I think this mold will be a picky mold for proper velocity. see my text below.
Quick update with a shot report. I didn't have any empty 6.5 Grendel Brass available for reloading but I did have a bunch of primed 6.5 Creedmoor (Win LR primers) brass sitting on the shelf.
I got the new LEE Mold from Midsouth 3 weeks ago but yesterday was the first day I could cast, pc coat & size and then load them for a test at the rifle club this morning.
I used the same load data I have previously used for my Lyman 266369 (140gr RN) that has given me great 50 and 100 yard accuracy out of my AR10 rifle in the past.
So, the particulars:
LEE 140gr FN-Spirepoint (I don't recall LEE or Midsouth actually naming its specific profile on this mold so this is my description of it)
Lead range alloy popped out at ~140gr when dropped out of the mold to aircool.
Coated with single coat of Eastwood Blue PC powder before sizing and checking. weight at ~143gr after sizing and check steps.
sized at .266" with a Lee Sizing die.
Gaschecked with an Aluminum GatorCheck
powder: 28gr of IMR 4895
bullet seated right after the top lube ring and as the bullet begins its nose taper to ensure the nose didn't bind in my tight chamber and prevent full seating of the bolt carrier group.
overall cartridge length was well within the AR-10 mag length limits
expected velocity was to be about 2100fps with the 20' barrel.
cartridge fired, ejected and cycled the next round with no problems. Most brass went out at 3 o'clock while the 266369 bullet/load combo shot them out at around 5 o'clock. minor datum point but one that may help to determine the better cartridge)
recoil was mild as befitted the reduced load velocity (600fps slower than my comparable jacketed load with a Hornady 140gr ELD)
accuracy....yeah. Its got to go back to the bench as it didn't match the older Lyman bullet design for accuracy and there was a sign of two of the 20 shot beginning to tip at 50 yards. I need to try a slower velocity load (around 1600fps) as well as potentially a faster load closer to 2200-2400 fps to determine which is better for my 1-8" twist barrel.
20 rounds averaged 2105fps over the Chrony. Grouping was minute of wheelbarrow...
So I know my powder throw and brass prep is pretty consistent so that leaves me with trying to find the perfect velocity for this cast boolit and perhaps deciding if the TC Spirepoint is actually better than bore-riding 266369.
This powder load and size combo with a Lyman 266369 bullet in the same 1-8" AR10 gives me 3MOA at 100 and very tight groups at 50 yards but it was not having any luck today with the new bullet. today was about using all of the target frame and getting my money's worth out of the target...
I also will try a different load combo next time to see if its not a n IMR-4985 issue. Might even try to use it in my Grendel for next time's feedback.
Bruce