I hate to say but you're confusing the devil out me.
If your purpose is a mid-range wadcutter load for NRA Conventional Pistol
competition, the 148 grain Hollow Base Wadcutter bullet is a viable choice.
It is one widely used by bullseye shooters and has a history of use going
back many years. These loads are loaded to be mild: 1) to prevent
deformation of the bullet by "over-expansion" causing un-due leading of the
gun and poor accuracy and 2) to allow easy recoil recovery for the sustained
fire (timed and rapid fire) stages of the match.
Typically this is a .38 Special load, but it should work very well in a
revolver chambered for .357 Magnum. Loaded in either .38 Special or .357
Magnum cases. A Model 686 revolver should have no problem handling the
load. There are some (as Magnum alludes) who are concerned about
"flash-over" or odd pressure responses when a primer flash fires "over" a
light powder charge rather than "into" it. If that is a concern, Dacron
pillow stuffing or Kapok (available at craft or sewing notion stores) can be
used as a filler in the cases to hold the powder against the primer. There
is also a commercial product named "Pufflon" for the same purpose. See:
http://www.pufflon.com/
Even though I'm not a world beater, I've used HBWC bullets in .38 Special
revolver for both NRA Conventional Pistol and Police Pistol Combat matches
at 50 yards and 25 yards. With good results.
But, if your purpose is to develop a general plinking or light game load for
..357 magnum. Choose another bullet! The 148 gr. double ended wadcutter
(dewc) can be pushed along at 1000 fps or slightly more without causing too
much leading. The broad meplat on this bullet does a fair amount of damage
on thin-skinned game and adds a bit of "smack" for use against things like
bowling pins and steel plates. Refer to standard reloading manuals for
recommended loads.