Many published maximum loads indicate compressed charges. Does anyone know how much compression is safe? At some point there must be a risk of breaking granules and causing a sudden increase in burn rate. My specific problem concerns my version of .300 Blackout optimized for light to medium weight bullets. Case neck is .150" longer than standard to allow seating 125gr bullets to magazine length. I have not been able to find Ac 1680, and H110 starts showing pressure signs before reaching target velocity. Ac 2200 shows no sign of excessive pressure with the case filled to bullet base. At that point velocity is just reaching the lower end of the velocity range that I hope to reach.