09-23-2022, 06:50 PM
This was new unfired Lapua brass. It was sized (neck only - no shoulder set back as it was already well back). My rifle's fired cartridges measured with the B350 Hornady HS gauge come out around 1.221". I just checked a few of the unfired cases, and they vary quite a bit from 1.2045 to 1.220 - everywhere from 17 thousandths to 1 undersize. Hmmm... I am learning. At this point - I will have to treat all new brass as "need to pre-fire with reduced load to blow out shoulder to spec"... This has not been a part of my general practice. As far as bullet length - I measured the case to lands max with the Hornady COL gauge at 2.310 and CBTO at 1.736, so I don't think this was a bullet getting stuck in the land as my COL on these were 2.250 and CBTO at 1.678.