Kywoodwkr, I have tried several of the knock off brands with no success, the ruger brand so far have been the only ones to work in my series 180. I have one Ruger 30 round that works flawless. The best price I have seen on the Ruger brand is at Cheaper Than Dirt$25.00. When they post them they sell out in short order. I have been trying to catch them for awhile now and everytime I call they have sold out. If you can find them for $35.00 buy them, I have seen them as high as $70.00 for the 30 rounders. the 20 rounds sell for $35.00-$50.00.
If you do not want to pay $35.00 pass the info on to me I will buy a couple at that price.
arky65