Because of the physical limitations of chemical propellant.
The bullets fired by the .30-06 are infinitely better than they were 100 years ago.
Agree! The only way to drastically improve the cartridge�s performance (with current powders) is to increase pressure. Many older guns would not happily digest dramatically higher-pressure loads; they suffer heart-burn and so would the shooter. In fact, current guns would not happily digest them either.
I would like to see that statement qualified with model numbers, math, and source data.
Like that's going to happen
The 30-06 is registered with SAAMI at 60,000 psi max average and proof between 78,000 and 84,000 psi.
The 30-06 case head, the 1889 7.65x53mm Mauser case head when built with a large primer pocket is good for 65,000 psi in production, and reloaded at least once without primers to falling out.
I am not aware of any 30-06 rifles that are safe at 60,000 psi, but not at 65,000 psi.
There is much safety margin in the rifles, and little in the brass.
![[Linked Image]](http://i757.photobucket.com/albums/xx220/ClarkM/DSCF0032bulletpinch308brass243chambercropped.jpg)
The brass is the weak link.
Focus on the brass.
30-06 rifles being old is a red herring.
After a lifetime of living in fear and ignorance spawned by mediocre load books, these are concepts difficult for some old men to internalize.... they don't get it.
