Anyone know the difference (and why) for maximum load pressures?
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Anyone know the difference (and why) for maximum load pressures?
CIP is continental and SAAMI is US. They are measured slightly differently and the max pressure for some cartridges may differ as I understand it.
GPM.
They definitely do differ. That was why I asked.Quote:
Originally Posted by grandpamac
In the 223rem CIP is 7000psi higher then SAAMI, and in the 308win CIP is 2000psi lower???
CIP is not measured in PSI but in M Pa or Bar so they have been converted. The US is the only country still using PSI. There are good descriptions on the differences on the net. For many years pressures were measured in Copper Units of Pressure formally called PSI (pounds force per square inch often abbreviated). these are different as well with no simple conversion.Quote:
Originally Posted by Shearer
GPM.
With high pressure air tanks, there is a different standard in the US vs Europe too.
Can't remember which way around it is... Either it's the US testing bottles to a higher pressure (like 50% over what they're rated for) which freaks out the Europeans who therefore don't allow US tested HPA bottles to be used (fearing the testing might somehow compromise the bottles)... Or the US testing isn't high enough pressure and the Europeans therefore aren't convinced US tested bottles have demonstrated they can withstand potential mishaps.
Either way, different side of the pond, different standards. CIP is just the standard to which European firearms get proofed - in different units and using different equipment. That might require a CIP stamped firearm to have been tested with a proof cartridge that's hotter than that same cartridge would need to be, if it were submitted to SAAMI.
Cip our cup? Cup is copper unit of pressure I believe.
Nevermind I see a good answer above now
I think the units they are measure in are irrelevant to what I am talking about. The point is, these are maximum pressures for operating in small arms. Why does one think it is safe to operate at a much higher pressure than the other? and vice versa in other cases? It seem like an industry double standard.
Unless you have some very special test equipment its kinda irrelevant anyway is it not?
Not a double standard
Just a different standard
Like people continents are allowed to dissagre also
Looking at that it appears Cip have raised it the the same as 5.66nato so that using that ammo in 223rem would be safe....but I speculateQuote:
Originally Posted by Shearer
I am not losing sleep over this or anything but when you use Quickload or GRT in developing a load it can make quite a difference to where you think a safe maximum might load be.Quote:
Originally Posted by veitnamcam
I understand you can have different standards, but it is not consistent when one cartridge is rated at a higher maximum pressure by one organization but another cartridge is rated lower. I assumed these figures were come to by scientific testing. Science is universal and it shouldn't matter what continent you are on.Quote:
Originally Posted by akaroa1
I think we need to remember that these are different standards measured with different equipment in a different way. We can't just convert one to the other and expect the same result. We are not talking about science but about measurement. with the differences in measurement methods I would be surprised if they were the same. Non US cartridges are often chronically underloaded in the US so the differences in these can be vast. To me it is a non issue.
GPM
Greetings,
I may have stumbled over the big difference with the .223. Much of the sporting .223 ammo in the US is shot in semi auto rifles where port pressure is important. On the continent this is not the case so the ammo may be loaded hotter. Military ammo works to a different pressure system and the chambers are slightly different. Just my thoughts and I have not dug into it.
GPM.
That's a fair point but not quite correct - Euro standards for cylinders have gone to ISO which has superseded the earlier standards. The US are still using DOT approved design standards, and there is a rigmarole to cross them over. In NZ we insist on destroying the protective coatings on our cylinders by smacking more marks on them like LAB approval numbers, which some jurisdictions then class as a unregulated marking and then condemn the cylinder! The issue isn't in the testing, all cylinders are given specific testing schedules and procedures as part of the design standards it's just the design standards that are acceptable in each jurisdiction differ. The cylinders themselves come out of the same plants, off the same production tooling and the only thing that changes are the roll stamps that mark them and minor things like the neck thread sizes.Quote:
Originally Posted by Pommy
As far as the ammo, testing standards are pretty much the same, the design standards call for a specific testing method using calibrated equipment that produces a result that must be within a specific range to be acceptable - if you use different equipment you get a different result and while it might produce a 'low' seeming pressure in numbers it might not be safe to shoot it in a firearm.