.277 Wolverine
 

Well figured I would share the load success. I loaded up 95 gr TTSx and 90gr Nosler Bonded Performance in the Wolverine trying to find the right load for next year. With the 10-15 mph winds I don't think this rifle did half bad. All were loaded with A-1680 in 23.1, 23.3, and 23.5 grains of powder. Both types of bullets were loaded to .050 and .040 off the lands of the barrel. Anyways here are some of the pictures and the velocity reports coming out of a 20" barrel.
Pictures of the groups the three (the bottom right one was a flyer from another load) shot group was the TTSX and the five shot group was the Nosler's (pulled the last one). Testing was at 100 yards.

Looks like a .223 necked up?

Yeah same concept as a 300 blackout just with a .277/6.8 bullet. It is fun shooting rifle, there are reports of guys getting loads up to 2800 fps with the 90 gr bullets and 2700 fps with the 100gr but I haven't pushed it yet.

I have a 10 inch 7mm TCU barrel for my Contender. That is basically a .223 necked up to .284. Sweet shooting rig. Mine id deadly with 120 gr Nosler BTs.

Is the 7mm TCU OAL to long to fit in a standard AR mag?

Probably. All I do is neck up from .223 to .284 so the brass will fit and all you would have to do is make sure the bullets are seated deep enough. A 120 gr 7mm bullet really isn't very long so you shouldn't have any issues. The good thing about using .284 vice .277 is a lot better selection of bullets but other than that there probably isn't any major difference.

The 7mm TCU has proven to me to be very effective on southern whitetails but I admit I haven't tried it on anything bigger. The 120 gr Nosler BT is inherently accurate and tips deer over very nicely. On days when I don't feel like lugging a long gun around I grab the Contender and know that if I miss a deer at 100 yds it will be my fault and not the fault of the rig.