I bought a Mil Pro 145 gen 3 today stripped it cleaned and lubed it but have not fired it yet. I don't know if I just lack arm or hand stregnth but when I have racked it to put a round in the chamber I can't pull it back with just the fingers on my left hand. I have to go over the top with my entire left hand to get the slide back. Have tried it with both magazines. Has anyone else had this problem?