XLC is Barnes' proprietary process similar to moly which claims to have the same benefits -- decreased friction (thus slower heat build-up) longer accuracy life
for a barrel and less frequent cleaning intervals.
That all translates into increased dimensional stability and longer accuracy life
They reduce friction, increase barrel and accuracy life
, reduce fouling, and make a bore easier to clean when it does need it - which ain't often
A bore guide is cheap insurance that a barrel's accuracy life
isn't cut short by rod abrasion in the throat area.
Basically what MD coating offers is a 3 percent or more increase in velocity because of less bore friction, greatly increased accuracy life
for barrels, more uniform velocities, an 8 to 10 percent gain in accuracy, and easier cleaning because fouling is greatly reduced.