In my mind, if you are ever unsure of a caliber to go with for hunting, you can't go wrong with a 308 Win.
For long range shooting, it can have an effective range out to 1km, for hunting, you can load up 180 grain bullets that can have enough energy to knock down moose out to 300 to 400 yards. Availability of ammo and components is a no brainer and well priced.
To leave the 308 Win caliber is basically to improve on one aspect to the detriment of another. The 308 Win is not the best at everything, or really anything for that matter. Actually, I shouldn't say that, it is the best at being good at everything. There are a number of other calibers that shoot the same diameter projectile (30-06, 300 Win Mag, 300 WSM, 300 RUM, etc.), so the main differences you are looking at with the other .308" cartridges is going to be in powder loads, cost of ammo and availability of firearms for those calibers.
300 Win Mag is a great caliber, but the rifle is more expensive, brass is more expensive and you use more powder, but I can launch a 180 grain projectile about 400 to 500 fps faster in the 300 Win Mag than a 308. With this caliber, you sacrifice on cost, but you gain in both maximum effective range, size of game you can take, and a more extended range that you can take on bigger game. Your intermediate would be a 300 WSM, which is like a compromise between a 308 Win and 300 Win Mag.
If you want to reduce cost, and increase maximum effective range, then you would look at something like a 243 Win. This is a great cartridge for varmint and deer out to medium ranges. Because of the smaller caliber, recoil is light and bullets are cheap. This cartridge is basically a 308 Win adapted to a .243 bullet, so rather than using all that space for powder to push 150 to 200 grain bullets, you're using it to push 60 to 100 grain bullets up to 3500 fps, give or take depending on bullet size. This is about 20 to 30% faster than 223 Rem at similar weights.
308 Win will be similar to but more versatile than most 7mm cartridges, though there are some good bullets in this range that can reach out quite far. To really improve on velocity, energy and effective range over 308 Win, then you might start looking into 338 class cartridges, with the gold standard really being the 338 Lapua. In this cartridge, you can push a bullet that is about 30% heavier about 10% faster, imparting serious amounts of energy into your target and extending its maximum effective terminal range over the 308 Win, but costs will start spiking up quite a bit, and you will start venturing into the world of having "too much bullet" for some targets.
Have I sold you on the 308 Win yet? No? Well, how about this... 308 Win is a NATO standard cartridge (7.62 NATO), which means that if you have an interest in black rifles, you can get AR-10 variants and other 30 caliber black rifles in this cartridge as well. I personally went with 308 Win for all the reasons stated above, plus I have a Kel Tec RFB which is a 308 Win rifle. There are also a lot of other rifles that I have interest in, like the Desert Tactical SRS-A1, that can be converted between 308 Win and 338 Lapua. Because .308 Win (like .223 Rem) is a NATO standard cartridge, you will find that a wide selection of firearms are available for it.
If you intend on building out your gun collection in the future, and wish to avoid having many different calibers in your collection, 308 Win and 223 Rem are your top cartridges to consider.
For long range shooting, it can have an effective range out to 1km, for hunting, you can load up 180 grain bullets that can have enough energy to knock down moose out to 300 to 400 yards. Availability of ammo and components is a no brainer and well priced.
To leave the 308 Win caliber is basically to improve on one aspect to the detriment of another. The 308 Win is not the best at everything, or really anything for that matter. Actually, I shouldn't say that, it is the best at being good at everything. There are a number of other calibers that shoot the same diameter projectile (30-06, 300 Win Mag, 300 WSM, 300 RUM, etc.), so the main differences you are looking at with the other .308" cartridges is going to be in powder loads, cost of ammo and availability of firearms for those calibers.
300 Win Mag is a great caliber, but the rifle is more expensive, brass is more expensive and you use more powder, but I can launch a 180 grain projectile about 400 to 500 fps faster in the 300 Win Mag than a 308. With this caliber, you sacrifice on cost, but you gain in both maximum effective range, size of game you can take, and a more extended range that you can take on bigger game. Your intermediate would be a 300 WSM, which is like a compromise between a 308 Win and 300 Win Mag.
If you want to reduce cost, and increase maximum effective range, then you would look at something like a 243 Win. This is a great cartridge for varmint and deer out to medium ranges. Because of the smaller caliber, recoil is light and bullets are cheap. This cartridge is basically a 308 Win adapted to a .243 bullet, so rather than using all that space for powder to push 150 to 200 grain bullets, you're using it to push 60 to 100 grain bullets up to 3500 fps, give or take depending on bullet size. This is about 20 to 30% faster than 223 Rem at similar weights.
308 Win will be similar to but more versatile than most 7mm cartridges, though there are some good bullets in this range that can reach out quite far. To really improve on velocity, energy and effective range over 308 Win, then you might start looking into 338 class cartridges, with the gold standard really being the 338 Lapua. In this cartridge, you can push a bullet that is about 30% heavier about 10% faster, imparting serious amounts of energy into your target and extending its maximum effective terminal range over the 308 Win, but costs will start spiking up quite a bit, and you will start venturing into the world of having "too much bullet" for some targets.
Have I sold you on the 308 Win yet? No? Well, how about this... 308 Win is a NATO standard cartridge (7.62 NATO), which means that if you have an interest in black rifles, you can get AR-10 variants and other 30 caliber black rifles in this cartridge as well. I personally went with 308 Win for all the reasons stated above, plus I have a Kel Tec RFB which is a 308 Win rifle. There are also a lot of other rifles that I have interest in, like the Desert Tactical SRS-A1, that can be converted between 308 Win and 338 Lapua. Because .308 Win (like .223 Rem) is a NATO standard cartridge, you will find that a wide selection of firearms are available for it.
If you intend on building out your gun collection in the future, and wish to avoid having many different calibers in your collection, 308 Win and 223 Rem are your top cartridges to consider.
