Slugman.. in responce to your quote reference the CVA Mountain Stalker and Bobcat..
Just dont put a 150 grain charge in those "spanish" barrels ..........be careful.
I am sure that if he read the manual they noted that this rifle is not meant for 150 grains of powder. I believe it says the max powder charge is 100 grains of loose powder. I would have to check my own CVA Mountain Stalker manual again to double check the powder amounts.
Since my Mountain Stalker shoots best with 85 grains of powder and a patched roundball getting close to your 150 grain warning amount will not be a problem. My Mountain Stalker is doing well so far, three shots three deer in the hunting field.
You mentioned you were getting a Lyman's Great Plain Rifle I believe it was... How is that rifle shooting for you? Any problems with it? They normally are great shooters....