Staff Writer (Updated: 7/29/2015):
The resulting B4 proved of high quality and durability and was distinct from other combat shotguns in that it operated from a detachable box magazine instead of a tubular magazine. Additionally, the B4 could be operated as a self-loading weapon or manually using the pump slide. The semi-automatic action was to provide a higher "second hit" probability by not having the operator pump the slide to introduce the follow-up round, thus potentially losing track of his target (if only for a second or two). The shotgun also featured an integrated carrying handle, folding stock and a high-quality steel barrel with an overall anti-glare finish. Ammunition types were all conventional and the weapon could fire from a 3-, 5- or 8-round curved detachable box magazine.
The series, along with its semi-automatic action, were banned from import in the United States, along with several other potential box-fed shotgun systems on the civilian market (including the Italian Beretta M3P and French SPAS-15) - courtesy of the Assault Weapons Ban Act beginning in 1994. The B4 also appeared in a pump-action only model designated as the B4/B. The B4/B visually retained the stock and body of the B4 with some slight alterations to the pump slide and forward section.