Gerard--

VERY INTERESTING!!

After reviewing your site I assume I note a 540 gr FN compatible with a 500 NE Double.

If the Double were shooting 570gr Woodleighs at 2150 fps, what velocity would be reasonable at acceptable pressures for your 540 gr FN?? 2200 fps? How about the 500 gr, 500NE bullet? 2300fps?

I am assuming these bullets would be stable and have less pressure expected vs conventional solids with no barrel damage to a Double due to your bullet construction design.