All of the Marlin Cowboy models have Ballard rifling, not the micro-groove. I shoot a Marlin Cowboy in .45 , and it's an excellent rifle. The .357, like most .357 lever guns, are sensitive to overall cartridge length, which can lead to problems if you want to shoot .38 ammo. I paid $460 for mine 3 years ago, so $490 isn't too bad. If you decide on a .357, find one quick, ' cause Marlin just did a run of these, and they are being snatched up fast, since most distributors had been out for awhile.