Originally Posted by
Jay Andrew
There’s a few things that could cause that.
1. Check to make sure you sizing die is sizing the neck of the case. If it doesn’t size the neck you won’t have any neck tension to hold the bullet in place. The .223 case should have enough tension to hold the bullet in place without a crimp.
2. The pull through button on the sizing die could be the wrong size. It size the neck down but you pull the button through and it sizes the case neck up in diameter. I used to modify the diameter of buttons to test the affects of neck tension on P/V in lab settings, but if this is a new die set check the diameter of the button, should be a few thou below bullet diameter.
3. Excessive lube in the neck. That would drastically lower neck tension and cause the bullet to set back in the case.
4. The cases weren’t sized at all. We all make mistakes, that could be one of them.
5. The feed ramps on the Mag aren’t allowing the cartridge to shift up and as a result it shoved the cartridge right into the ramp, instead of up the ramp.
AR’s can be pretty violent on loaded rounds. It’s normal to see the COAL shift a few thou on chambering/extraction. Especially on repeated chambering and extraction as the act of chambering acts like an inertial hammer.
Apply a crimp, even if it is slight will help to prevent that, however what you have is far beyond what a crimp should be preventing.
Reloading...it’s like knitting for men.