I did do the ramrod test. A half a dozen ups and downs and the average was a half turn in 26-27 inches. Given that would be a twist of 1:52-54, an odd result.I figured there was probably some slippage since pressure was being applied to the ramrod creating resistance and actual rotation was likely faster not slower. That's why I thought 1:48. I suppose if I had a hard object which would span groove to groove (maybe a dime?) I could bed that in a dowel and get a more precise reading.