Rimmed case concern

Pictured are two rimmed cases. A 30/40 Krag and a .303. Both are new once fired cases and the Krag a Remington case and the .303 a PPU. Both have what looks to me like the beginning of a case failure. Or could this be a reflection of a dirty scratched or worn chamber between the two arms. Both rifles do not exhibit the same signs on every ejected round. The once fired 303.cases seem to have a more crazed appearance. Would some one advise for safety. Both rifles are clean and have given good service in the past. I do not own any head-space gauges for either caliber.
Thanks :sos:

If I am suspicious, I section the casehead, file clean, then look for the internal groove of an incipient separation. A probe can be used, feeling for the groove, but I prefer to cut the casehead open and have a good look.

I think you're being over concerned. I think that's normal case swell within those service rifles. Size, trim, load and carry on.

As mentioned above, to check for likelihood of future case separation, look for a shiny ring around the case near the case web, second, use a sharp tipped hook type test probe inserted into the case head. If you can feel a groove with the probe inside the case (harbor freight has cheap sets) around the shiny part, that is a case that will probably separate in the future. Another way is to use the old Stony Point (now Hornady) case headspace set. With calipers, it measures your ammo before and after and gives you pretty precise headspace in rimless cartridges. If the case requires excessive resizing then it will probably fail in short order because brass is too stretched to fit the chamber. Necksizing only is called for.

Re scratches, you can polish the chamber but it can make an already generous chamber more so. Scratches in chambers that are deep either require living with it or replacing the barrel for the original caliber.

It could also be a result of dirt or grit in the chamber and action especially if it does not occur on every case. That remedy is simple, run a cleaning patch before shooting and after and keep your ammo clean.

Looks like cases were stepped on while on the ground.

No cleanly ejected and then picked up, sectioned them and then found nothing unusual, hard crud in the chamber wiped right out of the Krag and a little less in the No4. Measured fired cases with the stoney point and nothing unusual there either. In both instances dirt and fouling was at 12:00, thanks for looking.

One of my .303 cases with incomplete head separation note very defined break, as BAR says nothing in the extreme there if you only have one of each rifle then you can get away with neck sizing them as they are fire formed now with then when required Full length sizing.

Full length sizing of cases from the oversize and sloppy chambers of these rifles will eventually get you to the head separation point. It may be two reloads, it may be five. Neck sizing once fired cases should have the longest life. Neck size and use mild cast bullet loads or even mild jacketed bullet loads may even give a longer life. Krag and 303 brass is a low priority for case makers, keep the ones you have for as long as you can.

Dave