TargetTalk

For 148gr 38 cal wadcutters do the bevel base or flat base versions work better? I cast my own bullets from straight wheelweight so the hollow base version is pretty much out of the question... haven't found the mold. The bevel base should be slightly easier to get started in the case but that's the only real advantage that I can think of right offhand. Thinking possibly the flat base version might give somewhat smaller groups.

In my experience bevel base work fine, flat base may be a bit more prone to damage, not sure really.

Is 100% wheelweight metal not a bit too hard? I didn't find it filled all that well either. Not all wheelweights are wheelweight metal these days.

Provided the base of the mould casts cleanly and square, with a well shaped sprue cutter, then there will be no difference in accuracy.
Accuracy will depend on bearing surface, twist rate, size to suit barrel, lube, velocity and powder burn rate.
I shoot a 134 WC with a single lube groove, bevel base and wax based lube. This will shoot a 18mm group (outside to outside) at 25m.

wheelweight metal = the cheapest metal that will work in the casting machine!
I.e. it will vary (greatly) from one run to another, depending on what the manufacturer has available to use at the time.

Bebloomster,

I believe your thinking is correct in every detail. I also think that swaged bullets will generally be more accurate. You might want to take that up.