Well I've done something similar to that. After muzzleloading season I had left my gun loaded with 150gr. of T7 and a 270gr. powerbelt. Well I went out to the range a month later and forgot that it was already loaded and I loaded another 150gr. of powder and 270gr. powerbelt. Well needless to say the scope gave me a nice wakeup call, it also threw me off of the bench. As for the rifle went, it was still in good shape and still shoots great.