It appears your rilfe is a Marlin 30-30, and I'm guessing you're talking about a bullet for
deer hunting application. As noted, best to try out a few different brands, and bullet weights to see what shoots best in your particular rifle. Look to the 150gr. or 170gr. for
deer hunting. My own preference is for the 170gr. as it has a little higher sectional density, and can generally be counted on for a little deeper penetration - maybe not a
whole lot of difference, but I'll take any advantage I can get.
An excellent load for me/my rifle (was also a Marlin 30-30) was the Remington 170gr.
Core-Lokt. Also, the Federal Premium 170gr. Nosler Partition load.