This is where we need JackFish, hey JackFish where are you! You have to watch the pressure ratings on these loads. The Garret loads are expressed in both CUP, and PSI, they are NOT interchangeable. JackFish always said to stay below the 40,000 CUP levels. Well loads in the 30,000 CUP range have plenty of gumption. The 405 Rem. factory loads will do for almost anything you'll come across. I would only shoot Garrets if I was Alaska bound and in Brown Bear country. I'm planning on loading for the 45/70, and will try to keep the loads at the low end of the modern lever action load range. Usually the trapdoor loads run up to 28,000CUP, the modern lever action loads run to 40,000CUP, and the modern rifle loads run up to 50,000CUP. I hope this helps.
Don