I don't know of anyone doing this, but I don't run the circles where I would meet them either.

What I have been kicking around in the back of me head for about a year now is converting a Biakal 12 gage coach gun to fire high preformance Sabot slugs like the Remington or Hornady versions that use modern bullets in Sabots. The coach gun I have has been and still is heavily used for cowboy shooting and in another year or so of steady abuse will go down to to the flats. Rather than put a $300 gun back on face as a cowboy gun I've been thinking about getting a set of 12 gage rifled barrles and re-barrel/re-build it as a dedicated SXS deer rifle. I live in a slugs only area in Virginia, it would probably drive the DNR officer nuts but there's not much he could say, after all the ammo does say "12 Guage" on the head stamp.

As I have all the equipemnt to do this the cost is just materials and time.