Are there any other manufactures, other than H&N, that make different head sizes? I'm having accuracy problems with a gen2 22 caliber marauder. I've tried several brands of ammo out of the rifle and the best I can get is sub one inch groups at 25 yards. I removed the baffles and pulled several cleaning patches through the barrel, but it didn't seem to help any. The best accuracy is with H&N barracuda extremes, but like I said I'm just not getting acceptable accuracy. I have a couple 25 caliber PCP's that will shoot pellet on pellet at 25 yards and I was hoping to get that from this rifle. I have not tuned this rifle yet as I don't currently have a chrono. Any ideas?