My .504 cal M98 Elite Hunter came with a musket cap BP. A few years back I had to purchase a stronger spring from Doc due to misfires. It is the only ML that I own with a musket BP. I am not a fan of this plug and was considering swapping out one of my other no.11 BPs from one of my other White's. The no.11 is much easier to cap using my no.11 capper especially when scope is attached. I am not sure if there is a big difference especially since I use the hot RWS caps. Seems like the no.11 would be more rain proof for hunting as well. Also it is next to impossible capping the plug with a musket capper when scope is attached. It is too fat and bulky to get the under the scope to get the musket cap on. Question; Is there a major difference between the 2 plugs as far as ignition, performance or something I might be missing?