Many years ago I bought 2-V51 pistols. On one I opened up the box and checked all the disassembly and fitment. The other I stored in a dehumidified safe for storage until now. When disassembling for removing the cosmoline and fitting, I noticed the end cap was a bear to take off and needed to be taped off with a brass dowel. After cleaning and fitting on and off several times it was better, but still needs to be a lot looser. The bolt assembly slides in and out pretty easy, but has a small amount of resistance at the end coming out. Any thoughts or advise?