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View Full Version : Bottleneck vs. straight case



OlDeuce
04-28-2017, 09:03 PM
My question to you gents is ... As the taper of a Bottleneck case decreases closer to a straight case ,does CUP pressure fallow in
the same percentage ????

Ol Deuce

17nut
04-28-2017, 09:39 PM
WUT???

Are you trying to say that the pressure in the narrow end of a baloon is less than in the bulby?
And if you make it cylindrical pressure will rise in one end?

Gas is a funny thing and it will dissipate to every nook and cranny, thus making internal pressure the same everywhere in the cartridge, no matter the shape.

What is going on and might throw you off is the fact that given a bigger bore the pressure has a larger area to work on and thus transferring more energy for a given pressure.

1lbs/sqinch measured over a square inch is 1lbs of load.
But 1lbs/sqinch measured over 100sqinch is 100lbs of load.
No pixie dust or other magic, just a larger area for the force to work on.

So a 100gr 22cal bullet pushed by 1000psi compared to a 100gr 50cal bullet at 1000psi is a given. The larger bullet gets a bigger kick in the butt.

OlDeuce
04-29-2017, 01:16 AM
17Nut.........Thats a cool way to describe pressure! If the given pressure using slower powder It burns down the barrel pushing the boolit..and a fast powder is all at once?????? Just trying to get my thoughts as the effects of slow powder on a big bore over fast powder on the same big bore??

Thanks
Ol Deuce