Lyman Cast Bullet Handbook - The Firearms Forum

DixieLandMan · 11-14-2011, 02:14 PM

Ok, I've made my choice but wanted to know if there really is a significant difference in the 3rd edition vs. the 4th edition and if so, in what ways? Thank you!

JLA · 11-14-2011, 06:58 PM

the 4th will contain updated data for newer Cartridges, projectiles and powders..

DixieLandMan · 11-14-2011, 10:00 PM

Thank you, JLA. That is what I needed to know. Although I reload 'older caliber' weapons, I do have some older and newer powder. Thank you!

LDBennett · 11-15-2011, 07:12 AM

I do not know specifically about the Lyman manual but all the other producers of reloading manuals not only update them with newer cartridges but update even older data.

The means of testing for pressure have changed in the last decade or so. They use to use the mechanical crusher method where they used a special device attached to the barrel that diverted some of the gas to crush a copper slug. The slug was then compared to a calibration chart to get the "CUP" pressure. Today they use a piezoelectric device to measure the pressure directly in PSI by observation in real time on an oscilloscope. It turns out that there is no direct correlation between CUP and PSI as it varies from cartridge to cartridge and even from pressure level to pressure level. The PSI method is much more informative as you can see the pressure curve, not just the peak pressure result as with the CUP method.

This change in pressure measurement often dictates changes to time honored loads because something exists in the PSI data that may be dangerous that was not able to be seen in the CUP result, which only kind of represented peak pressures.

New manuals are GOOD!

LDBennett

11-14-2011, 02:14 PM	#1
DixieLandMan Senior Member Join Date: Oct 2011 Location: Alabama Posts: 603	Lyman Cast Bullet Handbook Ok, I've made my choice but wanted to know if there really is a significant difference in the 3rd edition vs. the 4th edition and if so, in what ways? Thank you! -->

11-14-2011, 06:58 PM	#2
JLA TFF Moderator/Host Join Date: Feb 2007 Location: Heart Of Texas Contributor Posts: 17,298	Re: Lyman Cast Bullet Handbook the 4th will contain updated data for newer Cartridges, projectiles and powders.. __________________ It takes 43 muscles to frown, 17 to smile, and 3 for proper trigger squeeze. The latest caliber or gear is no substitute for experience and skill. Rifles and cartridges don't make hits -- shooters do. Fact of life: After Monday and Tuesday, even the calendar says WTF!

11-14-2011, 10:00 PM	#3
DixieLandMan Senior Member Join Date: Oct 2011 Location: Alabama Posts: 603	Re: Lyman Cast Bullet Handbook Thank you, JLA. That is what I needed to know. Although I reload 'older caliber' weapons, I do have some older and newer powder. Thank you!

11-15-2011, 07:12 AM	#4
LDBennett Advanced Senior Member Join Date: Dec 2003 Location: Hesperia, CA Posts: 5,710	Re: Lyman Cast Bullet Handbook I do not know specifically about the Lyman manual but all the other producers of reloading manuals not only update them with newer cartridges but update even older data. The means of testing for pressure have changed in the last decade or so. They use to use the mechanical crusher method where they used a special device attached to the barrel that diverted some of the gas to crush a copper slug. The slug was then compared to a calibration chart to get the "CUP" pressure. Today they use a piezoelectric device to measure the pressure directly in PSI by observation in real time on an oscilloscope. It turns out that there is no direct correlation between CUP and PSI as it varies from cartridge to cartridge and even from pressure level to pressure level. The PSI method is much more informative as you can see the pressure curve, not just the peak pressure result as with the CUP method. This change in pressure measurement often dictates changes to time honored loads because something exists in the PSI data that may be dangerous that was not able to be seen in the CUP result, which only kind of represented peak pressures. New manuals are GOOD! LDBennett