since i have a .308-and hunt with it, i would like to offer some observations and advice.
i believe that the .308 is the most versatile rifle there is; followed very closely by the .30-06. mine is a herter's mj9 (yugoslavian mauser manufactured by zastava in the mid-sixties) topped with a tasco (phillipines, NOT china) 3-9x44mm scope. it is a good all-around combo for anything i am likely to hunt in montana, from proghorn antelope , to mule deer , to whitetail deer to elk . the first thing i will say is practice practice practice!
regarding "point blank range," i would suggest a 250-yard zero, which will put you in an 8-inch kill zone out to 300 yards. a 200-yard zero is fine, but a 250-yard zero will compensate for any error in estimating range. i STRONGLY recommend going to www.huntingnut.com and downloading the free POINT BLANK program. play around with it a little and learn a few things about ballisitics. not only is it fun, but it will prepare you for the field, helping you to kow exactly what your rifle can do. before i got this program, i had visions of popping mulies at 600 yards with my .308.....this program woke me up, and made me a little more aware of what a rifle can do, and do WELL, as long as you know its limits.
with a .308, i would say that 165 grain is optimum up to mule deer. 150's are more than adequate, but it doesn't hurt to adjust the percentages in your favor.
for elk and larger, you definitely want to at least look into using 180-grain. 165's would probably be fine for a broadside kill-shot, but the 180's would penetrate much better and pack a little more punch, which is a plus when going after big animals which can run fast and disappear into thin air after they are wounded, but not killed outright.
regarding ammunition, "rolling your own" is probably the best option. you can tailor the bullet, load and other factors to your rifle, and achieve some very surprising accuracy. for 20$, you can buy a lee loader in .308 and see for yourself. along with the lee loader, i would recommend forking out an extra 13$ for the two-piece case trimmer and lock stud combination made by lee. this is really all you need to start loading very consistant ammunition that will be much better than factory. if that milsurplus ammo you bought for practice has a standard "boxer" primer, SAVE THAT BRASS and reload! you will save money and have a great time, and have great ammunition. if it is berdan-primed, then take it to the recycler and invest a little $dinero$ in some virgin winchester, federal or remington brass.
if you choose not to reload, any factory ammunition will be adequate, especially if you have a newer, quality rifle. remington , winchester and federal are proven names with good stuff. the pointed soft points (spitzers) are the best all-around choice for any game.
bullet selection. the top two that i would suggest for game up to and including mule deer are hornady interlocks and sierra gamekings , both in the boat-tail variety. this is not the most popular choice, but i believe that the boat tail gives you a distinct advantage at ranges past 200 yards. even if you don't plan to shoot past 200 yards, it is not always easy to judge distances, and the boat tail might make up for the error. one guy, whom i trust, said that he had some dramatic failures with the interlock system, but i believe that these were due to the extreme velocities that he was pushing in his rifle, and the older-style interlocks were simply not designed for it. premium bullets ( nosler partitions , trophy bonded bear claws , barnes x bullets )are a good idea on black bear as well as elk-sized game and larger, but not always necessary. once again, it is a good idea to adjust the percentages in your favor, and a premium bullet will do this for large or dangerous game.
ballistic tips by nosler and SST bullets by hornady are great for antelope and deer, but i personally do not trust them on elk-and larger-sized game. this does not mean that they don't work, it simply means that i don't know anything about their performance on large game. one thing is for sure, those b-tips with boattails will fly as fast and far and flat as the .308 will push them. for mule deer, this could give you the edge. for any b-tip style bullet i would suggest at least 165-grain and NOT 150's. a 150-grain b-tip MIGHT work fine, but under some conditions i believe that they are closer to varmint bullets, and when making meat it is best not to take the chance.
in case yuo are wondering about one bullet that would serve as an all-around bullet to cover any situation, there is none, but the closest thing to it for the .308 would probably be the 165-grain partition. you can load the nosler partition, or winchester makes this in factory ammo in their " supreme " line.
any questions, just ask; lots of people here willing to help. most of them know more than me, but these have been my observations. the last thing i will say is PRACTICE, PRACTICE PRACTICE!!!