Printable View
If you increase pressure , you need a smaller case head to withstand the excess pressure than what is generated by a magnum case.
So since case capacity is the limiting factor ( standard 7mm backcountry case close to 280 rem volume) the only thing that can rise pressure ( I presume) is loading with faster burning powder …?
If you run out of capacity before a powder gives you the pressure you want then yes, switch to a faster powder. But if you take a few samples of different factory loadings for different cartridges, a lot of them are nowhere near to 100% fill and you can hear the powder shaking around. If you were to take one of those loadings with spare case capacity, you could quite easily keep filling them with the same powder to get up to the required pressure. That same powder is going to burn more thoroughly and completely like you'd expect a faster powder to, because the chamber pressure is so much higher.Quote:
Originally Posted by Friwi
See screenshots on the other thread (https://www.nzhuntingandshooting.co....96/index5.html). GRT suggests it's entirely possible (and I'd put money on it being the case) that they're just using a stiff dose of Re26... Which is not something you'd normally consider to be a "fast burning" powder. Yet 80,000psi gives it a 100% burn (for whatever that's worth) in a 12" barrel.
Can simply be more of a slower powder. If you are being limited by pressure and not capacity usually adding powder is a better method once the pressure ceiling is removed.Quote:
Originally Posted by Friwi
Ok so now i need to buy some new brass / alloy cases and possibly some slighly faster powder for my 243 and 358win and they will get an extra 200fps.
will be interesting to see what happens as the new tech cases start to trickle down into existing calibers. all the reloading books will need to be redone.
Fasinating to see that they are clamining the limiting factor is brass not the existing actions.
Z