BruceB
11-12-2006, 11:09 PM
Today my wife exhumed my old Speer #7 Manual from some dusty nook. On the flyleaf, I had written: "BruceB, Yellowknife NWT, August 1968" ...so, I've owned it for a while.
Reading through the instructional part of the manual, I was impressed by how little has changed. Articles by Nonte, O'Connor, Grennel, Forker, Powley etc still make excellent reading.
Then I came across a little gem from CCI, that being a table containing the foot-pounds of force generated by each of their various types of primers. This data is obviously pretty old, but the types are exactly the same, and I've never noticed any change in the CCI's I've used in the meantime, which amount to hundreds of thousands over the decades.
"A uniform initiating blow of 0.45 foot pounds was used to fire all primers. Values are energy imparted to a piston in a test cylinder."
"By actual copper crusher test, the CCI 250 Magnum primer produces a pressure of 25,000 psi when fired in a small closed chamber. This is an essential function of a primer in igniting smokeless propellant powders."
Now, the figures provided from CCI for energy developed by each type of primer:
Small Pistol #500 ----------------5.50 ft lbs
Small Pistol Magnum #550-----8.80
Small Rifle #400-------------------6.00
Small Rifle Magnum #450--------7.20 (lighter than sm pistol magnum! BB)
Large Pistol #300---------------- 7.10
Large Pistol Magnum #350------9.15
Large Rifle #200------------------9.20
Large Rifle Magnum #250--------9.45
Interesting, yes????
Reading through the instructional part of the manual, I was impressed by how little has changed. Articles by Nonte, O'Connor, Grennel, Forker, Powley etc still make excellent reading.
Then I came across a little gem from CCI, that being a table containing the foot-pounds of force generated by each of their various types of primers. This data is obviously pretty old, but the types are exactly the same, and I've never noticed any change in the CCI's I've used in the meantime, which amount to hundreds of thousands over the decades.
"A uniform initiating blow of 0.45 foot pounds was used to fire all primers. Values are energy imparted to a piston in a test cylinder."
"By actual copper crusher test, the CCI 250 Magnum primer produces a pressure of 25,000 psi when fired in a small closed chamber. This is an essential function of a primer in igniting smokeless propellant powders."
Now, the figures provided from CCI for energy developed by each type of primer:
Small Pistol #500 ----------------5.50 ft lbs
Small Pistol Magnum #550-----8.80
Small Rifle #400-------------------6.00
Small Rifle Magnum #450--------7.20 (lighter than sm pistol magnum! BB)
Large Pistol #300---------------- 7.10
Large Pistol Magnum #350------9.15
Large Rifle #200------------------9.20
Large Rifle Magnum #250--------9.45
Interesting, yes????