TargetTalk

I would like to be able to add a magnifier lens to my 30mm match dot.
I only want to use it to test loads, not shoot it in matches.
Anyone know of such an animal?
Even a 2X would work.

You might try a camera supply catalog. Some of their pieces are designed to fit spotting scopes and other small lenses.

You could possibly achieve almost the same effect, by using a 2+ magnifying lens over your shooting eye.

Leapers, Mako, and others offer them.

If you are using it for a pistol, you might find they won't fit. I have one on a Ruger SR-22 but it is almost the size of a full scope. To test my 50yd loads I mounted a pistol scope with 3-9 power. It really helped reduce the human error factor and increased the accuracy of my testing.