Anyways, what is everyone using as training ammo that groups close to the TMK’s?
Uh..... I don't know about "everyone" but the training ammo I use is the exact same 77 grain "TMK" handload I shoot CMP "Modern Military" and "Service Rifle" matches with and started hunting with last November.
Here is my former .250=3000 load, shot out of my 20" barrel Ruger M77RL Ultralight:
M / 2620 / 1524
100 / 2332 / 1229
200 / 2100 / 980
300 / 1865 / 772
I used that load above to tag 21 mule deer, 3 pronghorn, 2 caribou, 1 bull elk, and God Himself only knows how many California Central Coast feral swine it stacked up. Pop and flop, every time, and I never had to pull the trigger once per animal.
My experience with the .250 Savage informed my decision to settle on 5.56 NATO as the cartridge I would rely on to see me through my twilight years to the end. I'm not really a "numbers guy" but the numbers suggest that a .250 Savage loaded to SAAMI spec pressure has a lot more in common with the .223 Remington than the .243 Winchester, while field results suggested that there are some cartridges that kill all out of proportion to their data in a ballistics chart.
Here's the terminal ballistics of my 5.56 NATO load from my 20" barrel AR-15. (Distance / Velocity / Energy)
M / 2852 / 1391
100 / 2634 / 1186
200 / 2426 / 1006
300 / 2227 / 848
This is a load that I've been using in CMP matches and in practicing for those matches, anyhow. Seeing the results people were getting on game with the same bullet prompted me to give it a try, as having ONE load to do everything I want to do with a centerfire rifle simplifies life that much more.
Last November, I shot two whitetails with the 77 gr. TMK load, which really weren't much of a test for it. Later in the season, I shot a mule deer through the heart with it at 268 yards. This load made a wound channel of obviously higher volume that my 100 grain Partition .250 Savage load did.
I shoot matches, shoot targets for practice, and hunt with the same rifle and now, I use the exact same load for all of it.