Yosey, Your right about not shooting your gun much.. you said it was made in 90-91 so its about 29 years old and you bought it new shooting only 400 rounds. That`s not much at all.. What did the erosion on your gun look like?? My FA 454 is 24 years old and I really don`t know how many rounds I shot with most of them being factory or factory equivalent handloads but I can say I would handload until I filled a coffee can for a range day. 99.9% were jacketed bullets. The tiny knicks I mentioned above are the only thing out of ordinary.. Maybe Rey was right saying you may have forgot using Lilgun cause that`s the only way I can see eroding the barrel with 400 rounds...