I still don't believe that a primer alone would drive the bullet to the muzzle.
Especially in a revolver, where the cylinder/forcing cone gap would bleed off some of the already-low pressure. Usually those end up locking the cylinder, with the bullet halfway through the gap.
Primer pockets get my attention, especially when I noticed that I was creating my own potential problem. For a long time, I would decap and resize rounds, then tumble them one last time for a final finish before priming and charging the cases. What I had overlooked was the residual corn cob media lodged squarely in the flash hole or primer pocket, before the cases got primed. I never had any hangfires or misfires, and I attribute that to the primer blowing the contaminant out of the way before lighting off the powder charge. I caught it because I was doing a stretch ring test with one .30-06 case, and a piece of corn cob media fell out of the supposedly clean and empty case. Further investigation by holding the deprimed cases up to a light revealed several blocked flash holes.
Needless to say, I've changed my techniques.
I have, however, witnessed a fizz-bang (more of a fizz-pop) on two separate occasions. One was a beautiful Colt-Sauer in .458 Win Mag, that made the goofiest sizzling sound as the bullet went downrange, leaving the barrel heavily fouled with the unburnt extruded powder granules of IMR4198. We surmised that contaminated primers were the culprit, and the sizzling sound was the compressed powder charge wad burning as it stuck to the base of the bullet on the way downrange. The unburnt IMR4198 looked golden in color, probably because the deterrent coating had been flashed off?
The second fizzle I witnessed was with the owner of a Rolling Block in .45-70, again using IMR4198. (No connection to the Colt-Sauer incident) This time the 405gr cast bullet went about 6 inches up the barrel before stopping, with a big wad of unburnt IMR4198 stuck to the base of the bullet. Again, once the bullet and powder wad were tapped back out of the breech, the plug of extruded powder grains had a golden color. Odd, and we chalked it up to weak ignition from a primer with perhaps less priming compound than normal.