I have a lot of gear, it is useful. Do this, go camping Friday through Sunday, take everything you THINK you need in your pack. If you go anywhere take the pack. Figure how much 300 rounds weigh and substitute with something of equal weight and mass. Get a plastic bat fill with cement to simulate a rifle, again this rifle goes where you go. No cheating, if it don't fit in the pack or tied to the pack it stays in the rear (home).
My 120 pounds or so 3 day pack is now a modest 70 pound pack. There's stuff I'd like to have but it makes finishing an op more enjoyable. Coming back to a soft pad on a cot, getting a solid hot meal, or maybe just a cup of Earl Gray to wind down.
If you're honest on this you'll end up with what you NEED.
Also rage pen and paper if you think of something you don't have write it down and why. When you decide you don't need it write it down and why. Next time you go try out the new stuff that made your list. This list will never quit changing I promise. You'll wind up with a list for all seasons it all starts with a list the first one I started was a list of lists.
None of this is my idea just things I've read here and elsewhere. Now is the time to practice and see what works, is hate to lose something I really need at camp just because I thought I may need it on a long patrol so I ditched it because of weight and hadn't used it for 3 days. One more thing I live in bear country so regardless of things I carry when I go.