.45 Auto Case Dimensions Don't "Measure-Up"

slice38 · April 25, 2009, 08:02 AM

Brass cases that I've picked up from the range don't seem to meet the dimensional standards for the cartridge. OAL measures about 0.886-0.883 in. or about 0.012-0.015 in. shy of the book (0.898 in.). Even rim diameter measures 0.473 in. or about 0.007 in. shy. (And yes, I've checked my caliper).

Are these cases nevertheless safe and okay to reload?

Thanks,
Mike

Hommbs · April 25, 2009, 08:40 AM

They're fine.

harry carey · April 25, 2009, 01:31 PM

SAAMI specs are either maximum or minimum. your mileage may vary.

brickeyee · April 25, 2009, 01:48 PM

The dimension do not apply top a fired case, but a sized case.

When straight wall cases expand to chamber size they often get shorter.

Sizing them will make them longer.

slice38 · April 25, 2009, 05:24 PM

Folks,

Thanks for the comfort level. I am absolutely new at this and am about to start loading .45 auto only at first (when I get my "backordered" supplies). Later, I will try the .454 and 9mm..

I'm sure I will have a lot of ridiculous questions coming at you but I will try to find my answers on the search feature first. This if a remarkably good forum.

Mike

Stumper · April 26, 2009, 01:03 PM

"The dimension do not apply top a fired case, but a sized case.

When straight wall cases expand to chamber size they often get shorter.

Sizing them will make them longer"

Additionally, the .45 auto and other mild pressure straight cases which headspace on the case mouth are known to actually foreshorten slightly in repeated firings and resizing cycles. -No worries about safety but also no real need to trim cases in some chamberings.

April 25, 2009, 08:02 AM	#1
slice38 Member Join Date: April 14, 2009 Posts: 16	.45 Auto Case Dimensions Don't "Measure-Up" Brass cases that I've picked up from the range don't seem to meet the dimensional standards for the cartridge. OAL measures about 0.886-0.883 in. or about 0.012-0.015 in. shy of the book (0.898 in.). Even rim diameter measures 0.473 in. or about 0.007 in. shy. (And yes, I've checked my caliper). Are these cases nevertheless safe and okay to reload? Thanks, Mike

April 25, 2009, 05:24 PM	#5
slice38 Member Join Date: April 14, 2009 Posts: 16	Thanks for the comfort level. Folks, Thanks for the comfort level. I am absolutely new at this and am about to start loading .45 auto only at first (when I get my "backordered" supplies). Later, I will try the .454 and 9mm.. I'm sure I will have a lot of ridiculous questions coming at you but I will try to find my answers on the search feature first. This if a remarkably good forum. Mike

April 25, 2009, 08:40 AM	#2
Hommbs Senior Member Join Date: June 1, 2005 Location: La Puente, California Posts: 102	They're fine.

April 25, 2009, 01:31 PM	#3
harry carey Member Join Date: April 25, 2009 Location: georgia Posts: 67	SAAMI specs are either maximum or minimum. your mileage may vary.

April 25, 2009, 01:48 PM	#4
brickeyee Senior Member Join Date: December 29, 2004 Posts: 3,351	The dimension do not apply top a fired case, but a sized case. When straight wall cases expand to chamber size they often get shorter. Sizing them will make them longer.

April 26, 2009, 01:03 PM	#6
Stumper Senior Member Join Date: June 15, 2008 Location: Colorado Posts: 438	"The dimension do not apply top a fired case, but a sized case. When straight wall cases expand to chamber size they often get shorter. Sizing them will make them longer" Additionally, the .45 auto and other mild pressure straight cases which headspace on the case mouth are known to actually foreshorten slightly in repeated firings and resizing cycles. -No worries about safety but also no real need to trim cases in some chamberings.