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View Full Version : Max seating depth of the 9x19mm using flat based heavy for caliber boolits



Whistler
01-08-2015, 12:49 PM
Posted for reference, originally from the Cast Boolits Facebook group.

Original post:


Has anyone tried and measured what the maximum seating depth for the 9x19 is with a .357 lead bullet? Notice I wrote seating depth, not cartridge length.
For the 9x19mm revolver for competetive shooting you want as short a round as possible for fast reloads. You also want a bullet as heavy as possible since it gives less recoil at power factor 125. This turns into a problem as the 9x19 is tapered with thicker walls the lower you get to the bottom of the case, you don't want the bullet to get sized down. A bevel base or gase check bullet design is probably helpful, but it would be interesting to see figures for a flatbase bullet.


Answer from Glen E. Fryxell:

I believe that the Lyman 147 has a bevel base for exactly this reason. I haven't made the measurement you ask for, but I have done a lot with deeply seated heavyweight cast bullets in the .357 Magnum and the degree of taper varies considerably from one brand of brass to another. I assume this would also be true for 9mm.

My conclusion:

I just tried seating a Lee 358-150-1R sized .357 to a depth of .346" (OAL = 1.115"), meaning case mouth at crimp groove. Then I knocked it out with a kinetic bullet hammer. The first driving band (closest to the crimp groove) is still .357", the second .355 and the base band is .349".

I would not recommend a seating depth greater than .223" (easy to remember) in the 9x19mm with a flat base bullet. If beveled based, you can probably extend the seating depth with the length of the beveled base band.

However, this was using Norma brass (go Sweden!), so as Glen (https://www.facebook.com/glen.fryxell) Fryxell stated; other brass may (read "will") have other tolerances.

tazman
01-08-2015, 02:33 PM
For 9mm I regularly seat my heavy boolits to a depth of .300 to .350 using mixed brass and the boolit sized to .358.
The boolits used are 358212 and a discontinued Lee boolit 356-153-2R. Both are flat based boolits. The first is 146 grains. The second is about 155 grains with my alloy.
I use water dropped range scrap for my alloy giving a bhn of about 20 to help alleviate the swaging issue.
I haven't had a problem with either leading or accuracy. The heavy boolits are some of my most accurate loads in both my pistols and carbine.