So, being new to casting and reloading, I recently got all the necessary equipment to do both.
I did not research the Lee TL designs well enough to find out that the 356-124-2R mold is (apparently) a problematic mold for most 9mm handguns.
I cast my boolits from range scrap, and powder coat in eastwood powder. I size them in a lee 356 sizer.
I use the standard Lee 9mm die set with 3 dies.
I shoot the H&K P30L with a tactical barrel.
My first tests was, and still is, ALL over the place. Major keyhole problem, and no precision whatsoever.
I tried to remove the Lee FCD to no effect.
I then tried to load the cast boolits without sizing at all, still no joy.
I then slugged the HK and found that it measured out at 0.359 - 0.360!! Holy cow!
The boolits I pulled after seating them where swaged down to 0.355 - 0.356 - no wonder they where all over the place.
I have ordered a S&W 38 expand plug for the Lee 9mm powder through expand die to avoid the brass casing acting as a sizer.
Now - is there anything else I should do with a 9mm bore the size of a battleship cannon? I would like them to hit the rifling at 0.359 - 0.36+. I have concerns that the TL356-124-2R has to little surface to grip the polygonal bore because of the design with many lube grooves. Any input is welcome.