The Firing Line Forums - View Single Post

SL1 · September 28, 2013, 09:16 AM

The manuals that list pressures and velocities for guns that are NOT test barrels are actually giving "apples & oranges" data. The pressures are from the test barrel, while the velocities are from the stated gun. The idea is to provide handloaders with a realistic expectation of velocity for the loads listed. When the test barrel velocities are given, they are almost always higher than achieved in commercially produced guns you buy at a gunshop. (And, some companies probably don't want handloaders trying to duplicate the test barrel velocities in their own commercial guns.)

As for your question, I think that most manuals are now based on pressure-tested data. However, even some of those may contain a little old data that was NOT pressure-tested when you look at some of the older, out-of-favor cartridges like the .30 Herrett.

And, while companies like H.P. White will test your handloads for a fee, that testing is done in THEIR pressure barrels, NOT your gun. About the only way to get the pressure from your own gun is to use the Pressure Trace equipment. But, then there is the question of calibrating that equipment, so the numbers in your own gun will always be somewhat in question.

SL1

September 28, 2013, 09:16 AM	#7
SL1 Senior Member Join Date: November 8, 2007 Posts: 2,001	The manuals that list pressures and velocities for guns that are NOT test barrels are actually giving "apples & oranges" data. The pressures are from the test barrel, while the velocities are from the stated gun. The idea is to provide handloaders with a realistic expectation of velocity for the loads listed. When the test barrel velocities are given, they are almost always higher than achieved in commercially produced guns you buy at a gunshop. (And, some companies probably don't want handloaders trying to duplicate the test barrel velocities in their own commercial guns.) As for your question, I think that most manuals are now based on pressure-tested data. However, even some of those may contain a little old data that was NOT pressure-tested when you look at some of the older, out-of-favor cartridges like the .30 Herrett. And, while companies like H.P. White will test your handloads for a fee, that testing is done in THEIR pressure barrels, NOT your gun. About the only way to get the pressure from your own gun is to use the Pressure Trace equipment. But, then there is the question of calibrating that equipment, so the numbers in your own gun will always be somewhat in question. SL1 Last edited by SL1; September 28, 2013 at 09:22 AM.