Hey guys--
I cast and shoot 9mm through my M&P and have absolutely loved shooting accurate bullets for less than a nickel a round. My first (and currently only) 9mm mold was the Lee 6 cavity 124 grain round nose tumble lube design. It was working pretty well in my short-barreled Shield, but when I went to the full-size, I'm getting leading that I can't seem to escape. I've checked all the usual culprits and ruled them out (bullets are not undersized, not being swaged by brass during seating/crimping, not too soft or too hard, not being fired too hot, not out of round, and I'm powder coating so it shouldn't be a lube problem).
As near as I can tell, the problem is that all my powder coating is scraping off the sides of the boolit before it reaches the end of the barrel, as I have moderate leading only in the last about 1.5" of my muzzle. The rest of the barrel is squeaky clean. Reading up, I'm far from the first person to have issues with this mold, even powder coating. I will note that I'm not getting tumbling or keyholing like some others have reported, and my rounds are very accurate. But the leading will not go away no matter what I try.
So I'm looking at trying a new mold.
Right now it's between the Lee .358" 105Gr SWC, or the Lee .356" 120Gr TC. I've been really happy with the 124 grain weight so far. The point of impact seems right on where it should be (my POI on 115 grain factory ammo usually seems low). I also like the idea of going from a round nose to a TC. Hopefully this gives me cleaner holes in the paper, since I'm primarily target shooting.
But the SWC design has the advantage of coming out of the mold a little larger, so I will probably not have to mess with the mold to get boolits big enough. It also lets me stretch my lead further since it's lighter, and therefore probably my powder will stretch further too, and I'll have more pleasant recoil. May also give me even cleaner holes in paper than the TC. My biggest concern here is that this bullet is too light to shoot accurately and/or give me a really low POI. I virtually never shoot further than 25 yards with my M&P though, so if it can be an accurate boolit out that far, I'm happy.
Looking for people who have experience with one or both of these molds to help me make a decision. All opinions welcome. Thanks!