One of my guns has a tight chamber. I heard about the Lee undersized sizing die, but can't seem to find any available.
Does anyone know of a similar die from a different manufacturer that would also work?
► Due to the construction of the standard Lee 9mm Sizing Die, I believe all cases come out under-sized. Lee makes a good die, but they also prevail in keeping their costs low. The 9mm case represents a unique design problem. Unlike 45ACP, 40 S&W, 38Spcl, 357Mag or other common straight-walled cases, the 9x19 Luger case has a
taper. If Lee were to use a tapered carbide their cost would go up considerably. So I believe they use a non-tapered carbide ring, which works terrifically well, but leaves the 9mm case slightly undersized. SAAMI defines maximum case dimensions, and so being undersized is simply not an issue.
► If you are having issues chambering your finished rounds, due to the
tapered 9mm chamber I suggest you also check your: 1)
Taper Crimp and 2) your finished cartridge OAL with respect to your barrel's maximum allowable OAL. Many barrels with "tight chambers" also reduce the
freebore, thus making the reloader use OALs
shorter than those listed in some reloading manuals. The OAL shown in your reloading manual is
NOT a recommended cartridge OAL. It is merely a
report of what the test lab used. You can only safely use their OAL with that specific barrel and that specific bullet. Every other conceivable bullet-barrel combination has to be checked on an individual basis.
You may be OK if your barrel looks like the one from the test lab....
Hope this helps.
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