[PatMiles]

I realize that there is no way to convert PSI to LUP. There are maximums for PSI. Is there a maximum for LUP which should be avoided?

Pat

 

[alf174]

LUP is the acronym for ?????????

 

[threedeuces]

When talking to Alliant they said if it is a published load then it is a safe load.

 

[oz]

LUP CUP and PSI all measure pressure in a gun's chamber. Piezo quartz PSI measurement is much more precise. gives you exact pressure from when the primer is fired until the bullet (shot) leaves the barrel.

 

[Dr.Longshot]

LUP= Lead Units of Pressure.

Gary

 

[threedeuces]

Doesn't mean shit to someone who doesn't know shit about it.

 

[Kemper]

WTF

 

[JH]

If you don't know the difference, then, maybe, another K-80 is about to Blow-Up!

 

[Drew Hause]

Short version

There are three pressure measurement systems (lead crushers/LUP, copper crushers, and piezo), and two standard systems of measure units (USA/SAAMI and CIP/British/European) and two differing units (psi and tons and bar and Kg/Cm sq) within each system, different proof laws by country, and differing proof laws by age.
Unfortunately, there is essential NO formula to convert BAR expressed as LUP (CIP) to PSI (SAAMI). LUP + 1000 does not reliably predict the actual piezoelectric transducer measured pressure.
In 1989, all proof data was marked in metric using the BAR as the unit of measurement. The use of TONS per sq. inch was dropped. Under this system, 850 bar represented standard proof, with 1200 bar being special or magnum. 2 1/2" chambered guns are usually proofed 850 bar while 2 3/4" chambered may be proofed 900 bar or higher.

**650 bars is standard CIP (British and European) service pressure for shells designed for guns proofed at the CIP standard of 850 bars**

European (CIP) proof pressure of 850 kg per sq. cm. (BAR) = 13,920 psi proof pressure= 10,730 psi service pressure (SAAMI)

 

[bigbore613]

Just be careful! Jeff

 

[Avaldes]

Well at the risk of opening a can of worms, these different units(psi, CUP, LUP) are just different methods used to measure pressure. Pressure being a measure of force per a specific area...thus pounds per square inch. With sufficient understanding of the measurement techniques, it would be fairly straight forward to draft a conversion factor between them.

My cursory understanding is that LUP and CUP refer to the amount of linear crush that a lead or copper slug undergoes during a pressure event. It is certainly possible to measure and calibrate the pressure in psi required to achieve that crush. That conversion between units just isn't part of the normal knowlege base of shooters. PSI is a much less complicated method of measurement and it makes a lot of sense that the older methods should be phased out.

 

[Jeff K]

Why can't the powder mfn. just pressure test the recipe's in question . And list in PSI that seems to be what everyone wants .For years they continue to reprint the manuals I think it is time to convert every one to PSI.

 

[Redcobra]

When I see an LUP measurement I don't know what to think. Yeah it's published but that doesn't mean anything. I use tubes and know that 10K-10.5k psi is about the limit for my 20g tubes. But what is the LUP limit?

 

[timb99]

Jeff K, Converting all the LUP units to PSI would require the powder manufacturers to re-do all the pressure testing they already did.

That costs money.

In a perfect world, all the results would be in PSI, but I don't see them doing it any time soon.

Anyway, like it was posted above, if it's published, its safe.

Redcobra, I would recommend calling the powder manufacturers with yoru question. They may have an answer for you.

Avaldes, if I understand correctly, its been tried with no good results. And all the LUP data is old. Nobody uses it any more for new powder testing.