Well you have no argument from me about a few things. First, Paradox guns exist in more than one form firing more than one type of ammo. Some are more like shotguns firing bullets, others are more like rifles firing shot, and some are a pretty even mix. It makes it all interesting and fun. Second, Paradox guns that fired bullets of more than one component were able to reach velocities that made them useful for longer distances. Third, if Mr Seyfreid shot an elk at 250yds with a capped Explora bullet then the gun and cartridge did the job.

However, regarding stability of bullets slowing to the speed of sound, the phenomenon is well documented.

The Transonic Problem

Ballistic Coefficient Variations with Muzzle Velocity near the Speed of Sound

Bullet Stability

Supersonic loads, regardless of alloy do not group as well at 100 yards as slower loads, because they are subjected to transonic buffeting as projectile velocity decays below the speed of sound.

In the 1905 report you cite above it is very simple to see that they are speaking of a bullet that was never supersonic. The Magnum Paradox used charges of 4.5 to 5 drams and the article clearly states that the bullet "started out at a low velocity .22 rimfire speed". Slow moving lead bullets can be extremely accurate, even at long range. No news here.

Regarding "Ross Seyfied wrote in the Spring 2006 DGJ of a killing shot on an elk at 250yds using a 1250fps Explora capped bullet": Surely that bullet had become subsonic and accuracy must have been adversely affected, but an elk is a big animal and apparently things worked out right.

AND... I'd love to have an old Expora or Faunetta.