Originally Posted By: 204 ARI'm not surprised 4227 will not cycle your AR. Port pressure has to be awful low with that fast of a burning powder. Try 8208 or something in that range and your issues will go away.
The creator of the bullets says to start work with the max load (seemed goofy to me, so I just smaller ladders to look for pressure) but didn't see any extreme signs once I got to max with the 4227. Would getting a copy of quickload allow me to enter my case capacity, barrel length, etc. in to build a custom cartridge?