I had a custom-built rifle on Remington 700 blueprinted action, during warm weather no problems, however, when the temp dropped below 30 degrees I had several misfires. The problem was small shaving inside bolt from when it was manufactured, just enough resistance to cause a delayed light strike. Pulled firing pin, changed to 28 lb spring, polished firing pin, cleaned inside of bolt body, lubed then wiped off all excess, and never had another problem. What was the temperature that the misfires happened?