Originally Posted by
Berserker
Ya they have less camming, and this may help. But I would think this would only be needed on higher pressure loads.
You're confusing yourself. The extraction camming action of a bolt action is not the same as the leverage advantage gained to aid in closing the bolt on a slightly oversized cartridge.
Load is irrelevant. If the round is a little oversized, the pump gun doesn't give you the leverage advantage to CLOSE the bolt. A slightly oversized round might actually open easier after firing compared to how it closed when loaded.
If you can't "sneak it closed," then your rounds are oversized. Whether that's long on headspace or fat on base diameter. A guy should be able to close the action just as easily when loaded as when empty - with just a slight bit of additional felt resistance.
Originally Posted by
Berserker
Why bother owning both dies? Why not just use small base dies for everything?
Making small rounds to fit a small chamber might leave the rounds undersized for a larger chamber. This over works the brass for that rifle, and leaves the cartridge with excessive "slop" in the chamber - and a major driver of precision is consistent and concentric positioning of the bullet in the bore axis, centered and true, when fired. If you're undersizing the brass, it'll lay or wedge to one side of the chamber and may not center itself as well as if it were properly sized. See my description above (again) in my other posts describing how this can be managed, ONLY if the chambers match for headspace.
Originally Posted by
Berserker
Again, wouldn't small base dies, be smaller than factory, which are built in any rifle? Though at lower pressures.
No idea what you meant to say here, as it reads like gibberish to me. A small base die is needed only when the cartridge is forced into an interference fit when chambered. As described repeatedly above, the base is one of the control points to ensure the cartridge is centered in the chamber, so the bore is released cleanly on the bore axis. So often the base is the tightest dimension on the ammunition - especially with a tapered body cartridge like the .30-06. This is what creates that resistance when you're trying to close the slide, and what a small base die can correct.
Small base dies have a purpose. Failing to understand cartridge-to-chamber fitment or firearms action design does not negate the purpose or advantage of a small base die for applications it is needed.
