I just bought a mossberg 535 12 ga. The barrel is smooth and unchoked. it came with a turkey choke. the guy at The MOUNTAIN store said that i could buy a improved choke so i could shot slugs. He also stated that i could by a slug choke. anyone heard of the that type of choke, would i be better just buying a rifled barrel or just adding the improved choke and saving some $$$? does it really matter? oh and if you own one of this guns what do you think about it, any problems.