He might mean 10 in the fixed mag and one in the chamber?
My room mate made a set of 3" steel plates and we set it up at 100 yards. For the record, these plates fell off of the swinging platform (looked ROUGHLYlike this originally...
but they were KNOCKED OFF of the target stand by 5.56 and 7.62. Just a word to the wise, use 1/2 to 3/4 steel
(the missing paint areas with no hole are .22lr, due to GSG5 savageness!!!!!!!)
A lot of those holes are 5.56 believe it or not. He used 1/4" steel, and 5.56 went through it like butter. Kind of gives me more respect for the round, TBH. The 7.62, however, made indentations along with a hole, and the weighted targets would spin for a few seconds as opposed to 5.56 swinging back and forth. Gotta love energy and foot pounds. CHEEEAHHHH.
Anyways, I was consistently spinning targets at 100 yards using iron sights. The stock made a huge clear-cut advantage over the original, and I recommend it to SKS patrons who don't mind changing the look of their rifle. Timbersmith's don't require permanent modification to your existing stock, either. Still have the original.
At 50 yards, I blew out the 10 ring with ease. No need to church it up, but this dog will hunt.