Hi-tek working better for some calibers than others?

[fifteenfifty]

I've used Hi-Tek with great success on 357 and 44 Mag. But I'm getting light leading -w- 9mm. The same projectiles do fine with "traditional" lube. I'd honestly have thought nothing could be more challenging to the coating than full-house 44 Mag. So Im at a loss. Anyone else faced this?

[Ia.redneck]

My experience has been 9mm and Hitek need a HARD alloy

[Michael J. Spangler]

Same as above.

9mm dies tend to under size bullets. Expanders are for .355 or .356 bullets.
If you use .357” without a proper expander you end up with enough neck tension to squish the bullet down. Ending up with a way undersized bullet.
Then the normal issues show up. Tumbling. Leading.

So counter this with an oversized expander or a water dropped and aged alloy.

You can test by seating a bullet and pulling it. If you undersized or crimped through the coating you need a harder alloy or less crimp.