Turret Press Index Problem
Three Hole
The most common cause for the Three hole Turret press to fail to index is an over tight clamp screw. This collapses the clamp (the clamp is the two die cast parts that fit around the end of the ram) so that the outside diameter of the hex ratchet drags on the inside diameter of the clamp. The fix is to loosen the clamp screw until the clamp halves are just together. Attempt to index the press which will probably fail at this point, tighten the clamp slightly about 1/8 turn and try again. The idea is to sneak up on this from the loose side as opposed to try and loosen to the proper point.
Four Hole
Four hole Turret presses that have index problems are handled differently. Determine if the turret hole is not coming far enough around to snap into position or if it going too far after fitting into position.
If the turret is not coming far enough around, remove the turret and secure the 1/4" action rod with a 1/4" wrench. With a pair of pliers, turn the nut on the top of the action rod very slightly counter-clockwise. Put the turret back and try it. Repeat this step until the turret snaps into position correctly. If your turret is going too far around, follow the same steps except that the nut on the top of the action rod would be moved very slightly clockwise. Further adjustments will not be necessary and the rod can be repeatedly removed and placed back into the clamp with no ill effect.
With both style presses, lubricate the outside diameter of the Turret with 30 wt. motor oil, or something similar.