Congrats on the 336!!! [8D]

I love my Marlin 30AS (cheaper version of your 336 - but essentially the same gun). Mine loves Remington Core-Lokt 170gr. The 150's are okay too, but don't pack the oomph that the 170's do.

The 150's will fly out there a hair more straighter with a hair more fps than the 170's. But for deer hunting and maximum penetration and power, most people go with the 170 grains.

Good luck and enjoy the 336!!!