You can use standard primers and they work fine.... until one day it does not.
The primer pressure will pop the bullet out of the case and into the barrel throat. If you are lucky, it won't go far and the next round won't chamber.
If you are shooting rapid fire and the next round does chamber, it can get interesting.
The problem with a standard primer is that it just barely gives enough fire and pressure to ignite a load of BLC2.
If the neck tension is light (old brass that needs annealing) and poorly crimped, that will reduce ignition. If the the load is a mild one, the extra air volume in the case reduces ignition pressure and the round can squib.
When I was loading 223 with 55s and BLC2 for CQB (50 yards) I tried reducing the powder charge. I did not need the extra velocity and recoil. As I reduced the powder charge, the ignition failure rate went from zero (max charge) to 10% failure (mild load).
I had about 1000 rounds loaded that gave 10% failure. I used them up by running them through the Dillon and applying a max crimp. Then they were almost perfect.
In general, when making ammo, you want 150% of the ignition energy required; not 102%. You generally can't tell that you are on the cusp, until it is too late. This is why the book says use magnum primers with ball powders. This becomes more important the lighter the bullet.
I use to target shoot with 80gr bullets and used ball powder (Winchester 755). I never used a magnum primer. No need with a full charge and a heavy bullet.
