Rifle cartridge question

[TheEqualizer]

Why do some cartridges have a two part numbering system, eg. ,30-06, .38-40, .30-30 Winchester, etc?

Thanks,

- andy

[gunderwood]

The short answer is because that's what they wanted to call it.

There is some historical precedent from the black powder days. E.g. .45-70 was .45 caliber and 70gr of black powder. There also was a .45-90 and .45-120, but with modern powders the .45-70 has plenty of capacity which IMHO is why it is the most popular of the breed.

30-06 was .30 caliber and adopted in 1906. On and on. Why do we call some engines by their liter capacity and other by cubic inches...because we can.

[Palladin]

+1 for on and on!

It's really interesting how the different families of cartridges evolved...

A 30-06 necked down to .25 becomes a 25-06. Neck a .308 down to 7mm, and get a 7mm-08, a little smaller and it's just a .243.

It's also cool how different cartridges perform so much better than others. For instance the little 25-20, necked down from the 32-20 pistol cartridge, can't hold a candle to the ballistics of the .22 Hornet, though looking at them side by side one might think the 25-20 packed more wallop... and on and on.

Get you a couple of reloading manuals, they look great in the basement and on the coffee table

[TheEqualizer]

I was thinking of getting a reloading manual. I plan to get into reloading some day but I am fascinated by the ballistics aspect and trying to get a deeper understanding of loads.

If you had to get one manual, which would it be?

Thanks.

[gregj]

You cant get just one manual, not if you plan on reloading. But the best one for starting out is the ABC's of Reloading.

[gunderwood]

You cant get just one manual, not if you plan on reloading.

+1

At least have a manual for the bullet brands you shoot (if available). Most of the name brand books do a pretty good job of explaining things.

[CowboyT]

Nope, one manual isn't good enough. Get more than one. With that, I'd say Lyman's 49th Edition is a pretty good one to have. I use it and Lee's "Modern Reloading", and both of these manuals are again checked against the data from the powder manufacturers' Web sites.