It should be fine, You just need to remember the GI method of charging and train for it. Palm up, cupped hand, thumb along side of hand, NOT WRAPPED AROUND CHARGING HANDLE. That goes for any charging operation for fear of a cook off or AD. If you are above gun reaching down just reverse because of position, but never wrap your thumb in a full grip or clutch the charging handle in a way that if it dischages you break a thumb, sprain your wrist. The cupped hand method was developed and soldiers trained on for a reason. It may still hurt as the handle is ripped from your hand but far less that slamming into it. The palm up method also takes advantage of your stronger muscles,essentially a curl, palm down uses more ofyour weaker muscles along top of forearm. Only reason I mention palm down is sometimes standing over gun working on it but as you have found out these need a bit of muscle from time to time