Looking at the 2 targets posted , to me you have double grouping with a flyer. I would have shot the rifle first before sanding off the front pressure points in the stock.
I think it’s hard to get a factory barrel and factory ammo to shoot sub-MOA on any given day. You may come across one lot...
I tend to agree with your assessment on the 0.558 being a bit steep. They don’t have that sleek long nose to help in the BC department. With the larger open tip I bet they will be devastating on game like the Shock Hammers.
I’m guessing there were different load charges in there. If it was a work up to find max pressure , you’re best to pull and start over.
I mark primers with different color markers to avoid any mix ups.
My 338 WM is in a Wby Vanguard and is a little stinker for consistent groups. H4350 is where I was focused on last year. The 210gr TTSX does soot well in this rifle.
As for brass I’m running 7mm RM Peterson. As JD mentioned , expand to 308 then 338 load and shoot.
RIP Mr. Tubb.
I had the pleasure over the years talking on the phone with him on some of his products. Every time I called he would answer the phone. Truly an innovator in the shooting world.
I know the feeling of waiting , my 378 has been sitting at the ‘smith since Labor day. He does great work , just takes his time. Each rifle has taken about a year to get back. The best thing he is only 20+ miles away , no shipping.
One thing if it was a smokeless ML , they went and designed their load data around Blackhorn 209. Close to $200/lb powder that is scarce at best leaves me scratching my head.
I anneal after each firing to keep everything consistent for me. Brass work hardens from the firing and sizing of it and at some point the necks will get brittle and crack.
I’m in the same boat. I’m out to 6.5 months on my 458 barrel. When I ordered it lead times were 8-12 weeks , now they’re showing 4-12 months. I’ve seen the internet chatter also.
I have several weeks of vacation starting tomorrow and load development was on the plate for the 458.
I have a...