Resurrecting this year old thread because I finally have something to contribute.
Went to the range today and dragged out the chronograph.
Chronograph set 12' from muzzle. Kimber 84L 24" barrel
All loads were COAL 3.300" which is about .030" off the lands.
1 round to verify previous testing, this is my previous load for 150 grain Partitions. Win 1x brass WLRP 56.5 grains H4831 150gr Partition 2805fps The Hodgdon max load for H4831 and a HDY SP is 55.7 grains , so I am over that by almost a full grain.
Nos 0x brass WLRP 61 grains IMR 7977 150gr Partition 2953fps 2938fps The Hodgdon max load for IMR7977 with a 150gr HDY SP is 60.8 grains, I rounded up to 61 grains.
Rem 1x brass Fed 210 60 grains RL26 150gr Partition 3081fps 3090fps Alliant's website shows a max of 60.8 grains of RE26 with a 150 Partition. I had some old Remington brass already sized and primed with Fed 210 primers so I just went with it. I had 3 rounds loaded, but after seeing the first 2 readings I stopped. Thought I may have inadvertently overdosed the powder. Just pulled the bullet on the unfired round and weighed the powder, 60 grains exactly. Looks like RE26 is indeed the magic powder for 150s in the 270. It was a little breezy to do accuracy testing, but all 9 rounds shot into a little over 2" at 100 yards.
Looks like the modern 270 no longer needs 130 grain bullets or 4831 powder.
