I just got a new 5-cavity aluminum mould for a "fat" 314299. Cleaned and broke it in according to the directions, then proceeded to cast. I'm sorry I can't tell you what the alloy was. I'm about out of wheel weights, so I have been using some odds & ends that I picked up over the years. Some ingots were marked "WW & Lino", some "WW & solder", etc. As a comparison, a 45 SWC that weighed 205 grains out of 50-50 WW & lead weighs 199 out of this mix.
Anyway I was casting along and was getting a lot of rounded bands, especially in the middle cavities. I thought the venting looked "minimal", but some antique moulds work fine with smooth surfaces. As a test, I decided to fill the middle cavity first, and work my way out, instead of my usual from one end to the other. Bullet quality immediately improved. Anyone else experience this?