Well, a while back I had feeding trouble trying to load 130 Sierra SBT, 210 primer and IMR 4064 in 270 Win for my 7400 autoloader. I lowered the COL from 3.3" to 3.275" with 47g of 4064 and ejecting was fine. Accuracy hurt a little, but I still
am consistently getting 1.1" groups. Hard for me to believe with a 7400. With factory Corelokts, it always got 2"-3". Tried 47.5g, and 48g at 3.3" COL and groups opened. Anything below 47g and it won't load the new round properly. If you try to load 3.3" with 47g, it won't load properly.
Seems to be a small window of operation for this round in a Semi-auto. At least with 4064.
130gr hor. sp same basic load 54gr h-414
3100f/s this is a max load in my 270 7400 rem. killed 3 deer this fall with this load all 1 shot kills all around 150yds.. 3 shot groups 1" @ 100 yds.
I use mag primers in all my 270 loads also oal for nosler ballistic tip at 3.25"
looks like your on to it.
dave