the western states where you need to shoot across ravines. For woodland hunting, or hunting from a blind, it is a non-issue. [Pick your own lower limit depending on bullet and game species, and run the calcs in a ballistics calculator.]
In my experience, the choice of powder can gain you 150 fps, ordering the barrel with an extra 2” can gain you 50 fps. Use of an HBN coating in a 6.5 CM gained me close to 80 fps, for an optimized load that was a good 100 fps away from bright ejector marks, so i could have had more. [Did that mostly for brass life.] But the load manuals are not much use to you if you go this route. Premium brass handles pressure better, and ejector marks show up a little later. A combo of “all of the above” will likely get you to over 2,600 fps.
A Melonited barrel is smoother and can allegedly gain you significant speed as well. We have a Blaser R93 hunting rifle on the ranch in Namibia with a set or factory Melonited barrels that easily exceeds max book speed, with very safe hand loads. Not particularly expensive either.
A good high BC copper hunting bullet (3x more expensive) can gain you a very useful range extension too, but not all rifles shoot them well. Also check the minimum twist rate spec.
Have heard about the Defensive Edge +P chamber modification, and it seems many people who have tried it got good results, but not all. Depends if you have spare case capacity left to stoke the load. [HBN has a similar issue.] I have not tried them yet, but might do so later this year for a 300 WSM that needs to shoot long heavy copper bore rider bullets at 2,500 yards.
Practically speaking: You probably will not need to hunt beyond 400 yards anyway. Be aware of your own skill limitations (like wind reading), the expansion limit of the bullet, and the accuracy of the rifle, then simply stay within that envelop, and go out and enjoy your new riffle!
