In many of our ammo tests, you will see the use of wet phone books as a substitute for ordinance gelatin. Granted, the phone book is not a scientifically accepted test medium, but it does yield pretty consistent results with either solid or expanding projectiles. One of these wet phone books generally translates into 8”-10” of penetration in calibrated ordinance gelatin when comparing the same load from the same gun. This is a bit less than the FBI’s 12” minimum standard. So, if a round fails to penetrate one of these books, it certainly fails the FBI standards.
To keep things in proper perspective though, lets keep in mind that the FBI standard was in part developed to weed out cartridges that failed to function properly after passing through intermediate barriers such as auto safety glass, and car doors. Therefore, if you are an LEO these standards are no less than a doctrine to live by. For civilian defensive use though, a round that fails the FBI test is not necessarily a useless defensive round. Keep in mind that civilians won’t likely be blasting bad guys through car doors with much regularity. Even if your particular ammo only delivers 10″ of penetration in ballistic gel, that’s still a nasty 10″ puncture wound. And, if delivered to the right spot, it will do the job.
Unfortunately, real ordinance gelatin requires you to keep it refrigerated until minutes before testing. Since the nearest testing site is about 40 miles away from my fridge, real gelatin will just have to wait until I buy that dream ranch in Montana. But don’t feel too bad about it, these book tests give us a good estimate on how ammo will perform in wet mass. And, they have some nice pictures of ambulance-chasing attorneys to inspire better aim.