Thursday, January 10, 2019

DPMS Oracle: The red line is between 19.5gr and 20.0gr of H-4895

The Oracle coughed up a hairball at 19.5 grains of H-4895, Rem 71/2 primer 55gr soft-point, 2.25" COAL, no crimp. Forearm was supported with an open palm and trigger arm and wrist were perpendicular to the barrel and as "loose" as practical.

Three-of-five were misfeeds. The weird thing is I think I experienced three separate failure modes.

One was failure-to-feed from the magazine to the chamber with the round wedged diagonally in the receiver.

One left no indent on the primer so I speculate that the trigger did not engage the hammer.

The third was failure to strip the cartridge from the magazine.

I am comfortable saying that if you want to confirm that your "home brew" AR is as "gassed" as a DPMS Oracle then it needs to feed-and-fire five-of-five rounds as above except that they are loaded with 20gr of H-4895.

For a frame of reference, a typical powder load for this powder and a 55gr cup-and-core bullet might vary between 24.5gr-and-26.0gr.

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