Greetings,
I had a 300 WSM built using a Defiance Machine receiver with a Bartlein barrel. To break in the barrel (using Barnes TSX factory 165gr ammo) I shot once - cleaned once for the first 10 rounds, then three and clean to finish the box. Closing the bolt on the first two rounds seemed tight and then the rest closed the bolt like normal. The last several were tight to lift the bolt after firing. The last group was 1 1/8" at 100 yds.
I then went out a week later with a box of Federal 180gr soft points. I fired five rounds with no bolt close or lift issues. 3 1/4" group at 100 yds. These seem like terrible groups.
Most all the fired brass had ejector marks where the brass had a raised mark from the ejector hole. All fired primers seemed normal and the same as the fired brass in my 308 Tikka.
Any ideas or suggestions?
Thanks in advance for your wisdom.