Bought a NEF H&R Aug 07'. 2 boxes of Magtech 275 Gr Bullets, SCHP. Scope Leopold 4 power fixed. Sighting in with a Lead sled. After sighting and using a box of ammo. I thought I was ready to go hunting. Missed both deer, Under 100Yds. Set the gun aside till this July. Went to sight it back in with a new box of Hornady 300 Gr. SST/FFT. At 50 yards I was all over the place. I/2 box of ammo. Sent Scope into Leopold Received it back in Sept and again started to sight in. At 50 yds was on the paper (3 shots) and went to 100yds up to a 3 Foot spread Over the next 12 shots the barrel release jammed, had to be pried on then after several shots was OK. Went back to the Magtech 275 Gr SCHP(had 10 left) and got it down to a 12" MOA. At the cost of ammo I need some help on where to look first. I do notice some Barrel movement went closed. Also the front rest was at the end of the forearm.