Cast bullet loads??

[imarangemaster]

CAST BULLET UPDATE:

I shot 50 rounds of the 115 Bear Creek / 11 grains Alliant 2400 loads tonight. Feeding was 100% from a USGI "J" 30 round magazine. I really could not tell any difference in feel of the action cycling between the 1725 fps 115 grainers and the 1950 fps ball rounds. I was mainly just checking for function and feeding before I load more, and was only shooting at 25 yards using headlights for light, leaning through the open passenger side door of my patrol Wrangler 4X4, resting on the door through the open window .

Best 5 shot group could be covered with a 50 cent piece! Horizontally, it prints identical to 110 FMJ Remington factory. No surprise was that it centered vertically about 3/4" lower (slower, heavier bullets print lower). I am guessing my assumption is correct that I will have to use the 200 yard setting instead of the 100/150 for 100 yard shooting. The only problem I had was two failures to fire. 2/50 dead primers would be unusual, so I looked closely at the rounds. They looked like light primer strikes, which puzzled me, as hundreds of rounds have all gone bang, even 48 of the 50 reloads. I checked the crimp, and both rounds seemed to be crimped too much by the factory crimp die. If it is too crimped, it will screw up the head spacing! I suspect the rounds are too tapered. I really think with the .309 cast bullets, I may just use the taper crimp, BARELY crimping, since the case mouth is sized .307, and the projectiles are snug in the cases already. The LEE factory crimp die seems to put a VERY heavy crimp on it, especially considering the 30 Carbine headspaces on the case mouth.

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[Patrick Chadwick]

The LEE factory crimp die seems to put a VERY heavy crimp on it, especially considering the 30 Carbine headspaces on the case mouth.

Then back it off a bit and lock the nut accordingly. With case crimping, I inspect the first rounds under a watchmakers eyeglass, and set the die so the the case mouth is barely tighter than parallel. Without the eyeglass, all you can see is a slight shine on the last fraction of a millimeter, where the crimp die has taken out the flare on the mouth.

To keep this kind of sensitive setting, my dies now have nuts with a locking grub screw. And a witness mark to show if the setting has shifted.