PSI to LUP conversion.

[odean]

Stamped under the barrel of my Pietta shotgun is 2110 KG. If this is the proof in kilograms that translates to 4642 lbs. Shotgun data is usually stated in "lead units of pressure". Is there a conversion factor to convert LUP to PSI or PSI to LUP? Does anyone know what it might be or know where it might be found? The Navy Arms book that came with the gun has all of it's loading data stated in LUP. Any help will be greatly apperciated.

Thanks,

Oscar/NC

 

[DMURPHY317]

I'm not sure where to get the conversion info for LUP to PSI but I was wondering about your conversion of 2110 KG to 4642 LBS. If the 2110 KG is kilograms per square centimeter, that would equal 30,011 PSI not 4642. Double check what the actual units are for your proof mark to confirm this info.

 

[odean]

The only marks under the barrel are the 2110 KG which I assumed (I know about assuming but I did any way)and the mfg. code for 1978 and a few other marks that have no meaning to me what so ever. I didn't think about the proof being in sq. centimeters. I used 2.2 lbs. for a kilo and came up with the 4642. Since it is marked in kilos it stands to reason that the proof would not be in sq. inches, but sq. centimeters. In the Navy Arms owner's manual that came with the shotgun the loading data was generated by Lyman's Labratory and the disclaimer was to contact the gun mfg. for their reccomendations for loads. That got me nowhere. When I talked to Navy Arms they refered me to Sam Fadala's book on loading the BP shotgun. The owners manual calls for a max load of 102 gr. FFg and 1 1/4 oz. of shot. I just wanted to confirm a correct, safe, maxium loading for the gun.

Thanks,

Oscar/NC

 

[robinghewitt]

I don't think there is any conversion possible. LUP's is just a way of comparing loads fired from the same pressure gun, I don't think it has much meaning beyond comparing.

English nitro shotguns showed proof tested to 3 or 3.25 tons per square inch. This doesn't mean they were tested to that pressure, it means parliament decided on 3 tpsi and the proof house invented loads to produce that pressure.

I havent figured out if their loads gave an average or a peak pressure :: you can work out the average pressure from the muzzle velocity.