Pulled the hammer from the bolt of my AH420 today to clean the powder residue from behind it. Noticed the spring had a fairly hvy grease on it. What exactly is the purpose of this grease and what type. The grease was on the spring itself, not the bolt threads that hold it in place. Has anyone tried Precision Rifle's breach plug and BH209 in this gun. The open syle plug on the gun has a lot of fouling that escapes and if I can cut back on this, cleaning would be much easier.