55 grain feeds fine but when I load the 62 grain ammo it fails to feed unless I manually feed it by hand operating the bolt on my AR-15. Could this be a weak magazine spring or am I looking at an issue with the bolt itself? This is wolf brand ammo and has functioned well in the past with the 55 gr bullet. OAL is 2.248 which is right on the money and comaparable with the 55gr.

I would bet it's a magazine issue. Most of the time it's caused by 30 round mags . The bullet tips touch were the mag bends and binds up everything. Try a different mag, a 20 round would be better and a straight 20 round would be best.

Terry