Doc, give those reloads of yours a test run using CCI BR2 primers with a newspaper wad over the primer hole. This recipe may equal or better the 1 1/2 group. BTW, this size group @ 100yds (hope it was with iron sights) ... is not shabby!
OK, beagling a mold: Some molds drop a bullet depending on the alloy ratio of choice that has a base diameter less than desired ... ie, one wants a 380 base bullet from a 378 mold. So, go to the hardware store and buy a roll of aluminum tape used in the HVAC industry. Then to the mold half that does not have the mold pins, cut a 1/8" strip of the tape and apply it vertically to the mold half (close to the cavity). Squeeze the mold halves tightly to press the tape securely on the mold half.
When you cast using the tape ... you will increase the size of the bullet driving band and base .
I have a Lee 457-500-3R mold that now drops 460 base bullets and the Lyman 378674 from 379 to 380/381. Then I lube/size the bullets with custom size H&I dies or pan lube them without running them through the lube/sizer