M*CARBO Brotherhood

Dimming Laser Cartridges

I purchased 3 laser cartridges for dry fire practice a while ago. The three I have are .223, 9mm, and .380. I use the 9mm daily with my M-series Keltec Sub2000 gen2 causing a dimple in the rubber primer where the firing pin makes contact. After a while, I noticed the laser cartridge flash on that cartridge became less brilliant. I also discovered all 3 of the end caps are interchangeable with all 3 of the cartridges in my collection even though one laser cartridge I purchased was a different manufacture than the other two. When I replaced the end cap of the 9mm with a seldom used end cap, the brilliance of the flash was just like it was originally. To restore the original laser pulse brilliance dot/flash, I can purchase a new endcap, or…see question below.

My question: Would anyone know of a compound I might want to try to apply to the rubber bottom of the end cap primer that will duplicate and fill in the firing pin dimple on the rubber primer, restoring the integrity of the rubber bottom where the firing pin makes contact? thanks