Like I said, old rifle, lot of rounds, tried .010 off back out to SAAMI and never could get it to smile with the 200ELDX. If you are ok with 1 MOA it did that consistently with the 200ELDX. Burned a lot of powder trying to get it where the 200AB shot but never could. Since I have killed a lot of animals with the 200AB, it just wasn't worth burning up barrel round count to me. I had a 196HH load within 20 rounds, that is now my primary 300WM load. The 200AB is still a favorite due to high confidence I have in it.
You are prob right I used wrong term on stability but it just wouldn't deliver the accuracy and velocity I can get with other bullets.
I will clarify one aspect of the 200ELDX that I saw in load development. It shot pretty good at 2775 but faster I drove it the accuracy dropped. Maybe stay there, save brass and still decent for range I would shoot but the 200AB shot great at 2950 which I felt better option. The 196HH is at 3150 so still better for me.
The 200 ELDX is the only 200 gr lead core that did not shoot well in this rifle at velocities I expect in a 300WM. Heck, I tried box of Precision Ammo which shoots at 2850 fps and still did not shoot as well as the 200AB. Finicky rifle? Finicky loose nut behind it? All of the above?