Picked up a FPK dragunov (over grown AK) at a texas gunshow. Put 200 round though to break-in, at 160 rounds had a broke casing, finished rest of the rounds with no problems. When i picked up the casings had 3 split necks and 23 buldged cases at the base. While cleaning the weapon, the front trunnon had been spot-welded and was cracked. checked headspacing it is off, looks like the barrel has moved forward. Can the barrel be pushed back and redrill the barrel pin hole and replace the barrel pin with a larger one? Any help will be greatly appreciated.