Some of the NEF rifles need to be free floated. Some of the guys put a small rubber O ring on the barrel stud to relieve pressure against the barrel. The forend is usually the problem. Also check and see if the fit is to tight beteen the cap on the rear of the forend and the reciever. Also you might want to polish the bore or except the idea that it migh take few hundred rounds for the barrel to start shooting well. Another thing to try, If your useing a rest, Keep it as close to the reciever as you can. Make sure the rest it in the same spot all the time. Repeat procedure is important to getting good groups with these rifles though thier hunting acccuracy is quite good. On one of mine I put two or three strips of mounting tape side ways on the forend in the barrel channel. My idea was to try anything to keep equal pressure between the barrel and forearm. If you need to take the little cap off the near end of the forearm and sand just a little off so the cap is not putting pressure against the reciever. Sometimes these little rifles take a little time and tinkering to make them shoot good. For some of us diehard NEF nut, this was half the fun.
My NEF 280 has the 26 inch barrel and shoots about 1 1/2 inch groups. The good thing is that although the groups are not real tigh, it never misses the X buy moe that an inch in any direction. It has what I call good hunting accuracy, your going to hit awful close to where you hold. Some NEF rifles seem to shoot better with the lighter bullets for caliber. If you stick with it I think you will find it will shoot pretty well.
One last thing Clean the rifle very well to start. Clean everything that you can get to. When yo finish cleaning the bore, its best to set them muzzle down. If you don't then any left over oil and stuff will run down into the chamber and may cause cases to stick. In other guns this oil can run out of the bore but on the break action the oil is trapped in the chamber. Sorry this got so long but these rifles hold a spot close to my heart You can polish the bore by repeated strokes with patches coated with Flitz metal polish. Then claen the bore real good.
One more last last thing. Many of the rifles have quite a bit of free bore so if you load you may want to seat the bullets out accordingly. However to great of OCL or long casings can cause them to stick in the bore when trying to unload a full cartridge. They will ussually pop out after you fire them in this case.