Between powder selection and bullet seating depth, "generally" which of these two components has the bigger impact on accuracy in any particular rifle? Along with that question if you were working up a hunting load that provided the best possible accuracy for your rifle and you wanted to choose one powder and then experiment with bullet seating depths what would be the best way to choose that one powder?

I don't know that one selection, powder or bullet seating depth, can be given an advantage over the other. In my experience it depends on the rifle, others may have a different experience.

Regarding powder choice I would choose the one that gives the highest percentage of case fill at the lowest pressure and gives the highest velocity.

When reloading for a purpose, I choose the bullet first then I look at the load data to find the highest velocity that runs about 90-100% of case volume. Then I look in my powder cabinet to see what appropriate powders I already have and start with that.

Then I start shooting for groups. I usually start .010" off the lands (.050" for Barnes) if the magazine will let me. Once I find an accurate powder load, I start moving the seating depth to fine tune it.

I agree with Frank.

After bullet selection, pick a powder. Go to the Sierra manual first. They recommend best powders for accuracy and hunting, often the same with a little difference in charge weight. To make the charge testing more efficient use either the Tubb ladder or Optimal Charge Weight system. You can Google 'em.

Seating depth either makes a big difference or it doesn't. (That's helpful, isn't it?) Some rifles are fussy, some not. Start close to the lands, maybe .010 off, as suggested.

To assure that your testing is effective brush up on your bench technique. No sense wasting powder and shot.

If you hit a snag, post again.

rushisright, No shortcuts here. The bane and beauty of reloading is working to customize the load for your specific rifle and target. Otherwise, why just not shoot factory ammunition? It's very good and does not cost THAT much more than quality reloads.

Bullet seating depth; no question. Then powder, but sometimes it is opposite. Maybe. Try it and see, for your rifle; that is the only way. No one can answer for your rifle.

I have found that the first variable is the bullet. Some bullets never shoot good groups in a particular rifle irrespective of the case, powder, primer or seating depth.

Once I am comfortable that the bullet will do say 2 inches minimum with the first reload, I might change the case brand from Norma to Winchester etc.

In my experience any bullet that gives a 2.5 to 3 inch group with the first try never improves to a 1 inch group.

I tend to limit the number of powders tried to 2 or 3 at the most - doing a lot research first before making the choice. I do not have the time or motivation anymore to experiment for the sake of experimenting!

Usually by the 3rd or 4th load I have a 1.5 inch group and velocity near the targeted level. Then it is fine tuning - adjust powder charge, seating depth, neck sizing, change primer, etc.

For hunting loads I do not worry too much about seating depth - standard rule is 0.020 to 0.030 inch off the lands for all hunting loads. Exception is Barnes monometal bullets - 0.050 inch off lands.

Most of my rifles shoot 1 inch 5 shot groups with this method and occasionally I get lucky and even get 0.5 inches for 5 shots. 3 shots groups of 1 inch are common. Any aberration is fixed by changing the bullet for that particular rifle.