Originally Posted by
DavidD.
I appriciate everyone's input, and have thought about it. Personally, I am writing the 30/30 off, just because I relized most of the thick brush I hunt it, my shots are usually 50 yards or less. That's what my old 12 is for! I am now debating between the .270 and the .308. So, when looking at ballistics, cartridge prices, etc, what is the better rifle?
Now we're talking. Haha! Of these two, I gotta go with the .308win...
For cartridge prices, the .270win and .308win should be about the same. Both are incredibly common, even call them "standard" rounds. For the reloader, the .308win is a bit cheaper, since it actually uses slightly less powder than the .270win. You should have a good selection of factory ammo for both to choose from, all the way from low budget stuff up through premium stuff (granted there's a lot of surplus .308 fodder running around that would be cheaper than .270 ammo, but not many guys ever shoot that stuff, so it's not really relevant).
Ballistically, both will have Ballistic Coefficients in the .30 to .45 range, with the .270win running about 200-300fps faster than the .308win. At 1,000yrds, I calculate about 290" of drop for a .270win, while the .308win is dropping 345". Frankly, if you can dope for 290", you can dope for 345", but it DOES drop more. However, even at 1,000yrds, both will have 550-600ft.lbs. left hanging on, and both will be right at the top end of the transition velocity (1300fps-1000fps isn't a stable range, as bullets come OUT of supersonic speed). At 500yrds, the difference in drop is 46" for the .270, to 53" for the .308. Personally, yes, the .270 is a little flatter, but no, I honestly don't think it makes much difference.
I see is a wash. The heavier .308win bullet should buck the wind a little better because it has higher momentum (about 10% more momentum), but it's also about 10% slower, so the wind has longer to take effect, and it will drop farther in the same timeline. Whatever advantage the .270win has for flattness, it loses in windage, but whatever advantage the .308win has for wind bucking, it loses for the extra drop.
For stopping power, they both run about 2850ft.lbs. at the muzzle. The TKO factor is higher for the .308, 19.5, versus 16.0 for the .270win. The bigger diameter, heavier bullet, in this case, makes up a lot of stopping power, giving it about 22% more stopping power on paper. What does that mean? Not much really. The .270win is likely going to penetrate a little deeper, while the .308win will likely do a little more tissue damage and give better bleeding and better hydrostatic shock, but if you stick either one through a deer's heart, it aint going anywhere. The 22% is mostly just a feel good, and would only make a difference if you MISS the heart by a fraction, the bigger wound channel of the .308win might save you. The .270 is more likely to pass through, which can be a good thing, or a bad thing. Exit wounds mean two things, bleeding, and wasted energy. The .308win is "less likely" to exit than the .270, but it's still very likely to exit, and it'll leave a bigger exit wound than a .270, which means more bleeding, and less wasted energy.
Recoil wise, neither are hard hitters, and if you can tell the difference between the two without specifically shooting them side by side just to feel it, then you're far better "calibrated" to recoil than I am. In theory, for me, again, it's a wash. The .308win has a bigger bullet and more momentum, so it should have a higher magnitude recoil. HOWEVER, the .270win is a faster round, so it has a shorter impulse, so the recoil happens faster, more of a kick, than a shove, so it's recoil curve peak gets "squished" up higher than it necessarily should be. Again, my shoulder isn't nearly sensitive enough to tell the difference.
Other considerations:
The .308win is easier on barrels than the .270win. Both run about the same max SAAMI pressure of 62kpsi (52kcup), but the .270 is running faster, burning more powder, and in a smaller bore. That's not to say the .270win is "hard on barrels", but it IS just a bit harder on barrels than the .308win. For the average "box of rounds a year or less" hunter, this isn't an issue. For a guy that does a lot of prairie dog shooting or a lot of paper punching, it might become a consideration.
The 308 has more versatility. Regardless of actual hunting versatility for game species, some states have 30cal as the minimum bullet diameter for larger game species. If you'll only have ONE rifle, the .308win will let you do more than the .270. The .270win really only reaches up to about 150grns, while the .308win can press up as high as 200-220grns, giving it a substantial increase in stopping power. Frankly, I've used a 30-06 (almost identical performance to a .308win) in 150,165, and 180grn for everything between coyotes and prairie dogs clear up to black bear and elk, and haven't ever felt the need to shoot a 200 or 220grn bullet, but a 30cal 180grn IS a lot more bullet than .277" 140grn.
The .308win fits in a short action rifle. This has several effects. The rifle can be slightly shorter without sacrificing barrel length (not much), the rifle will be slightly lighter (not much), the short action will have a shorter, faster handling bolt throw (not much), but most importantly, the action will have a more stable lock up, making it more inherently accurate.
So those are all the reasons I'd choose a .308win over a .270win as my "only rifle". If you're only ever going to hunt whitetails, then either is a good choice, if you might go for something bigger but only want ONE rifle, then 30cal is the way to go.