Maximum CUP for the 222?

Cleftwynd

Cleftwynd

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Does anyone have a source that states the maximum CUP for the triple deuce? I think max PSI is 48,000, but lots of my older data gives pressures in Copper Units of Pressure and they are all over the map, from 36,000 to 46,000 and I would like to know a stated CUP max for the cartridge.
 
I try to load my practice .223/5.56 ammo for my AR15 rifles to this same pressure range to make the brass last longer. Meaning 5,000 psi below the max rated pressure for the .223/5.56, I had a .222 and the brass lasted forever when not abused.
 
Cleftwynd said:
... I would like to know a stated CUP max for the cartridge.
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Why on earth would you want that? CUP was and is a quasi-quantitative bastardization of a measurement system. It was 100% obsolete the second the pressure transducer was invented, and that was half a century ago.

The CUP numbers you found are all over the map because CUP in an inherently unreliable and inconsistent system. Throw them away for good and move onto numbers that mean something.
 
So I know how close to the maximum pressure a load is that is listed in reloading data. That's the only reason.

In fact, even hodgdon's website shows many load pressures in CUP.
 
BattleRife said:
Why on earth would you want that? CUP was and is a quasi-quantitative bastardization of a measurement system. It was 100% obsolete the second the pressure transducer was invented, and that was half a century ago.

The CUP numbers you found are all over the map because CUP in an inherently unreliable and inconsistent system. Throw them away for good and move onto numbers that mean something.
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I'm 65 and grew up with Copper Units Pressure or CUP and even today PSI reading are like reading Greek. As an example both the .223 and 5.56 are rated for the same pressure of 52,000 cup or 55,000 psi. then to confuse the issue you also have the European CIP NATO pressure of 62,000 psi taken at the case mouth which is the same exact pressure as the SAAMI cup and psi pressures.

It was like being stationed in Japan in the military and growing up with MPH and suddenly owning a Japanese car with a speedometer in kph. It took two speeding tickets on base to help convert my brain to the silly metric system.

Bottom line, understanding the PSI transducer method depends on your age and the ability to teach old dogs new tricks. Besides I would rather be going 60 mph than 100 kph and thinking I'm approaching warp speed.

Signed bigedp51 the old dog.
 
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I wonder why the 223 is rated at 55,000 and the 222 at only 50,000. There are many cartridges that don't make sense to me as why they are rated much lower than a similar round.
 
Cleftwynd said:
I wonder why the 223 is rated at 55,000 and the 222 at only 50,000. There are many cartridges that don't make sense to me as why they are rated much lower than a similar round.
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Yup.

I think the older ones are rated lower, pretty much across the board. Like the 30-06 and it's offspring the .270 being rated 5, 000 psi more.

I was just looking at reloading data from Nosler as well last week; their energy levels for 35 Whelen loads were pretty much across the board HIGHER than their energy levels for 9.3 x 62. Apparently the 9.3 x 62 being both a larger case AND pushing bigger bullets doesn't compute to simply being more powerful according to Nosler.... I reload for both, I know otherwise.
 
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