The term "wax slug" is somewhat confusing and I am not a fan of the name. These are homemade, user-modified, or do-it-yourself shot gun rounds where inexpensive, low-power birdshot shells are used. The entire top of the shell is cut off, and the bird shot is mixed with hot, liquified wax. The mixture is then poured back into the shot gun shell which acts as its own mold. The purpose of the wax is to simply hold the lead shot together so all the pellets impact together as a unified force.
The wax is "just" strong enough to accomplish this but weak enough to allow the pellets to break back apart upon impact with even light objects.
The first round of testing provided some very unexpected results. The rounds were very "frangible" but managed to penetrate a 4" book, 2x4's, computer hard drives, etc. before the rounds broke apart.
Round 2 Tests
We are planning a second test of the 12 ga. wax slugs as soon as possible. I have made a small modification to the process which still keeps things simple but should help keep the slugs flying more true in flight and not tumbling. Though these rounds are relegated to somewhat close-range use (less than 100 yards), the rounds are still very unique and have uses unlike any other round.
We will test the possible use as a "home defense" round. Though some shooters may balk at using something "homemade" to protect their life, we feel the modification has no effect on the reliability of the round in any way. This role may be a perfect application for these rounds.
Simulated drywall shot
Shooting 1/8" thick mild steel
Wet toilet paper roll (simulate section of leg)
Long-range stability (approx. 100 yards)
We have tried three different brands of 12 ga. sport loads for these tests
Remington Sport Loads (#7½)
Federal Field and Target (#7½)
Winchester Super X Game load (#8)
The Federal shells have a 2-piece wad and are the shells we'll be focusing more on. The
shot-cup has a natural skirt on it which may also help stablize the shell and may stay attached to the wax slug for a greater distance and less drag.