Please post a link where it states Traditions now uses 4140 steel although thats nothing new. All ive seen is a generic chromoly reference on the Traditions website.
Knights have been made from Green Mountain 4140 and 416 for a really long time. I have no idea where you are getting the 1137 from. Ive called GM about this and was told its 4140. The old Knight manual that covers the Revolution only states rifle grade steel.
Currently the only 2 non stainless offerings even state its 4140
https://www.muzzleloaders.com/product-category/muzzleloaders/tk2000-shotgun-muzzleloader/https://www.muzzleloaders.com/product/vision-max-1-break-action-muzzleloader/4140 Alloy Hand Crafted Barrel
