I recieved some new vent liners from Savage this week. I had some of the older version with 3 holes. They traded them for the new ones. I've Been using the RW vent liners(they work great). The new ones from Savage have a counter sunk,or deeply concave area on the end. What's up with this? Have any of you tried these? I read somewhere that they thought these were supposed to help keep the carbon from building up so fast in the breech plug,is this true? Ron S