I'll join in on this as this was on one of the other boards earlier this week.
Moly will ruin your barrel, no matter how careful you are.
Talk to any quality barrel maker ie: Hart, Shilen, Rock Creek as well as others. Ask them why they will void your warranty if you use moly-coated bullets? Then ask Speedy Gonzales what he sees when he looks into your barrel with his $3000.00 bore scope with only 25 rounds of moly coated bullets through it? They will all tell you the same thing.
I realize many will disagree and they love this stuff, but the fact of the matter is, you cannot moly coat your entire barrel with bullets a lone. Be objective and look at this logically.
The bullet contact surface in the barrel is only so big. It's like trying to wax your entire car with just a tinny dab of wax and starting over at the exact same place each time you apply more wax to applicator. You just can't cover the entire car, but you get a nice wax build up at the starting point. Same thing with trying to moly coat your barrel with moly bullets. You get a nice moly build up right in the throat area and not much moly beyond that.
When your round goes off, moly comes off the contact surface of the bullet in the throat area of the rifle and is bonded to the barrel do to the excessive heat and pressure. Were not talking coated or adhered to, we're talking bonded to. With this, carbon is formed and some of the jacket coating comes off the bullet. Follow this up with another round and you've now embedded carbon and the copper jacket between layers of bonded moly. This is the beginning of the black moly ring, which ruins countless barrels and is so hard; it can hardly be scraped off with a screwdrivers corner edge. This is what happened to a brand new Shilen SS select match barrel I had to have replaced with less than 400 rounds through it.
For those of you who think you'll clean moly out of your barrel with a solvent, you're kidding yourself. Name one gun cleaning solvent that will dissolve Molybdenum Disulfide ( MoS2 ). You're not going to find one. Yes, I'm sure some of these cleaning products will remove loose moly, but not moly that has been bonded to the inside of the barrel. And I really don't think you can brush it out when you clean your rifle with a bronze brush. I doubt you'd like the results after looking through a bore scope. Doug Shilen at Shilen barrels could barely scrape the moly out with the sharp edge of a screwdriver on the barrel I ruined. I could have scrubbed with a bronze brush for days on end and I wouldn't have touched it.
I won't ever use the stuff again. But, I'm sure this debate will continue for another 10 years or so.
[ 02-26-2004: Message edited by: Jeff In TX ]