I had decided to use .223 Accurate Mags for my 6mm x45 build. The Accurate Mags have a published max OAL of 2.325". I measured my Shilen barrel and had determined that for 107gr Sierra Matchkings I needed to set my ogive at 1.910",.010" off the lands therefore with an OAL of 2.480".


Fortunately the Accurate Mags can be modified to increase the OAL by a little Dremel and flat file work. The modification now gives me a 2.538" max OAL.