I’m attempting to replicate Underwood Xtreme Defender .38 special but I do not have load data so I am having to guess.

I have loaded 100 grain Lehigh Defense Extreme Defense bullets in all my test rounds, just like the Underwood Extreme defender

My cartridge overall length is just over 1.5 with the bullet seated in the cannelure.

Brass and primers are Remington, I had to take down target rounds due to the primer shortage.

My test rounds are 7.8 grains of Ram Shot True Blue, 8.3 grains of the same powder, and 8.9 grains of the same powder.

The test revolver is a Model 10-6 with the factory 4.2 inch heavy barrel, mine dates to 1977-1978.

Are my test loads safe or is that too much pressure?