Just thought I'd toss this question out. My beloved Sierra-Pro has always been one of my go to guns, and a great hunting tool in the field. Lately, I've noticed that there's been a slight bit of buzz and the velocity has dropped off. Now I've probably put aboutclose to 10k rounds through her since I got it back from the Tuna, so my question is,...Can a Macarri spring weaken over an extended period of time?? I don't think it's broken, but just seems to lack the punch it had before. For the most part, this rifle has been shot using Beeman Cro-Mags. Yesterday I shot some FTS's (shooting around the low to mid 700's)in it and noticed a slight bit of dieselling, but that cleared up in no time,....perhaps the seal may be worn out. Like I said, I've used this rifle ALOT, and thought I'd ask for some ops before I go tearing into it,...which I care not to do too often anyways. Tuning a fresh and raw springer is alot of fun,...but I hope to do the least bit of maintenance on my tuned rifle as I can get away with. Simply replaceing the spring would be ideal,...but if needed, I'd replace the seal as well. Just hate to "fix" what ain't broken!!!! LOL's tjk