I guess what I was trying to say is that based on my personal experience; lead slugs foul a rifled barrel in a short period of time compared to that of a saboted slug. That is just my opinion, and it along with $1 will get you a cup of coffee at most places.
However, I would also point to the book "Shotgunning for Deer" written by the worlds leading slug gun expert, Dave Henderson, (
www.hendersonoutdoors.com), Dave says " ...full bore lead slugs actually skid in a fully rifled barrel and will leave copious amount of lead fouling in the grooves in a very short period of time."
What that means in general terms is that the full bore lead slug isn't spinning its way down the barrel following the contour of the grooves; it is pushing its way past some grooves, shaving off the soft lead, and thus fouling your barrel much faster than saboted slugs. I've seen rifled slug barrels that look more like a smooth bore after 50 shots from the bench, using full bore lead slugs.
Can you shoot full bore lead slugs in a rifled barrel? Yes Sir.
Will the combo be accurate and provide sufficient energy to kill deer at reasonable distances? Yes Sir.
Is this combo what any recognized gun expert would recommend? Nope!