Thread: Bullet Seating depth and pressure (6.5 Grendel)

Originally Posted by PommyMcPomFace

Yes, seating deeper increases pressure. But 0.020" won't cause a safe load to become dangerously unsafe.

Seating longer can also increase pressure. Without a run up to the rifling, more pressure builds up in the chamber before the bullet gets moving.

My load is 27.6gr of BM8208 with the 123gr ELD-M. I get faint ejector marks too. I've gone up to 28.5gr and it was very accurate but the bolt was starting to get sticky.

That's interesting since we've both come to almost the exact same load. Is that what you are using on a regular basis ?
My thinking is that I am obviously very near max pressure and if seated close to the rifling without a big jump it is increasing the pressure, seating a smidge deeper must help give it a a "run up" (like that) as you say and very slightly reduce the pressure. But if continued to seat deeper and deeper there will come a time when case capacity has decreased so much and you have a compressed load and high pressure again ?