Years ago I had a 12ga. with PG stock and plain buttpad (ouch) and wanted to sling it. I also thought a slip-on recoil pad and/or a buttstock shell carrier might be in order, and a stud at the point CW mentioned (about the most common position) would be in the way. Now, I consider a hunting gun will mostly be carried in hand, but once youve bagged you game or are hauling stuff to the Jeep (for CW) a sling can be, well...handi.
One solution would have been to get the slip-on pad on and locate the stud just forward of it and the shell carrier maybe would fit forward? No....it needed to be back over the pad a bit. If the stock had a pad installed the stud could be just aft of the shell carrier? Maybe....but a small hole through the bottom seam for the stud would help hold the carrier in place.
I ended up putting the stud right in the bottom of the pistol grip. The sling had to be short, but worked fine for the occassional carry and the stud was really out of the way most of the time. Yes, the gun wants to shift a bit more toward 'horizontal', but not that big a deal.