Author Topic: Rifle Magazine - CUP and PSI the same (Read 871 times)

Nobody · « **on:** February 21, 2004, 12:07:01 PM »

Picked up the March 2004 issue of Rifle Magazine. In answering a question regarding pressure tolerance for Model 1874 Sharps rifles (page eighteen), the editor states "In the .45-70, CUP and psi are the same."

New one on me.

The article also goes on to say that top-end loads for the 1895 is "generally considered" to be 43,500 psi.

Hmmm.

BTW, everytime I tried to type "18" a 1 :grin: displayed.

MarkJ_Thompson · « **Reply #1 on:** February 21, 2004, 01:11:47 PM »

http://www.reloadbench.com/gloss/cuppsi.html

MJT

Don't believe everything you read.

MePlat · « **Reply #2 on:** February 21, 2004, 01:22:18 PM »

This is where thing need to be explained more so they will be understood by the populace. Most don't understand the presure thing.

1. A Piezo Transducer Pressure testing barrel and a Copper Crusher test barrel is calibrated with the same calibration ammo.

2. The difference is that with a Piezo Transducer method will show pressure climb, peak pressure, and the pressure time factor.

3. The Copper Crusher piston method is mostly read at the case mouth and records peak pressure at the source of the position of the piston.

4. The piezo Method is read from the body of the case mostly as I know of it.

If the same calibration ammo is used for both it would have to be extremely similar or so it would seem so in my mide.

Like arguing over what is more correct 1 inch, 25.4 mm or 2.54 centimeters. But I am sure there will be many posts and discussions over this statement by some writer that took for granted that everyone knows about the testing methods used by the ballistic labs.

jaycocreek · « **Reply #3 on:** February 21, 2004, 01:41:09 PM »

MePlat-Good to see ya.

43,500 PSI or 40,000CUP Both are indicater's of Be Carefull

Any responsible reloader use's these indicater's to see where to Stopin there reloading. Both are great if ya have one.But most don't,so that's where a Chrono comes in with resposible Data off of a Test Barrel.

Best of luck.Jayco.

Red Neck64 · « **Reply #4 on:** February 21, 2004, 02:08:52 PM »

The shape of the primer does it for me,it tells me when to back off.

Dali Llama · « **Reply #5 on:** February 26, 2004, 02:25:39 AM »

Quote from: MePlat

I am sure there will be many posts and discussions over this statement by some writer that took for granted that everyone knows about the testing methods used by the ballistic labs.

:oops: :oops: :oops: