.308 short mag?

DarkSith

Member
EE Expired
Rating - 0%
0   0   0
is there such a thing? I was going through some old brass I inherited and I found some 308 rounds along with a 30-30 casing. They are almost the same size, and this confused me as I thought a .308 was a much larger shell due to its ability to get down range, while I understood that a 30-30 was good up to 200y or so. Are there multiple sizes of .308 rounds?
 
there is no 308 short mag. the 308 does have more powder capacity but it is not a large case. i use 31.5 grains of imr 4064 in my 30-30 and 42 grains of imr4895 in my 308. 308 also uses pointed bullets which is a huge advantage over the 30-30's round nose bullets. the .308 is not a flat shooter but it has a lot more punch and much better ballistics than a 30-30.
 
Yes....and ...no!

A .300 Win Short Mag and .300 Rem Short Action Ultra Mag, .300 Ruger Compact Magnums (and the short Lazzeroni offering, what ever its called) are .308" calibre magnums, that are shorter than the common magnums that came before them.

The .308 Winchester is a different cartridge altogether. It too is considered 'short' but is not nearly as wide in the case as the much newer 'short magnums'. The .30-30 is also a .308" calibre cartridge but has less case capacity than the .308 Winchester.

The other big factor is the chamber pressure that these cartrides are designed for. I don't have the numbers with me but the .308 Winchester, like most of the common non-magnum calibers operates at a maximum of about 60 000 - 62 000 psi chamber pressure, the short magnums at a max of 65 000 and the old .30-30 much lower than that, little over 40 000?)

.308 refers to the bore diameter between the grooves of the rifling, .300 between the rifling lands.
Cartridge nomenclature can be confusing but almost all the '.30' calibres use a .308 bullet (except the .303 Brit, 7.7 Jap, 7.62x39 and 7.62x54R -well some rifles chambered for the latter 2 do in fact use a .308, not the .311"/7.7mm!).

This means the .30-30, .308, .30-06, .300Win, .300 WSM, .300H&H, .300 SAUM, .300Ultra, .300 Weatherby, .300 Blaser, .30R Blaser etc etc etc all use the same diameter bullet - .308". Each one has a different case capacity and there are different maximum operating pressure specifications that rifle and ammo makers adhere to. Most cartridges fall into only a few different max pressure spec bands. Therefor a .308 Win way outruns .30-30 because 1) it holds more powder and 2) it operates at a much higher chamber pressure, therefore pushing the bullet with more force.

Thats the summary description :)
 
thanks, that is great info for a noob like me. Another question though, why is the .308 winchester considered to be a farther shooting rifle than the 30-06 then if the 06 can hold so much more powder?
 
Really when you look at it a 30-06 is just a long 308 case or vice versa. More powder with same boolit-well it goes farther and faster. My '06 is loaded pretty hot and is a tack driver way out past 200m with 180gr. My 308 is not quite there yet but I am working on it. If you think about the physics of it the 308 will never outmatch the 30-06 but it will come close. Both real good cals. There is lots of 308 case stuff-look at 243, 250 and 300 Savage etc. Pretty common design. Its a really big family. Open your reloading manual if you have one and start checking dimensions. Verrrryyyy Interesting. Me I think they are all wildcatted from the original 30-06 anyways. Would explain a lot.
 
Back
Top Bottom