I bought 8 lbs of commercial #5 from the internet and then could not find any data for it for 38 special anywhere. One post said to use Accurate #5 data. I wasn't about to trust that so I called the manufacturer Rio. Their customer service rep refused to give me any data. He said that the powder was sold to a buyer who misrepresented what the powder was going to be used for and that the sale of the powder is illegal. It sounds more like a civil matter to me The rep did mention that they were going to retail the powder at the beginning of the year so they must have the data. I mentioned that in all probability if someone is injured because of faulty data and the manufacturer of the powder has withheld data for powder that they sold they will undoubtedly find themselves one of the deep pocket defendants in a law suit. (In my layman opinion.) You know how lawyers are. They sue everybody. He couldn't really get past the fact that the buyer said one thing and then retailed the powder. I called the company I bought the powder from. The rep was cooperative but I am not sure what he told me is reliable. He told me that the two # 5's are similar but that powders with similar burn rates still can have different characteristics. He said the powder data would be close to Unique and Universal and suggested using Universal Data and lowering the starting load by 15%. I am not in dire need of the powder. I bought a couple of pounds of Accurate # 5 at a gun show after I bought the Rio powder. I also have some WSF, and Promo. I think I will wait until someone more experienced than I works up the 38 special loads and publishes the data or the manufacturer starts retailing it and is forthcoming with data.