Hello. Like some other folks I enjoy puttering about with expansion testing and so forth. It is true that soaked newsprint and water are not the "gold standard" in expansion media as is 10% ballistic gelatin, but neither are they so far off the charts as to be meaningless. I cannot afford the $90 for gelatin nor have the facilities to insure shooting it at a constant temperature for repeatable results.
I didn't use phone books, just plain ol' newsprint that was soaked 24 hours and allowed to drain for approximately 30 mins.
This is not a jacketed bullet, but a Rainier plated 124-gr. 9mm. As you know, plated are not as strong and easier to deform than jacketed. This one impacted the soaked newsprint at 1161 ft/sec. This bullet is more easily deformed than FMJ. It didn't expand or deform and neither has any FMJ ammo I've shot into the same medium.
These three Winchester 9mm 127-gr. +P+ bullets were all fired from a Browning Hi Power. The bottom left was fired into soaked newsprint. Bottom right was fired into water. Top was recovered from a deer. Not exactly the same, the results are similar.
Both 9mm bullets shown here were fired from a Browning Hi Power and are Hornady 124-gr. XTP's. They were handloaded to an average velocity of 1244 ft/sec. The one on the left was removed from a javelina. The one on the right was fired into wet newsprint. Soaked newsprint seems to provide some fairly decent results, but like any test medium, it's only one part of the equation and an "indicator". It does not show any tendencies for bullets to veer off path as does the 10% gelatin.
I'm not sure that the "wound channels" in wet newsprint mean anything as I've been able to compare them but with one animal killed with a load tested. The upper right "wound" is from RBCD and large but shallow. The others are fairly typical of several different 9mm JHP's.
This is the interior chest wall of the deer killed with the 127-gr. 9mm bullet shown above. You are looking at the wound track as it entered the body. Again, I've not really done enough of this to see how "true" it does or does not hold, but it doesn't appear much different in size than what was seen in the soaked newsprint...at least with that bullet in that one case. We'll see, but that sort of "testing" is not so easy to do at will. Soaked newsprint does underestimate penetration compared to the ballistic gelatin and I'd sure use the latter if I could afford it, but for now, the newsprint has the right price.
Best.