Re: Long Distance Load Tuning
My suggestions would be:
a) Sierra manual shows 50.9 max load for imr4831 in their 117 gr SBT’s, IMO check for pressure signs and check berger manuals, seems quite hot..
b) You cant force a bad load to be good, go with what the data is telling you,
c) don’t change seating depths while testing a load, and if you did not, only when you find the right powder and charge wt, then fine tune by adjusting seating depth,
d) You may have seated too close to begin with, granted they are 115 bergers, either try a diff bullet or differeint powder, (Retumbo, RE-22, RE-25, h4831, I have found all these good powders with the 25-06), seat .020 off and work closer in .005 increments, but only after you find a good powder charge. (use chrony for pressure spikes when close or at the lands, be careful).
e) How are you prepping your brass, and what is your full recipe? Are you using the same die process for each and every case? IMO bag the FL die for a necksizer..and get a Redding body die to bump the shoulders…
f) Keep testing at 100 , IMO only when you feel confident in your reloading and bench technique should you move out to 200…