Here is what is known:
.277 Dia 130 gr. HP with what appears to be two cannelures first cannelure is at upper 1/3 of bullet and next is at lower 1/3.

I have determined bullet not manufactured by Hornady, Sierra, or Speer.

If memory serves me correctly, Remington made some bullets for reloaders with two cannelures to facilitate different seating depths.

The 140 grain Remington 6.5 psp bullets I've used had two cannelures also. roger