Minimum length for 9mm

**Yoder** · May 17th, 2009, 01:19 PM

I found the specs on min/max case length and on maximum cartridge length but not minimum cartridge length. Anyone have this information or could tell me where to find it? I'm just trying to get an idea how to set up my reloading dies, thanks.

**Yoder** · May 17th, 2009, 04:19 PM

nevermind, I'm a dumbass. It's right in my reloading manual. Thanks anyway.

**Flash** · May 17th, 2009, 11:42 PM

Please observe that the cartridge overall length is defined more by the volume inside the loaded case relative to the powder charge than by the particular mass of the bullet, though the bullet weight and shape are carefully calculated in to arrive at that figure.

Internal volume of loaded case with powder charge controls internal pressure-temperature and time/speed of rise of those two forces. (Like . . . "to KaBOOM or not to KaBoOOM, that is the equation" ).

The seating depth and the length, both, of the particular bullet defines the COAL. Loading it, you just have to work backwards, as it were, to arrive at the proper loaded volume. Since most reoladers are more concered with good loads than good math, the guys who wrote the load-chatrts have hired the mathemeticians to do all that work for us. It finishes as one figure, COAL.

Happy shooting.

Flash

**hgsw67** · May 18th, 2009, 06:28 PM

Hi Chris,
Just for comparisions, my Sierra manual gives the following C.O.A.L measurements for the following weights:
90 Grain JHP = 1.010"
90 grain FMJ = 1.020"
115 grain JHP = 1.050"
115 grain FMJ = 1.100"
125 grain JHP = 1.075"
125 grain FMJ = 1.090"
130 grain FMJ = 1.135"
HOpe this helps, if need be and your free this week let me know yo can come over to peruse what I have.
Harry
hgsw67

**Yoder** · May 19th, 2009, 01:13 PM

I found the info with my reloading dies. For tightgroup powder I think the min is 1.12 C.O.A.L. for the 115 gr FMJ that I'm using. I got my dies all set up and loaded some dummy rounds for reload practice. When I get some free time I'll start on figuring out the powder. I already know how much to load I just need to play around with the powder auto dispense and make sure it's accurate and consistent.