Cast bullets generally run a 1/1000th inch over the standard jacketed diameter. Even if the box says 115gr JHP .355", you may find the bullets are .356" or other dimension. Oftentimes they aren't exact as marked. Bullets marked .311" may be .310" etc.
Some casters may offer custom-sized bullets, so you may find bullets several thousandths over/under-size.
Incidentally, I heard that Mr. Carroll died of lead poisoning, but I can't swear to this (just hearsay...).
Loaded a test batch last night using Bullseye powder, CCI primers, and the 124gr Carroll bullets. Held OAL 1.100 +/- 0.003. Loaded 10 rounds of each charge at 0.2gr increments from 3.4 to 4.0gr. Bullseye metered very consistently out of a Lyman powder measure. Hoping to get out this week to test fire.
In the earlier days (that is, when Carroll was still operating), I often used their 225g LTC .45 bullet with good results.
These days, I think coated is the way to go, even though I haven't adopted this process with my own casting endeavors. To be honest, I haven't been doing much casting anymore, as I find Norm's product and pricing make it hard to justify lighting the Coleman Stove. There are plenty of sources for economical coated bullets these days. Yes, it's still a good skill to know, but it is rather labor intensive.