End of this video is good recap on the Sierra 2900s

https://www.youtube.com/watch?v=lCtvdRHVeaE

Not quite the math of a 35 Whelen, but very much the math of a .375 Whelen.

https://en.wikipedia.org/wiki/.375_SOCOM

https://en.wikipedia.org/wiki/.35_Whelen

https://en.wikipedia.org/wiki/.375_Whelen

Probably the most formidable AR-15 round ever devised out to 250-300 yards.

Neck and neck with the .358 Winchester

https://en.wikipedia.org/wiki/.358_Winchester

If you are not actively engaging EVERY enemy you encounter... you are allowing another to fight for you... and that is cowardice... plain and simple.