I bought a fnp 40 cal for 390, been shot 1 time.. and it came with 5 clips and on them they say 40sw & 357 sig, so does this mean i can get a barrel for the fnp and switch it over to a 357 sig? And ive heard that the fnp's slider gets gouged by the slider release when shot, leaving a mark underneath were it says fnp does anyone know how to avoid this from happening? I couldnt turn it down because i thought it was a good deal, with original box and 5 clips..