I've been to four formal courses for training now. Wolf was used in three of those four courses and resulted in stoppages in two of those four courses. First course used lacquered Wolf (no stoppages). Second two courses used polymer Wolf. Don't know the make of the first rifle; but the second rifle was a factory Bushmaster M4 clone.
In the first three courses, I didn't really pay much attention beyond noting who was using what. By the last course, I had already become curious about the frequent report of stoppages with Wolf and had done some tests of my own (lacquer doesn't melt off by the way) that seemed inconclusive so I spent some time with the Bushmaster trying to figure out why it wasn't working with the Wolf. I determined a couple of things.
1. The Bushmaster ran fine with every kind of brass ammo out there. Zero stoppages. Call me crazy; but if it works with every other kind of ammo and doesn't work with a particular type, I tend to assume the ammo is at fault and not the rifle.
2. The Bushmaster would run fine with Wolf as long as it didn't get hot. When we started doing relays where the rifles were getting toasty warm, stuck cases started appearing at relatively low round counts. This reminded me that the other course where I saw Wolf cause stoppages was also a high-round count course (about 800 in a day).
3. Fouling was nothing short of incredible. When we opened the rifle to check out the stuck case, there were chunks of hard, baked-on carbon the size of bolt lugs falling out. I thought he had broken a lug or some other part because I had never seen carbon that big come out of a rifle before. I also know that the rifle was clean as I had cleaned it with him the day before and cleaned it with him not 100 rounds earlier when the stuck cases started up again.
4. Same Bushmaster that wouldn't shoot Wolf shot Hornady steel cased training ammo with no problems.
On another note, my friend has an Armalite that has less than ten stoppages over 7k+ rounds with brass ammo. It fired the same batch of Wolf just fine; but choked on every single round of the Hornady. Go figure. I still don't know why Wolf tends to cause problems; but it is clear to me that steel cases, straight-walled chambers and direct impingement is not an ideal combination.
Advice-wise: If you are going to use Wolf, you need to test it before you bring it and use it the way you will use it in the course (get the rifle hot, let it sit, get it hot again). While training for malfunctions doesn't hurt, you don't get much training value out of the Wolf as the typical malfunction is a stuck case that requires tools to remove. In every case I've seen where Wolf caused a stoppage, it wasn't anything you could clear easily or quickly and training for everyone stopped while the instructor tried to clear the one rifle.
