Originally Posted by Mule Deer
That is a classic example of the oxymoron "false logic."

Hornady Light Magnums (and any other U.S. commercial ammo made by a member of SAAMI) still has to conform to SAAMI maximum pressures. SAAMI maximum pressures for the 7x57 are lower than for the .280, even in "Light Magnum" ammo. I don't have the numbers at hand, but believe the 7x57 maximum is around 50,000 psi, and the .280 maximum 60,000.

In fact, handloaders can safely exceed the muzzle velocity of Hornady Light Magnum 7x57 ammo with "modern" pressures of 60,000 psi or so, even in a 22" barrel. Look it up in Nosler's manual. The top muzzle velocity listed for 140-grain bullets in the 7x57 is 2892 fps. With the 139 Hornady (which has a shorter bearing surface than any 140-grain Nosler 7mm bullet) you can safely go up to 2950 or so.

I have owned a pile of 7x57's and .280's, and tested them in pressure lads. The difference is about what's indicated with the 1/4 formula, 5%. This is admittedly hard to pin down from most manual and factory data, because of the pressure differences between the rounds. Or even barrel length differences. Nosler's manual would be much more useful in this comparison (since they load both rounds to about the same pressure) except for the fact that they tested the 7x57 in a 22" barrel and the .280 in a 26" barrel.

The 5% difference does come out to around 150 fps for most bullet weights. This amounts to about what bullets from the .280 lose 50 yards from the muzzle. So in theory the .280 has about a 50-yard advantage over the 7x57.

In something like a quarter of a century of handloading and hunting with both rounds, however, I can generally say that the 7x57's bullets will get to whatever animal is being aimed at, and kill. As will the .280's.

Naturally, this is only if the hunter in question is familiar with the rifle in hand, an ideal I know we all strive for.



No where did I imply that referring to Hornady's light magnums was an arbiter of handloading potential. In fact I quite specifically stated that is was merely a decent comparison of commercial loads and really proved nothing. As they utilize the same bullet and maximum safe pressures under SAAMI, it is better than trying to compare an arbitrary Remington load to a Winchester load or even two Remington loads which are often all over the map as far as pressure.

Not everyone handloads, so this would be a fair comparison for someone forced to buy commercial cartridges.

I understand that you can safely exceed SAAMI for the 7x57 through handloading, of course you can safely exceed 60k psi with the .280 as well, unless one thinks there is some magic to the brass that has a headstamp with .270 win on it. But again, my point was merely to provide an apples to apples comparison for maximum commercial loads.

Your previous post was a home run, I just think you may have misread mine. Perhaps I could have been clearer with where I was going with it.


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