Tossing Rounds down range is easier than ever with this Korean Beta Mag knock off from KCI. I found my KCI magazine to run very well with standard brass cased 55 grain ammo. However, running 62g or larger ammo, I found that the dual drum appears not have enough internal space to accommodate the longer round of the heavier bullets. The longer rounds tend to rub the front of the magazine and cause the magazine to jam. All in all, if you are looking for a drum magazine and do not have the cash to drop on the C-Mag. The KCI might be a nice option at about 1/3 the price tag.