Painkillers: There could be a potential sweep problem from a cross draw holster, if the shooter starts standing square to the target. With the holstered revolver facing along, or even pointing slightly behind the firing line(Depends on holster position on belt).
*Not so much, if the shooter starts facing at an angle away from the target ( For a right handed shooter, with the right foot placed about a half step back. Shooter's body aligns approximately 30-40 degrees away from firing line) The holstered revolver points down range. The 170-degree safety rule** is now in force. No sweep. Vice versa, for lefties.
Or: Just before executing the draw, rotating the upper body away from the target. Some shooters may also step back and rotate the body...pretty much duplicating the half step back starting position. This is often called: The 'cross draw dance'. With the revolver also pointing down range, as it clears leather. Again, the 170-degree rule applied.
As for transferring a revolver from one hand to the other, that is only a matter of practice. Careful attention needs to be paid to timing and hand positions when executing the transfer, so it proceeds smoothly. Otherwise, the process is not difficult to master.
It's understandable that some ranges will have valid safety concerns. But, a demonstration of the two safe cross draw methods, might convince the folks in charge how little....if any....chance there will be of a sweep occurring. When a cross draw is executed properly and safely.
Al
ps: I've seen the North Border draw Vicious describes, on many occasions. When done properly, it is fast, smooth and very efficient.
*Try this...will illustrate start position. Start, standing facing forward, both feet about a shoulder width apart and aligned square to the target. Now, take a half step back....either left or right foot. Note, how the upper body and pelvis will naturally want to rotate in the direction of the rear foot. If your holstered revolver started out pointing pretty much parallel to the firing line, where does it point, now?
** 170 Rule: When engaged(staged, or in shooter's hands), firearms may not point at an angle greater than 170 degrees, from the firing line(Firing line at 180-degrees). This provides a margin of safety for anyone on or behind the firing line. This rule applies at all times.
For detailed infrmation on safety procedures, be sure to access the SASS Shooters Handbook. Page 13 notes the '170 Rule'.