Saami pressure higher for 270win vs 280rem?

[shortaction]

Been speculating about this for a bit.

Looking at my reloading manuals the 270win max loads are 62-63k psi while the 280rem loads are 57-58k psi. Now I've heard all the stories about remington loading it down for their model 740 auto loaders. But they run the 270win in these same guns?

So I've been wondering are there any other reasons for this such as do they make the brass stronger for the 270win, etc?

Otherwise is it safe to load the 280rem in a good quality firearm to the same pressures as the 270win? If you compare the two cartridges in reloading manuals they show a heavier load of the same powder for 270win using the same weight of bullet?

The 308win is about 60k psi max, the 30-06 close to that as well?

Guess my question is, what makes the difference? Brass, cartridge design which affects bolt thrust, etc?

[Pathfinder76]

I don't think there is a good reason for it. I don't think brass is an issue either.

[260 Rem]

It makes sense ---all things being the same/equal in these two different cartridges - that the 270 will develop greater pressure because the case capacity is less due to the smaller internal neck diameter.

[Leeper]

The chambering of the 280 in the autoloader has long been the accepted reason but, as the OP pointed out, they chambered the same rifle in the 270. Nonetheless, I suspect Remington felt the autoloader would be more reliable at lower pressures. There is no reason whatsoever that the 280 cannot be loaded to the same pressure levels as the 270. In fact, in a strong bolt action or single shot, almost any cartridge can be loaded to similar pressures assuming the use of modern brass. Leeper

[FCLightning]

Along these lines, I have often wondered what the performance of the 7x57 would be like if loaded to the same pressures in a modern bolt rifle.

[Pathfinder76]

Originally Posted by FCLightning

Along these lines, I have often wondered what the performance of the 7x57 would be like if loaded to the same pressures in a modern bolt rifle.

2850-2900 with 140's is easily attainable.

[Dick284]

30'06 and 308 are not loaded to the same pressures.
30'06 is a 50,000CUP cartridge
.308Win is a 52,000CUP cartridge.
The new standard of measure is now PSI, which can vary between cartridges, so equating things is a lot tougher.