Striker Calibers

[bootsmcguire]

I decided to run some stuff through my basic ballistic calculator program just to see what would present itself.

A 7mm TCU loaded with a 120gr Sierra Spitzer at 2000FPS (1,066 ft/lb at muzzle) has a trajectory like this:

50yd = +.44--- 947 ft/lb
75yd = +.54
100yd = 0.0--- 841 ft/lb
125yd = -1.24
150yd = -3.17--- 745 ft/lb
175yd = -5.90
200yd = -9.38--- 660 ft/lb

A 6x45 shooting a 100gr Sierra Spitzer at 2400FPS (1279 ft/lb at muzzle) has a trajectory like this:

50yd = +.080--- 1160 ft/lb
75yd = +.250
100yd = 0.0--- 1050 ft/lb
125yd = -.700
150yd = -1.880--- 949 ft/lb
175yd = -3.540
200yd = -5.720--- 857 ft/lb

I chose those two bullets as I have used both for deer at near and far ranges with good success. I pulled the velocities from my loading manual and stayed a tad conservative due to your pistol length barrels. I even ran a 150 gr 7mm bullet at 1800fps and the 6x45 data above beat it in trajectory and energy.

Based off of this data, the case restrictions you seek, and the ranges you wish to kill at, I would lean towards the 6x45.
Hope some of that helps in your decisions.