An Imgur user and home reloader did some experimenting with LEGO heads as projectiles and had some positive results.
The bad news is that the heads actually cost more than actual copper-plated lead bullets, but they do fit a standard .40S&W case. However, you have to make sure they are of the solid design– some apparently have a hole that goes from top to bottom and won’t work.
As for loading data, he is using a Winchester small pistol primer, range-salvaged Blazer brass and no powder as each head weighs just a scant 8.6-grains. Not exactly SAAMI specs, but hey…
Shooting in his garage, he used what looks to be a Ruger semi-auto as a test pistol and fired into a dirty towel over an empty cardboard box from 10 feet away.
The LEGO head went thought the towel and the box and ricocheted off the door frame but was recovered. You can see the rifling and note that, while it did compress, it did not lose any weight.
So of course, there is more testing to be done.
We’ll keep you informed as this is a developing story and, as always, don’t try this at home due to possible barrel obstructions etc.
[ Imgur ]