I recently inherited a 50's year model 760 Remington in a .270 cal. I cleaned it and took it to the range to sight it in. Fired one round and the entire mechanism locked up. I took it to a reputable gunsmith, he told me that he may not be able to repair this problem. he said that this problem was common and that even the factory could not repair this issue. Does anyone have any info on this condition and waht can be done about it? This was my grandfathers favorite deer rifle and i would love to pass it on to my son.