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Old November 21, 2012, 11:57 AM   #8
Bob Thompson
Senior Member
 
Join Date: December 28, 1998
Location: riverdale,ut,usa
Posts: 136
Update: thanks to all who replied. I do not have go-nogo guages but after checking and measuring very accurately the fired and unfired cases I find with these Federal Blue box 175g. cartridges they are well under what four of my reloading manuals call on shell specs. Here is my findings:

From the manuals: OA length: 2.235 My cases both fired and unfired: 2.225
" " " Head to neck: 1.895 " " " " 1.875
" " " Base diameter: .471 " " " " .464
Naturally the neck is slightly bigger after firing.

Now my measurements are pretty accurate but even if I was off slightly they show a consistant difference and I believe Federal produces these cartridges well under reloading specs and pressure to chamber easily in the many different chambers of mass produced military rifles yet still be safe. I will be checking some other cartridges from Midway in the near future but I believe what is happening is when firing, with a fairly heavy firing pin spring in most military rifles, the case is moving forward the .010 I'm seeing in the primer extrusion. As you can see in my fired cases the base show no signs of high pressure but just the opposite, a case that feeds easily. With my AR and M1 Garand I'm reloading for I use RCBS small base dies to accomplish the very same thing. I believe I'm safe here but am I assuming too much and thanks again guys?
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