Most likey it's a 1:10 which is optimal for most 30 caliber bullets 0f 150 grains. You can figure the rate youself quiet easily with a cleaning rod and a jag/patch. Mark a place on the rod about a foot up, insert the jag and see how far it travels down the barrel until the mark is oriented back to same position. Measure the distance the rod is inserted and that's your answer.