I load for a 10 FP Savage and my son and two range buddies each have the newer 10 FCP-Ks. We compile all our loading data and compare it so we have some pretty good idea of what our particular rifles prefer. We tend to be meticulous in measuring both while loading and in recording results so the data we have gathered gives us a pretty good idea of the similarities and differences in each of the 4 rifles.
Two of our rifles are slightly more accurate with 150 up to 168 bullet weights and the other two seem to prefer heavier bullets up to 175 grains. They all shoot all the weights well under 1 MOA.
Every rifle is different so your probably going to find that your Savage and Remington will like different bullet weights, seating depths, and powder loads too.
All our Savage Model 10 .308s have preferences for specific seating depths because all the chambers are slightly different.
One of our 4 chambers is very short and my chamber is very long. The other two fit right in the middle.
My barrel has over 5000 rounds through it and that sometimes accounts for chamber erosion but it still shoots great.
In fact it is shooting better now that I have started measuring all loads for chamber depth instead of measuring for overall cartridge length. Turns out that there is usually more variation in the bullet tip length than there is in the die, so measuring cartridge length to the bullet ogive is more accurate than measuring the OAL when seating.
There is a very good informational article in the new Berger Reloading Manual starting on page 148 that recommends that you set the bullet seating depth based upon the specific bullet you are using and on your particular chamber depth rather than based on the initial manufacturer's general recommendation (even theirs).
All of our Savages have had really good accuracy results with H4895.
I tried Vihta Vuori N140 powder over the last 5 months and have had the best results to date, probably because it meters so well.
Two of the other shooters have also switched and have similar improvements.
All of us have found that N140 shoots slightly slower than the H4895 but the groups are tighter.
The standard deviation in velocity through my chronograph with N140 is usually under 10 fps compared to 15 to 25 fps with some of the other powders.
IMO the two biggest contributors to accuracy in a hand load are consistent neck tension and consistent powder loads that yield the most consistent velocities. After that, consistent seating depth is the next big factor.
We have not had results as good with Varget or Reloader 15.