In order to participate in the GunBroker Member forums, you must be logged in with your GunBroker.com account. Click the sign-in button at the top right of the forums page to get connected.
Ballistics?
imacbo
Member Posts: 310 ✭✭✭
Out of the older military rounds which has the better over-all for ballistics? a) 7.62x54R b) .303 c) 30.06 d) .308 When I said better I mean which drops less, has more knock down power, ect. ect. I know that it will depend on the weight of the bullet so lets say a 180gr. and lets say at 1000yrds.
Jeremy Bowles
Jeremy Bowles
Comments
why chase the game when the bullet can get em from here?....
Got Balistics?
Of those choices the 30-06 has the best bullet selection (.308 diameter) and case capacity. The 308Win is at the tail end of the pack in the capacity department, but gains points for bullet selection (also .308 diameter).
The 303Brit and 7.62x54R fall into the middle due to limited bullet selection (.312 diameter*) but gain points by haveing case capacities that are only slightly less than the 30-06.
*I know that the 7.62x54R is supposed to use .308 bullets (but every one I've slugged has run oversize, got one right now that runs .316) they seem to prefer the larger diameter bullets if the chamber neck will accept them without pinching.
Some guys like a mag full of lead, I still prefer one round to the head.
This question can be answered in several different ways based on the cartridges that you ask about and the parameters.
The easy answer is the 30-06 Springfield will be the correct choice based on highest velocity, retained energy, and accuracy when paired with a bullet that is both aerodynamic and constructed correctly. As an example, you can load a 30-06 with 180gr. HDY AMAX with a BC of .580 at a velocity of nearly 2900 fps. The total drop at 1000 yards will be approximately 304" with a 200 yard zero. But merely switch the bullet to a 180 gr. HDY RN with a BC of .241 and the total drop at 1000 yards will be approximately 669" with the same zero, or more than double the AMAX bullet of the same weight. So aerodynamic efficiency can be a large determining factor.
Another factor that needs to be taken into consideration is case or cartridge pressure as established by SAAMI and case capacity.
30-06 = 60,000 PSI / 68.0 gr.
.308 = 61,190 PSI / 56.0 gr.
.303 = 45,000 PSI / 56.0 gr.
7.62x54R = 45,000 PSI / 64.0 gr.
These figures make it fairly obvious in favor of the '06 but the comparison that needs to be made is between the .303 Brit. and the .308 Win. Both have the same case capacity but the operating pressure is 16,0190 PSI greater for the .308 Win. Maybe that doesn't seem significant but it is a roughly 1/3 increase in operating pressure which can be an equivalent to 150 to 200 FPS. And maybe that doesn't seem real significant either when short ranges are considered. But, discuss 1000 yard shooting and you have a sizable, significant difference at the 1000 yard line. Combine this with the aerodynamic features of a particular bullet and suddenly things start to shift to favor the .308 Win. Case capacity is not the deciding factor in power or velocity let alone accuracy.
Lastly, take a look at the shooting sports that employ any of these cartridges. Palma, both U.S. and International, use the .308 Win. cartridge for competition, exclusively for International and voluntarily for U.S. The U.S. allows any cartridge while the International specifies the .308 Win. and the 155 gr. Sierra Palma bullet loaded to a specific length and velocity. Basic reasons: widely available due to Nato's influence and very accurate.
Regards.
If you ain't got a sense of humor you got no business bein here!