Coffinmaker vs. Martial Gun (Slug Shot)

[NandabaNaota]

Now, I've had my unlocked coffinmaker for awhile, but I always hear people talk about how Martial Gun works alot better because of TP bonus.

Now I've been trying to find out how much Racc Slug is at when you have 200 TP. Figuring that most COR melee for TP in merits, the +9 racc would only be helpful for Barrage if you /RNG. But how much does Martial outweigh Coffin in Racc on Slug? RNGs welcome to input too.

Thanks for helping.