I bought an NAA Black Widow with the conversion cylinder the other day. i shot both mag and lr through it. seems to be a good close range revolver (fist size offhand groups at 25 feet). i shot it at some thin junk sheet metal (probably a 16th to an 8th inch thick), the mag made a big dent, but so did the lr, and about the same from the aguila sss. none of them made it through. but the beretta 21a didn't make it through with federal bulk pack high velocity either. here are some pics for comparison.