As some have stated, the move to CNC cut cavities is a watershed moment. Molds that were cut with cherries (old school) are suspect but the new molds if done diligently are going to not vary enough to amount to a hill of beans.
That said, a casters MO of how they operate their molds also has a great effect on how the product (castings) turn out. An average person will have greater variability in technique as the cavity count goes up.
More attention to detail and likely a mold guide under a bottom pour lead pot will be required because those multi cavity molds with a load of lead weigh more, Ie you get worn out faster.
As to rifle’s, caliber enters into the equation.
My best cast rifle story begins with a .338-06. If it had been even larger bore it would have been even better. As the bore gets smaller, the margin for casting error gets smaller.
Three44s