WAIT A MINUTE, MY BAD, I looked at the winchester book and the 55 grain is a lot faster than I thought. Sorry for posting bad information. But the question still is, will it penetrate enough and expand enough. (fragment) from what I've read here the answer is yes and I'm going to find out. Bult 4 mud, I'm sure it does kill them quick but I don't have a .45-70. Actually I take that back, I do. It's hanging over my fireplace though and it's from 1873. So I don't feel like using it much. It would be fun though. I know there are lots of calibers that work on deer. I've used several. But I'm still going to try the .223.
also, I didn't really mean you needed nato pressures to hunt with a .223 that's not really the case. I just think it would be more effective, obviously.