Solid Fuel Thermal Target: Bolt It Behind Your Own AR500 Steel

The solid fuel thermal target is a steel firebox that bolts behind an AR500 silhouette you already own and heats the plate until it reads as a warm body through a thermal scope. It attaches through the square holes most AR500 targets already have, with longer bolts, and nothing is welded to your steel. It burns briquettes, lights the way a grill lights, and the production unit lets you set how hard it burns.

https://www.youtube.com/watch?v=u9xZC5uGIW0

Watch: This Target Was Made for Thermal Scopes! (6:09) on YouTube. This was the last of the range trips for this design: the lighting, the strike-face readings, and the thermal view next to a person for scale.

Why bare steel is a problem for a thermal optic

Steel sits at the temperature of the air around it. By late night it is as cold as the berm, and in the middle of a hot day it is as warm as everything else, so through a thermal optic it disappears into the background either way. A heated plate stands out from the ground behind it at any hour.

The firebox sits behind the plate on longer bolts through the plate's own square holes. Nothing is welded to the steel.

What you need

• An AR500 silhouette big enough to cover the firebox, with the usual square mounting holes. Those holes, about three quarters of an inch, are the whole attachment.

• The firebox and its longer bolts. The box hangs on the bolts behind the plate.

• A bag of briquettes and a way to light them. Lighter fluid was used in the video.

• A thermal optic, or a phone thermal camera, to check the read from the line.

Does the heat soften the steel?

No. The unit is built and tested so the plate stays well below the temperature at which AR500 starts to lose its hardness. The plate gets warm enough to glow in a thermal optic and no warmer, so it keeps taking rounds the way it did before.

Lighting it, and what the plate reads

1. Take the side panel off. It is held by one wing nut and a wing bolt and slips out of a slot.

2. Lay the unit over, put the briquettes in, and light them as you would a grill.

3. Wait. Nine minutes after lighting, the strike face in the video read 59.6 C from a starting 19.9 C.

4. When the fuel shows the grey layer of a good burn, fit the side panel back on and stand the target up.

5. Walk back and check it through the optic. The smoke clears once the burn settles.

Side panel off, briquettes in, lit the way you light any grill. The strike face read 19.9 C before lighting.

Smoke while the fuel catches. It clears once the burn settles.

What it looks like through the scope

The silhouette reads as a bright body against a cold background, and a person standing beside it reads about the same. That is the point: the target gives the scope the same signature the scope was bought to find.

Through the thermal: the plate reads as a body, and the person beside it is the comparison.

What changed between the prototypes and the one you get

The unit in the video is the test unit, unpainted and weathered from the trips before it. Earlier versions would not hold a solid burn; this one does, and the production unit also lets the burn rate be set. Otherwise what is on camera is what ships.

For the electric version, which heats on a battery with no fuel, see the Thermal Optic Targets page. The solid fuel firebox is the one in this video; ask for it by name when you get in touch, and tell us the size of the steel it has to fit.