If you ever wondered how much difference seating depth can make here is a good example. I started at 300yds with bullets jammed .010" and shot a ladder to find pressure ceiling and node. I settled on a node that went from 72.5gn to 73.5gn then went back and shot a 5-shot group of 72.5gn, 73gn, and 73.5gn with bullets jammed .010" to see what showed least vertical. Since 73gn showed least vertical and POI was within an inch for all three charges at 300yds I stuck with 73gn. Because measuring bullets has shown bearing surface length variations of about .010-.015" on Sierra bullets I never seat less than .020" when shooting the SMK. Below is 73gn of RL22 with a 190gn SMK jumping .020", .030", and .040" today at 300yds. Winds were 14mph on average, low of 11.8mph, and high of 21.1mph so it is possible I missed a call on the .020" target but I don't think so since I was on it for the other two and it was only 300yds.
.020" jump wasn't worth measuring, .030" was in between (probably 1MoA-ish), but .040" was the winner at just under .5MoA with shrinking verical as I drew the bullet back from the rifling.
Now I just need to load up a 10-shot group to make sure everything is Kosher and then I'll take 100 rounds out to the 1000m KD range in a couple weeks to collect drops.
Yep, I do the same once I have found my optimum charge. I really like how Berger recommends you find the best seating depth. It works very well. I shoot the groups round robin so fouling is not a player in load choice. Here is my load workup for a 25-06. This same load is producing MOA 5-shot groups at 600 yards which I feel is my limit for this cartridge.
I agree on secant designs but with Sierra I have never had to go deeper than .060" and that was a magazine restriction so I normally start at .020" and go back by .010" and find the sweet spot between .020" and .040" from lands. Hornady A-MAX or Sierra TMK I jump in bigger increments. I only shoot Berger Hybrid so I normally follow my Sierra bullet routine.
Will throat erosion occur faster with jumping the bullet or one that is jammed some what? I never gave much thought to this as for hunting I would seat the bullet enough to work OK in the magazine. I take the bullet that I want to check depth and cut a slit in the neck put it in the rifle and jam the bullet in then I back off a little and make sure they fit in the magazine
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I was loading some .223 this morning and in for that Wylde chamber a 75gn Hornady OTM is jumping .117" to the rifling. In this case it is because of mag length restrictions in the small frame AR. That gun will hold X-Ring elevation at 600yds.