slugshooter Posted March 18, 2005 Report Share Posted March 18, 2005 I've been trying to decide what caliber rifle I want to buy and am pretty much set on a .308. I went on the Remington site earlier and was looking up ballistics between .270, .30-06, and .308. I knew the .30-06 was gonna be better than the other 2 as far as velocity and energy, but here is where I get confused. I based the test on using a Remington Express 150 grain pointed soft point bullet. The .270 had greater muzzle velocity and greater muzzle ft-lb energy, but, downrange the .308's velocity and ft-lb energy was greater than the .270. Now, I am no engineer or physicist and really know nothing of rifle ballsitics and things of that nature. But shouldn't the .270 carry greater downrange velocities and energy than a .308 even though the bullet is bigger but cartridge and therefore powder grain would be larger in the .270 ? Does that make any sense ? Quote Link to comment Share on other sites More sharing options...
AJ Posted March 18, 2005 Report Share Posted March 18, 2005 Re: AJ.....or anyone, please explain. If you compared the Remington Express ammo with Core Lokt bullets in all three, the difference is with the .270 Win's bullet. It's using a round nose bullet. The .30 caliber loads are using a pointed soft point Core Lokt and the .270 is using a soft point. The soft point has a lot lower ballistic coefficient so the downrange trajectory will have more of an arch than the pointed soft point. With equal designed bullets, they are all very close. The .308 is a very efficient cartridge and comes very close to the 30-06. Close enough that you can not see a difference under hunting conditions. Bullet performance will be so close to identical, its not worth mentioning. When comparing the .270 Win with the .308, you will see their velocities are very similar. This is due to the bore size. When equal weight but different caliber bullets are compared, the larger caliber will always be faster at the same pressure level. Of course they have to be in similar cartridges to keep the data valid. This can easily be seen when comparing equal weight bullets in the .270 Winchester vs .280 Remington vs .30-06. The same can be said for shorter cartriges like the .260 Rem vs the 7-08 Rem vs the .308 Win. The larger caliber will be faster since the bullet is shorter. This gives it a smaller bearing surface that is in contact with the barrel. Their trajectories will be similar though due to the longer and skinnyer bullets that have higher ballistic coefficients in the smaller calibers. Any of your choices will be fine deer rifles. To say that one is better than the other is just an opinion. They are all pretty much equal in performance. If you limit shots to 300 yards, you can not see a difference in the field. Quote Link to comment Share on other sites More sharing options...
JimT Posted March 18, 2005 Report Share Posted March 18, 2005 Re: AJ.....or anyone, please explain. What AJ said.... Quote Link to comment Share on other sites More sharing options...
slugshooter Posted March 18, 2005 Author Report Share Posted March 18, 2005 Re: AJ.....or anyone, please explain. Thanks for the explanation AJ, even if I didn't understand it all, but I got the main gist of it. Quote Link to comment Share on other sites More sharing options...
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