Interesting question and replies.
A max load is spoken of so much, yet it is such an illusive thing. Who's max load?
For as long as I can remember, a 180 grain bullet in loaded 30-06 ammunition, is always shown as giving 2700 fps, regardless who makes the ammo. Unless they have greatly changed in the last few years, most loaded ammo will give in the neighborhood of 2550 fps, 180 grain bullet, 30-06.
I have tested two 30-06 rifles, one a Remington 30 Express, with a new 24" barrel. The other is a Swede with a 24" barrel. In every load tested, the Remmie always gives about 75 more fps than does the Swede. Yet, I can safely load the Swede to actually higher velocity, than the Remington will give, with a grain or two more in the Swede.
Loading books are the same, always giving 2700 fps for the 180, 30-06. I saw one loading book that showed 54 grains of 4350 as giving the 2700 fps. I tested 56 grains of 4350 in the Remington, which always gices the best velocity, and it averaged 2574, over the Oehler 33! So what did their load of 54 grains give? Probably a doubtful 2475, a far cry from 2700, but that was their maximum load! If this was the book you went by, and never exceeded their max load, you would have a very feeble 30-06, would you not?
I load very similar to the way Stubblejumper described. I take my loading outfit to the range and load as I shoot. I use the same case over and over. with a slow powder like 4350 and a bottle neck case, I don't see any point in making the increments less than one grain. Thus, I load a cartridge with a charge I know is safe and fire it. Then in the same case, I load one more grain of powder. Shoot, look for all signs of pressure. First, carefully note the pressure require on the bolt handle to lift it. Then the primer exam, but primers are not a very good method of determing pressure, because of the variance in primers. Look at the case head to see if there are marks from the bolt face, which would indicate high pressure. Look at the case head to see if it has a shiny ring near the outer rim. If it is shiny it means the case was stuck in the chamber and the bolt rotated a bit before the case came loose. Case sticking, high pressure.
Then, the final test. I seat a primer in the fired case, while taking careful note of the pressure required to seat it. If it goes in easy, or easier than it did the time before, then your safe pressure was exceeded, and the primer pocket was enlarged.
I will now drop back a bit, and that is my maximum load. As a point of interest, the load I settled on after doing this, gave an average velocity of 2810 fps. No, I will not say how much 4350 it took to accomplish that, but I have a safe load which I have used extensively, and also have a peppy 30-06.
That safe load in the Swede will stick the bolt on the Remington.
I have said this on these postings before, but I think it is worth repeating, to show how a well bedded and tweaked rifle, will shoot virtually any ammo accurately.
While I was working this load up in my well tuned Swede, I fired five loads, with the fifth load having 4 grains more of powder, than the first load. When I looked at my target at 100 yards, the five shots, each with a grain of powder different than another, made a group of 1¼ inches!
