This may be a stupid question but I am relatively new to hunting...3 years now and only 2 rifles. First worked well with the ammo I got with it so I never changed and now I have a browning x-bolt 300WSM. I am trying to find a good factory load for shooting out to say 300 yards with decent accuracy but I do not have hundreds of dollars to try LOTS of different brands so I am limiting myself to just a hand full of the popular ones. That being said, I have shot 2 types so far. 180 grain Super Xs and 165 grain fusions. The 180 grain super Xs grouped poorly and was evident at 200 yards....7 inch groups! while the 165 fusions grouped pretty well...about 1inch at 100 yards...even better when I really concentrated so I am guessing someone with a ULTRA steady arm could group it even better. I am using sand bags but still learning to shoot better...no leadsled to use or borrow so sand bags is the best I can do. My question is does the 180 super X give indication that all 180grain bullet ammo including other brands will most likely perform bad or does rifle accuracy change brand to brand and even bullet weight to bullet weight within those brands? For example 180 super X sucked, but maybe 180grain remington corelocks might be good...maybe not.