That stuff is magic fairy dust. Maybe someday. HahahaI think you just have a one of those barrels. All of the numbers confuse people. It's the lands, grooves and throat that cause the most change to your loads. The lot of powder can also play big role in it too sometimes. (Why I don't buy one lb of powder at a time, and try to buy at least 5lbs off ogf the same lot#) What you are seeing is normal. How is the case fill? Maybe try retumbo or n570?
You have a new barrel running mid 29's with a 143. Seems pretty spot on to me. It will speed up around 150-200 rounds likely.I'm being a little dramatic. The gun is shooting fine at a velocity that I was hoping for just more pressure than I would like. Based off the wheeler video it sounds like I might not actually be hitting pressure as much as its just a tight chamber. The load i am settling on for now is 2960 avg which is totally fine with me but I am going to see what I can do in the accuracy department and try another powder. Its right at 1/2 moa which is acceptable but I want to see if the gun will do a little better, that's part of the fun for me anyway. I will say that this is the 2nd McGowan barrel I own and neither have impressed me thus far but thats a sperate topic.
I wonder about the chamber or even the barrel being too tight?I have a newly barreled 6.5 PRC that I am hitting pressure with a modest load of H1000 and 143gr ELDs. Book max said 59.0 gr and in my experience with every other gun I have ever shot the book max is still under what the gun will actually do. I started hitting pressure at a modest 56.5gr of H1000, Nosler Brass, and a FED 215. By 57.5gr I gave up when I started getting a heavy bolt lift. Any ideas on why? I know every gun is a little different but this seems extreme. Could the chamber be a little too tight?
It sounds like your chamber is a little too tight.Jump is .050" that i settled on. And now that I think about it some of the Hornady factory ammo was a bit tight like a handload that didn't have enough shoulder bump.