The Firing Line Forums - View Single Post - Cartridge Length

rg1 · October 1, 2008, 09:27 PM

A difference in bullet shapes causes lots of questions about overall length in pistol and rifle. 9mm 124 gr. FMJ bullets I've used vary in their tip shape. Winchester has a more sharply tapered round nose and is why the factory seats them longer. MagTech round nose I've seen are a blunter shorter taper. Remington and Speer 9mm bullets have a little different shape too. That's one reason you see overall length variations in pistol and rifle.
Winchester .223 55fmj's and military 55fmj's are sharper pointed that most others and overall length for the sharper tipped bullets are 2.250" while other less pointed 55 fmj's recommended length is as short as 2.200".
One thing I've played with is using a factory cartridge to set the seater die just to see the outcome. I've put the factory cartridge in the press and screw the seater stem down to just touch the factory bullet. Then I try one seating different same weight bullets just to see what the overall length comes out to. As the seater stem touches the bullet on the ogive or taper of the bullet, you'll get different oal's and sometimes the oal matches the book for the bullet you've used. Feeding reliability in your pistol is the main concern plus you don't want to use max data and seat bullets deeper as pressure will increase.

October 1, 2008, 09:27 PM	#5
rg1 Senior Member Join Date: November 6, 2001 Posts: 1,131	A difference in bullet shapes causes lots of questions about overall length in pistol and rifle. 9mm 124 gr. FMJ bullets I've used vary in their tip shape. Winchester has a more sharply tapered round nose and is why the factory seats them longer. MagTech round nose I've seen are a blunter shorter taper. Remington and Speer 9mm bullets have a little different shape too. That's one reason you see overall length variations in pistol and rifle. Winchester .223 55fmj's and military 55fmj's are sharper pointed that most others and overall length for the sharper tipped bullets are 2.250" while other less pointed 55 fmj's recommended length is as short as 2.200". One thing I've played with is using a factory cartridge to set the seater die just to see the outcome. I've put the factory cartridge in the press and screw the seater stem down to just touch the factory bullet. Then I try one seating different same weight bullets just to see what the overall length comes out to. As the seater stem touches the bullet on the ogive or taper of the bullet, you'll get different oal's and sometimes the oal matches the book for the bullet you've used. Feeding reliability in your pistol is the main concern plus you don't want to use max data and seat bullets deeper as pressure will increase.