Took the Grendel to the range late this morning. What I consider high temperature and high humidity caused water to condense on the rifle, that is stored in air conditioning. The scope lenses also fogged, so I had to wait to start shooting.
I had 3 loads each with 2 different powders. The groups were inconsistent at best. Seems the Grendel is a bit finnicky about powder charge weights. A 0.3 grain difference can be significant. To make things worse, after getting home, I noticed that the linear compensator had loosened. Now I'll need to redo the experiment.
Oh well, a bad day at the range is better than a good day at work.
- - - - - - Update 7/12
Reran the previous load testing with the linear compensator remaining tight. Three of the loads are worth running again, two with TAC and one with 8308. Both pushing 120 grain Sierra Game Kings. It seems the barrel likes velocity in the 2400-2500 f/s range. Once I determine the best load I'll play with the compensator location to see if I can tighten the groups by changing the the barrel harmonics a bit.
