are at times hard to work with becuase of the shollow narow lands the bullet if pushed to fast and is of a soft alloy it will stip out. Thus cuasing leading and inacurracy. Push them slow and they seem to work fine.
Billy in fairness, can't the same be said of any barrel? Plenty of 6 grooves do exactly the same..
Ya see, I've got enough experience with cast barrels to say the MICRO is definitely one of the BEST cast barrels. Why? Those 12 grooves of modern day configuration offer around 20-30% more driving side height for total land area. Micro's do tend to run largish, but the first rule in cast is using a bullet at least groove dia, preferrably something a couple thou over IF they'll chamber safely.
Truth be told-- you find just as many problems encountered by casters not paying attention to DE-tales per fit, encountering these problems in ALL types of barrels. Those not kowledgeable in cast basics tend to blame a barrel, a bullet style, the powder, the lube-- whatever. The old lame tale about micro's is about buried amongst knowledgable casters.