Ackley gives source data.
Modern load books are lawyer-ed up recipes and made up wife's tales.
Here are some examples:
P.O. Ackley "Volume I Handbook for Shooters & Reloaders" 1962
If any measurable increase in the diameter of the rim of the case is noted, we consider that pressure excessive and reduce the charge about 6% and list it as a maximum load in our loading table. There is no reason why the handloader cannot use this same procedure himself and determine whether or not the loads he is using are safe and practical for use in his rifle...
Vernon D. Speer, February 6, 1958"
I actually use 4% margin for extreme powders for my hunting loads
P.O. Ackley 1966 "Handbook for Shooters and Reloaders Vol 2"
"..30 cal barrel pressure barrel was fitted to the test gun, but theneck and throat was enlarged to accept the 8mm bullet, with the boreremaining the standard 30 caliber. A Remington factory 30-06 cartridgewith the 150 gr bullet had been tested and previously gave 57,300 psi, for a velocity of 3030 fps. The the bullets were pulled from two more Remington 150 grain cartridges and were replaced with 8mm 150 grain bullets. To everyone's surprise, although the velocity was rather erratic, these loads averaged 2901 fps, with a pressure of 40,700 psi."
The .458" 405 gr bullets swage into my .406" 410 bore.
"Speer 12" 1994:
Some bolt-action and single-shot rifles have been chambered for this cartridge. Reloaders can sue spritzer-type bullets in these rifles, but should keep the weight to 150 grains or less. Heavier spritzer bullets cannot be drive fast enough in the 30-30 to expand reliably. We are occasionally asked if the 30-30 can be loaded to higher velocities in a modern bolt action like the Remington model 788. The answer is NO! The 30-30 case is an old design with relatively thin walls. Attempting to load "hotter" would risk a dangerous case failure.
I have tested many brands of 30-30 brass, and I have yet to find any brass like they describe. All the 30-30 brass I test will go to ~ 90kpsi Quickload before flowing. And that is in a break action 30-30.
"Sierra 4th" edition handgun reloading manual 1995
Utilizing a roller block system similar to that still used in the H&K series of semi automatic and selective fire rifles, the Vz52 is an extremely strong pistol. In recoil operated pistols, such as the Tokarev, starting loads shown should be considered a maximum.
I have tested many CZ52s and Tokarevs and I have yet to find any examples like they describe where the CZ52 is stronger. The weak link is not the locking system, it is the wide variation of RC hardness on the CZ52 barrels coupled with paper thin chamber wall of the CZ52 over the roller relief cut.
The word 'forum" does not mean "not criticizing books."
"Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist.
Are we a nation of competing ideas, or a nation of forced conformity of thought?
Last edited by Clark; February 28, 2013 at 11:51 AM.