I have read in the Lyman 3rd edition cast Loads that a gas check is not needed if velocity is kept below 1600 feet per second and the bullet is a No.2 alloy or harder. Is this true? What is your experience. I was given some Oregon Trail Laser cast bullets in .30 cal. and am considering using them with 12.0 grains of Unique for about 1500 Feet per second.