Have any of yall ever wondered what made the military choose the .308 win over the .270 win. I recently started wondering that when I was messing around on the ballistic calculator on my phone I began comparing the ballistics of the .308 and the .270 to see what the how different conditionds effect the flight paths of the bullets. At first I was just using the best flying cartridges from both the .270 and .308,but then I decided to try the exact same cartridges. What I found was that the .270 had better ballistics as far as bullet drop and wind drift when put under the same conditions as the .308. Have any of yall wondered this or even know why the military doesn't use .270 over the .308?
.270 and .308 are significantly worse than other chamberings of the time. The average 130 gr. .270 round and 150 gr. .308 round are about as slick as a brick flying through the air, .30-06 was no better. The 8mm Mauser round was far superior, and the 6.5x55 Swede is probably the best military round ever to be fielded.
.270 and .308 are only around because of politics and marketing ... as a caliber they both are crap.
270 has taken quite a few animals in my experience, and is a very capable hunting round... it isn't worth a darn for long range precision shooting, but as an inside 400 yd hunting round it does have alot of merit for terminal ballistics.
i agree with you on the 6.5x55 cartridge, the high SD of the bullets coupled with high BC's make it a very effective round for both long range precision and taking big game (moose)
i am thinking long and hard on the next 6.5 gun i build, either 6.5-06 or a 6.5wsm. i would try and revive the 264 win mag, but i don't want to go the belted route...
Let's face it ... just about anything with good shot placement is going to drop game in this area of the world, and humans aren't exactly hardy animals.
because the military switched to the 308 after determining the .30-06 was too long, both as a cartridge and a rifle
you can carry more .308 rounds than .30-06. the bullet is the same, but the brass and powder is less weight with the 308. the bolt rifles will be somewhat lighter as well, due to less metal in the bolt and action
the 270 is a necked down .30-06 thats why it shoots flatter, there is more powder available. more powder capacity means more velocity, more velocity means it carries out to range with less drop...
with the chambering of machine guns to shoot .308 the cyclic rate is a LOT faster because the bolt doesn't have to travel as far back as it would to chamber the .30-06 round...
so more ammo capacity, faster shooting, and lighter equipment is why they use the .308 vs. the .270
Those are also the same reasons that the military went with the 5.56 over the .308 when it adopted the AR.
The .30-06 was designed for the powders of the time. It could be shortened to the .308 without losing much velocity. The shorter cartridge was cheaper, lighter, and took a shorter distance for the bolt to move - a very good thing for machine gun designs.
I hate to disagree with Senor El Guapo, but neither the .270 nor the .308 are crap. Both are pretty decent rounds, as is the parent round, the .30-06. They get the job done without the excessive recoil of magnum rounds.
If you had said that about the .223/5.56 cartridge, I might agree. The only plus it has is that it's lightweight so it's easy for a soldier to carry a lot of rounds.