Sveral years ago I built a 6mm tcu for my wife. 20" barrel. It has taken several antelope and deer. Very accurate, and no recoil to bother you. I personaly have harvested several antelop with this rifle and cannot tell the difference in the wound channel from my 243. We are using a 80 gr remington sp bullet and BallC2 powder. I think the 6 X 45 would do just as well.
Thanks for the response. I have an extra single shot Savage model 12 and I'm thinking of a rebarrel in 6x47, 6mm or 6.5mm TCU since I have dies for the TCU's. I like the TCU's in the two XP-100's that I had rebarreled. I shoot 100's in the 6mm and 120's in the 6.5mm. I use Blc2 or H335 for my loads. 80's shoot good in the 6mm but can leave a 200 meter ram standing if you hit it low. JM
"I guess It would have the case capacity of a 6br."
Actually, the 6mmBR (Norma) has a case capacity of 38.0 gr. of H2O to the top of the neck while the 6mm T/CU has 32.2 gr. using Lapua cases. I've used several Mini-Mausers with 22" barrels built for depredations hunting chambered for the 6x45 which has a 23 degree shoulder similar to the 6mm-223. Your 6mm T/CU with the 40 degree shoulder will work great in the single shot Savage. I also worked with a couple of Sako A1's using the 6x47 cartridge which has just a pinch more powder capacity since it's based on the .222 Remington Mag. case.
One neat variation would be to get a CZ-527 Carbine and have the .223 Rem. barrel re-bored up to 6mm and then just run the finish reamer in for headspace. You might have to do a setback but not if your gunsmith was super careful. With the 18-1/2" barrel, this would be one of the handiest carbines I've seen and it is drop magazine fed. The other alternative would be to get this same rifle and replace the 7.62 x 39 barrel with a 6mm and use a 6PPC chamber.
The loads I worked out use the 85 gr. Nosler Partition powered by the good old fashion IMR-3031 running about 2950 FPS on a full case. The 95 gr. and 100 gr. NPT work just as good but at a slightly reduced velocity. You could go to a heavier bullet made by Wildcat Bullets up in Canada but the loss of case capacity sort of defeats this.
This is an easy case to form and as mentioned, very mild in recoil and noise.
The 6mmBR is rising rapidly to the top of the accuracy classes for longer range target shooting. It now holds a few records and will yield more velocity and therefore energy from shear case capacity.