I’ve never seen cratered primers in my break actions just flatten with new brass. I figured it was from the ignition of the charge backing the primer out slightly due to the extra headspace of the new brass. Then the brass under pressure expands to fill the chamber causing the primer to look...
Nice start with barrel break in.
Peterson Brass had 25 RPM on their sight for purchase or at least you can add it to the cart. It is under the in development tab.
https://petersoncartridge.com/products#!/25-Weatherby-RPM/p/827129547
Barnes list Hornady brass in their data which has more internal volume than Starline. Starline brass I use is the heaviest in a given caliber.
The brass you tested is it new or has it been fired. I fire my brass before serious load work up.
If you had to wrestle it open , you beyond the safe...
The rifle is a Weatherby Vanguard using Shilen’s Alternut prefit. This is the second one I’ve done with them.
https://www.shilen.com/alternutbarrels.html
All the brass fired in the old barrel will not work in this barrel , so I still have 40 pcs to work with.
It is hefty coming in at 11.6 lbs.
Earlier in the week we in the mid 90’s with dew points in the upper 70’s , your sweat was sweating. It’s amazing in 6 months you go from -30’s to 90’s here in WI. Factoring in windchill and heat index you’re talking over 150*.
Today’s smoke was better 3/4 mile visibility.
It’s been in the 90’s all week with tropical humidity here. I been trying to strip the paint of the deck and railing , but that just being done in the mornings. Yesterday we got a real kick in the teeth with wildfire smoke from Canada. Most of the day we only could muster 1/2 mile visibility.
Yesterday I received my Shilen 224 Wby barrel. After seeing how the 375 performed I went with them on this project. It is nice that they the Alternut prefits for the Vanguards at a reasonable price.
Both Natchez and Scheels have them , 200gr JSP.
https://www.natchezss.com/nosler-whitetail-country-rifle-ammunition-35-rem-200gr-sp-2075-fps-20ct
https://www.scheels.com/p/nosler-whitetail-country-35-remington-rifle-ammunition-20-round-box/54041-40141/