My issue w/ TL bullets, shooting them unsized, is lack of uniformity. Your bullet dia will change w/ the casting/alloy temps. You are pretty much stuck w/ an Alox type lube. Using a luber/sizer gives you uniform sizes, improtant for proper neck tension & consitant bullet release, & the choice of many bullet lubes. Yes, bullet lubes matter for both leading & accuracy.
If you don't like the idea of nose punches & deformed bullets then get a Star/Magma sizer. They size nose first & use one size (i use two diff) top punch. I find the luber/sizer just easier & faster too. No multiple stgeps, no drying bullets, no sticky Alox mess. To each his own, but I started w/ the Lee pan lubing/hammer punch, then a Lyman 450 now a Star. The Star is the only way to go for a serious caster, shooting 1000s of bullets a year. You can easily & cleanly do 1200 bullets per hour w/o breaking a sweat.

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NRA Cert. Inst. IDPA CSO