i bought a used glock 27 and it is well used and worn in places like the barrel, slide is scratched up and dull, trigger is a tad loose i think, and the recoil spring is very worn. if i sent it in to glock would they replace anything like the slide or recoil spring or anything? do they do this for free minus shipping both ways? just wondering if anyone has any experience with this type of thing. can i also send in my magazines?