Since most reloaders don't load heavier bullets than standard factory loads, I've found it a good general rule to get the heaviest bullets available. This because their longer bearing provides the best accuracy. Twist rate isn't a concern in most cases because bullet weight is light enough in factory ammo to shoot in all guns. To eliminate jacket fouling, place a light smear of Tetra lube around each bullet right up close to the case neck. By light smear I mean, put a drop on your finger and use it on maybe three catridges. This works with all calibers I've tried from slow handgun up to the fastest rifle.
Due to most low cost commercially reloaded lead bullet ammo having bullets sized to nominal diameter, which is too small in a majority of guns, and being lubricated with inferior lube, I think one is wise to stick with jacketed, which aren't persnickity about diameter, rough bores etc, etc, like cast. I notice that the price is about the same with either type of bullet so why not get the tougher ones. Also of interest, all LOW COST lead bullet loads I've seen are poor game ammo, even for squirrels. A wide meplat is mandatory to make non expanding lead or jacketed kill cleanly and consistently. (JHP ammo gets a VERY wide meplat on impact, IF the bullets expand, which many don't if not loaded to full velocity.
Sorry pal, but the gun show chap had it backwards regarding twist. More twist is needed for heavier bullets. but as I said above, don't worry about that with nominal factory weight bullets. As a general rule, accuracy problems will be greatest with lighter bullets because their short bearing allows them to tip on takeoff, in chamber and throat, and nothing can straighten out a tipped bullet, whether it be jacketed or lead. It will fly to the target tipped, and tip worse the farther it flies.
