Sealant in Military M118 Match Ammo

[Bart B.]

Just Like the Asphalt has nothing to do with it (bullet hold, pull force, etc) in Military ammo. The Asphalt is put in there so the ammo passes water / moister ingression specifications. That's the reason its there on Small Arms Ammunition.

Before bullets and sealant were put in military M118 match cases, case mouth and inside neck diameter is about .001" bigger than bullet diameter, no neck tension at all. Sealant is smeared in then bullets seated, then it glued bullets in place creating at least 20 pound extraction force. Take some apart then measure them. Or go to LCAAP then ask them.