You can't (at least should not) use .22 lr in a .22 mag gun. The diameter of the magnum case is larger than the long rifle case. The long rifle uses a heeled bullet and the case diameter is the same as the bullet diameter. The magnum does not use a heeled bullet and the case diameter is greater than the bullet diameter. Fireing a long rifle in a magnum chamber will likely result in a ruptured case and could even injure the shooter.
The bullet diameters are the same which is why a convertible revolver with two cylinders can fire both rounds.
The bullet diameters are the same which is why a convertible revolver with two cylinders can fire both rounds.