Cause of brass damage?

[jebbh]

Sorting through some old cases and noticed one of my rifles was damaging the brass during ejection.
brass..jpg
click to enlarge

Anybody know the cause/cure?
Thnaks, Jebb

[snakehunter]

I've got a '95 Winchester 30-06 that does the same thing. Never could figure out why. I hope somebody here can shed light on the problem.

[bd1]

OP, you're shooting a Garand, right? Empties bounce off the op rod upon ejection and get beat up. It's normal.

[joem]

If you reload them they will size correctly and the dents will be gone.

[JimF]

I've got a '95 Winchester 30-06 that does the same thing. Never could figure out why. I hope somebody here can shed light on the problem.

Winchesters that eject out the top are prone to do this.
The cases hit the small cut-out in the barrel (where the front tip of the extractor nestles) and acquire this dent.
Just for "sh*ts and giggles", chamber an empty and SLOWLY extract while maintaining DOWNWARD pressure on the side of the case as it comes out.
Notice how there will be NO dent in the case mouth because your finger never allowed the mouth to contact this tiny notch at 12 o'clock in the barrel. --Jim

[jebbh]

It is curious that some M1 rifles (most that I own) don't dent brass, but one of them does. Perhaps it's a function of op rod spring strength?

[BudT]

As the case is ejected it hits the top of the barrel/receiver on the way out. My 95 in 30-40 Krag does the same thing. Something else you may or may not of noticed on ejection, you hear a slight whistling sound, that's from the case.

[Sunray]

It's just how the rifle works. Cases whack the receiver/op rod on the way out. The fix is a needle nosed plier used as a reamer to open the cases mouth just enough for the expander to fit. Nothing done to the rifle.

[PhillipM]

A common center punch is all I use.

[flintsghost]

It is curious that some M1 rifles (most that I own) don't dent brass, but one of them does. Perhaps it's a function of op rod spring strength?

The fact that some don't dent brass is because their op rod spring is closer to new spec and the one that does has a spring that has taken a set and is slightly below spec. The same can be said of both the ejector spring and the extractor detent spring. Try a "new" replacement spring in the one that does and see if it stops. It probably will. If you want to go a step farther...install a new ejector spring and then find the shortest extractor detent spring that you can in your parts box and install them. That will give the fastest ejection and the extractor will have the lightest hold on the case rim. However, it will start up again as the op rod spring begins to wear and the others wear in. The other variable is the load. If you are shooting reloaded rounds that will make a difference. If you always shoot a factory or GI issue round you will remove that variable. For example on my NM M1A when I shoot Federal GMM 168 grain, it will stack the brass in a neat little pile next to the bench I'm shooting from. With my other non-match M1A shooting M59 or M80 ball it will throw brass all over the range area in all directions. Both use GI Op rod springs that were installed at the same time. As long as the ejection is consistent, I don't worry much about the springs in the bolt.

[Dan Shapiro]

A properly timed M1 will cause a 'D' shaped dent in the case mouth. Slow motion video shows that upon extraction, the case is flipped 180 degrees; on moving forward, back into battery, the hump of the op rod strikes the falling case, knocking it out to about 2 o'clock.

[musketshooter]

The ejector spring is to strong. Take a coil off it and try it. Cut more if necessary, about a half coil at a time.

[UUURah]

The ejector spring is to strong. Take a coil off it and try it. Cut more if necessary, about a half coil at a time.

I think it's all in the ejector spring. I recall....

When I first assembled my .308 Garand, it would throw the cases TWENTY FEET to the right. It was something to see, they would fly. Of course that was unmanageable, especially in a Match. Taking a cue from someone here, Gus I think, he said take a "loop" out of the ejector spring, try it, then another.

With the removal of the 2nd loop, it started dropping the cases in a neat pile 3 feet to the right.

Ahhhh ... The M1 Garand. Truly the "finest battle implement ever devised".

[ltcboy]

A common center punch is all I use.

Wouldnt your resizing die do this?

[Liam]

I've had my sizing die bend over the edge on badly dented case mouths. I do as PhillipM does - although I use an old screwdriver. When it looks fairly round, I then resize.