Thanx thetooner, that makes sense. I currently own and shoot a mossberg 22 and an sks. Ill look at the 308 for sure, mind you i like your thinking. Start with the 223 then get the 308
Since you already own a 22, then I think a 223 would make a good logical progression. Cheaper 223/5.56 will run about $8-10 per 20, so you can certainly get a lot of shooting and practice in, and when it comes to hunting or target shooting there is an endless amount of great factory stuff. I think a nice bolt 223 would work well for you as well, because you currently own two autoloaders (not sure how the Mossberg is for accuracy, but the SKS has it's accuracy limitations), it would be a good way of really learning shooting techniques and fundamentals (a good accurate rifle/good ammo will let you know when you are doing your part and when you're not). You could also use it for varmint hunting. I would probably hold off on reloading at this point (but I do highly recommend, as it's very addictive and rewarding).
As for the Mossberg, I haven't seen a whole lot of reviews, but the ones I have seen have been pretty positive. I have to admit, I like the AR mag compatibility. Most of the reviews have shown them to be 1 MOA rifles, so they are certainly accurate enough, and you can certainly take them out to several hundred yards (mind you many people shoot 223 much farther than that). I'm partial to Savages myself, but I also like tinkering/building. They certainly make some very cool looking factory rifles to (I've owned a good number of them, they all have proved themselves very accurate). A Rem 700 would also be a great rifle to start with (there are many others though).
You will want something more than a 223 for big game, and like some other members have said, this isn't the only gun you will buy. You can always sell guns as well, it's not like it's a big deal if you change your mind down the road. The more you shoot and research, the better you will learn what works for you, and what you will need for future shooting/hunting.