New to hand guns, I recently purchased a full size mp .40 with 4.25 inch barrel...my qestion is, can I just buy the slide with the c.o.r.e. attachment instead of buying a whole new handgun. I would really like to put the optics on the gun, which is only used for home defense and target shooting. I would really like to start into competition shooting after I get some practice with the new mp.40. I am and have been an avid hunter, shotgun in Ohio, for most of my life. I am new to handguns, but have a good idea what I am looking for. Any ideas or info would be appreciated.