I made myself a "AR10" in the 308 and added an additional upper in 358. Using 180- 220 grain bullets my 358 outshoots my 308.
I have yet to kill anything with it, but I have made a number of 358s in bolt actions for customers over the last 40 years and all of them loved the guns and the results on game. One man I made a 358 for over 30 years ago lives in Jackson Wyoming and he uses it for all hunting including antelope. He is in love with the gun and the cartridge.
I would give a tip: Use a 1-12 twist instead of a 1-14. Mine had a 1-14 and with the 225 grain boat tailed tipped bullets it's not doing the job for me. I use a 180 of 220 grain flat base flat points or round noses and the same barrel is shooting 3/4" to 7/8". With the 225 gr AccuBonds I was getting about 8' to 9" and many holes were not round, showing me a yaw in flight. I have no other explanation but twist rate.
The boat tail and the plastic tips make for very long bullets for the specified weight and it looks as if 1-14 is simply not doing the job. Since I made that upper I have stopped using any 1-14 twist barrels on any other 358s (and 35 Whelens too) and using 1-12 has done all I want in every gun since, with no down side.
So from what I have seen, all you can do with the 1-14 you can do as well with a 1-12, ----but the reverse is not true.
What barrel length did you go with for the .358 upper and are you happy with the performance of it?
