Hi all. New member here. I have a Gunwerks Magnus in 6.5 Creedmoor. Been seeing a small nick or burr on about 1/3 of my fired case mouths. It's 4x fired Lapua SRP brass, annealed, and FL sized w/ Type S dies using 0.291" neck bushing. Neck tension right at a thou. Shoulders were bumped 0.002". Charge is 41.4 gr H4350 with 140 gr ELDM's on top, seated 0.010" off lands. CCI 450 primers. After sizing, all cases measured under recommended trim-to with an avg. of 1.908" so I didn't neck trim. The weird thing is that some cases that were slightly longer have no marks. No pressure signs at all, which is no surprise at 2725 fps. Anyway, I wanted to pick y'all's collective brains and get some ideas about what might be happening. Nothing on YouTube or Google searches tell me anything. I attached a picture. Any advice will be greatly appreciated. Thanks!
- Thread starter rodi53
- Start date
Hard to see in the pic but it’s likely cause by ejection. Next time you shoot carefully remove the fired cases for a handful of them and see if that stops it. Not a big deal either way. You might see evidence of the impact on the side of your receiver, scope rail, or scope.
There's gotta be something in the chamber that's causing that. The best way to see what it might be is to look at your chamber with a bore scope. A bore scope that works very well can be had for $50 . . . take a look at a Teslong bore scope.
Look like it hit on the lug abutments on ejection.
Thanks everyone. Makes perfect sense. I was looking at it from an "it must be my reloading" point of view. Much simpler than that it seems. I bench shoot the rifle and reach across to catch each case so it doesn't hit the ground. I appreciate the advice! I'll be heading out as soon as the sun rises to run a ladder test on a 6BR and will take the Magnus with me to verify, but I think you guys nailed it.
If you can remove your ejector and fish a few fired cases out of the action by hand I’ll bet those dings will go away. As others have said, chances are it is getting snagged somewhere during the ejection process.
If its what steelhead said catching it once its out of the action wont help.
Lots of times that ding happens when the brass is getting extracted from the chamber but still inside that action. The ejector spring is pushing on the cases side at the back which is what flips it out the ejection port when its clear. But when it clears the barrel chamber it can still flip out inside of the action and catch that neck bit on the actions internal lugs.
If thats where its happening then sanding that corner a smidgen will help with the sharp cut or if its smooth already and its just top much force you cold cut a coil of the ejector spring and lessen the ejection force so that it doesnt flip it into the action walls so hard.
