pins here
on the face of it, i would've thought that a spike of alluminium would have more luck deflecting an incoming arrow than a piece of plastic
since switching to navs with pins i have blown up about half a dozen nocks, including one that blew apart and it took a gouge out of the pin, but the shaft was fine. new pin was cheaper than a new arrow!
in saying that though beiter pins are expensive. i dont kill nearly enough to worry about the costs yet really, kill about 1 nock a fortnight but for the better shooters replacing them constantly must get very annoying indeed.