Several months ago I received the Lee TL309 230 5R mould from Titan Reloading - one of our sponsors . The fastest twist 30 calibre rifle I own is the custom made falling block featured in my avatar which is in 30-06 and has a 1 in 10 twist barrel . I realized that this twist would be marginal with such a long boolit , especially at the sub-sonic velocity I wished to employ but I bought the mould anyway . At worst I am only out twenty dollars .
The mould was given the usual scrubbing and de-burring before casting commenced , a pot of alloy was prepared and a couple of hundred were cast over two hours or so . The boolits weighed just over 230 grains , measured .311" and after a week or two the Brinnell hardness was 16 .
I set up my lathe with a 5/16" collet chuck , ground a thin parting tool and machined the pointed nose off the boolit , removing about 200 thousandths creating a meplat of 0.220". An internal stop inside the collet provides repeatability and two to three boolits a minute can be modified this way . The modified boolit weighs just under 220 grains .
Tumble lubed with Lee Liquid Alox and loaded in front of 10 grains of Trail Boss they are shooting very close to MOA at 50 metres . Velocity 1090 fps .Attachment 97638