I picked up a CZ 452 in 17 HM2 and am curious about how often you clean the bore on it. I have a 452 in 22 lr that may have had the bore cleaned three times in the 3 year's I've had it. Unless I've had a 22 out in bad weather I do not clean the bore as I do with my centerfires. With the HM2 velocity's and jacketed bullets I'm wondering about this. Thanks in advance.