Just saw your post tonight, so I couldn't be of any help. But IMHO, helical won't affect elevation at normal indoor ranges (i.e. 20yrds, 18m). Helical/Offset will stabilize the arrow faster and could slow it down somewhat at longer ranges (i.e. 45+yrds). As to weight variation in arrows, studies have shown that up to 100gr differences won't have as much effect at shorter ranges as will arrow straightness.

Jack