Its not reliable to measure temperature of aluminum like that.
You'll need to make the surface emissivity higher, normally put black tape or similar, but the high temp will melt it. Also the IR gun needs to be much closer. If you look at the instructions of the gun it will give you a ratio or angle.
https://www.fluke.com/en-us/learn/blog/temperature/how-to-get-great-results-with-an-infrared-thermometer
Thanks, I did test much closer and at different angles, didn’t make much difference (and keeping it in any one place, was jumping around all over the place). I took the pics further away so I could get the laser dot in the pic.
Just read the link, very useful info.
I think Bassman59’s idea is excellent and will give it a go later today.