Im having a 4bore or i should say 4 gauge english fowler with a 58"barrel barrel made muzzleloader. I need a load data for 5oz payload. I want to shoot around 1100fpst for turkeys a 13 dram load would be 375gr of bp. But i was told by a guy with a 4ga blunderbuss 130-150gr would give me 1100fps. It will have a 1.5"diameter barrel at breach.

It should look something like this perhaps longer

http://m.youtube.com/watch?v=5MHpLnTfD7M