Free: Contests & Raffles.
The reason there are so many Ruger upgrades is because they're necessary.
I am actually mostly talking out the other end. I do know I can feed an m-4 absolute crap army ammo (bent, scuffed, chipped) and they all them to get where I point them at and be set up for the next shot.
Not knowing much about a M-4. But from just reading it sounds like your SB die isn't going full length. Thats from using SB's on 243's and 06's the other is that the brass is too long and needs trimmed. Both of which will cause headaches. My first choice would be take another 1/8th of a turn on the dies.