Originally Posted by Dexter Grayson
I actually went to the range yesterday with loads using 1 gr and 2 gr less than previous and the pressure went down but the groups were terrible.
Should I back it off a grain or two and do a seating depth ladder.
It would take forever for me to list the load combos I've tried so far.
If you found a load that shoots good with RL17 and the 180 AB, I do not think you need to repeat all of your other loads. Generally speaking a barrel should have a sweet spot (node) at least every 100 fps. when you are not in a sweet spot, it will throw them all over the place. When you are in the sweet spot, life is good. It looks like dropping 1 to 2 grains is not in a sweet spot.
So your current 66.0 grains shoots great, but is right on the edge of max pressure. you know that 64 and 65 grains do not work. I would probably try 3-shot groups with the following:
Typically a sweet spot will shoot to the same point of impact over about a 1 grain variation (all rifles will vary). Hypothetically, you might find that 62.0, 62.5 and 63.0 all shoot to the same point of impact with very good accuracy... If that were the case I would load all of my hunting loads at 62.5 to be in the middle of that sweet spot. Then if you encounter some temp sensitivity above 70 degrees, you will still be within your sweet spot and same point of impact.