i can assure the 9 cars wont be done in a day. at that even a week. i prefer to take my time with things make it count if you know what i mean. as for arms falling off thats already happened plenty of times. im a frequent range goer. about 4 times a week average of 6000 rounds a month. my arms and hands are permantly numb. lol. im sure ill be alright with it. im glad to hear it a good tool. but a tool is nothing great unless the operator knows what he is doing with it lol.