If your rifle is 100 percent reliable with factory ammunition, you are doing something that is affecting your primers. Most likely two possible causes.
1. you are not seating the primers properly. Primers should be seated either flush with the case head, or slightly (.001 to .003) below the case head.
2. You are contaminating the primers with some type of petroleum product, either oil or grease. Solvents and primers do not mix! If your equipment requires you to handle primers, be sure your hands are clean and dry.