Abstract: A muzzle loading bullet gas check has external recess and ridge system, and/or an internal locking ridge system. The preferred gas check has an opening or recess on its front end for receiving and frictionally engaging a rearwardly extending post of the bullet, the opening also preferably including an internal radial ridge for gripping the post and/or locking with an indent on the post. The barrel-interacting part of the gas check has one or more external recesses and adjacent radial ridges/edges protruding relative to the recesses, which serves to reduce the total surface area of the gas check contacting the bore. The recesses do not touch the bore of the firearm, resulting in less friction and easier loading, while the outer ends/surfaces of the ridges/edges do touch the bore to retain the bullet in the bore during handling and hunting and to effectively capture gasses after the firing explosion.

Abstract: The present invention is a saboted projectile with external ridges and/or an internal locking edge for muzzleloading firearms. Also, the present invention is a sabot with the ridges and/or locking edge for receiving a muzzleloading projectile. The sabot has a forward part and a rearward part. The forward part has a plurality of axial panel sections separated by narrow, axial slots. The panels have radial ridges on their outside, or external surfaces. Also, the panels have a radial ridge on their inside, or internal surfaces. The external radial ridges assist in convenient loading of the muzzleloading projectile, while still providing enough contact with the inside of rifle barrel to capture exploding gases and prevent blow-by. The internal radial ridge assists in securing the sabot to the bullet, especially when the bullet has been provided with a cooperating radial indent, cannelure or retaining ring.