cases are from a model 100 win. in .243.100 gr.pills from sierra,speer. powder charges are imr 4064 32.0;imr 4320 34.0;imr 4350 37.0;H-380 34.0.I found brass "flakes" on the bench during my shooting session then noticed the "c" shapes on the cases.Is this a pressure sign or a mechanical (i.e.gun)problem?I know it isn't the dies.couldn't find any thing about this in the archives.Can anyone help me see the light before it finds me?I am somewhat concerned because I don't understand what these marks mean

Ill bet they are close to your bullet diameter that came from the inside of the case neck.
They are stuck inside of your chamber wall and can be hard to remove,good thing is they
wont really hurt any thing. You might try a
.410 bronze brush from the muzzle end to work it loose.It is pretty common,I have seen alot worse looking brass that was shot out of very poorly maintained semi autos.

Are you beveling the inside of your case mouths?

I need to clarify this.the "c" shapes are gouges on the side of the case,near the bottom,not the bits of brass that have been shaved off to cause these gouges.brass bits look like mini corn flakes on the bench.I am gonna try to post a picture.the brass bits are deffinitly not from chamfering.

thanx

I had "sort of" that same problem, quite a few years back!

I was getting the "c shape" with a little curly-Q on it! Noticed it on about 4-5 of my 6mm Remington brass! Checked it out and it turned out to be a bristle from my bronze bore brush, that had pulled loose and must have stuck in the chamber with a small bit of oil!

OK I"ll check for junk in the chamber, although I clean my guns pretty well,stuff happens.what about the cases?are those dings going to cause a problem?They have been reloaded 5 times.Geez,that sounds cheap.I am just gonna get new brass!and try the .410 brush in the chamber.

Hey prplbkrr, How in the world do you pronounce that?

When you are about done for the evening, get yourself a BIG drink of your favorite beverage (tea, milk, etc.) and sit down with the empty rifle across your lap along with a few of those "C-marked" cases.

Have a drink.

Lock open the Bolt and have the barrel pointed to your right.

Have another drink and move the drink to your left side before setting it down.

Hold the Case by the Neck in your right hand so the "C-mark" is pointed toward your left and the back of the rifle. No, not the Case Head, the "C-mark"! The Case Head should be pointed directly at the Ejection Port.

Reach with your left hand and have another drink cause this is the last chance and set it back down.

Ease the Case Head through the Ejection Port so the Casehead is nearly touching the Boltface and see if that mark aligns with the "Left Edge" of the Ejection Port. If it is, then the Case is simply hitting the Ejection Port as it is being Ejected and you can celebrate - with another drink if you have any left.

If it isn't, it might be the old "wire in the chamber" that Chuck mentioned. And if it isn't that, you mights well finish off all the drinks in the house, cause I don't know what it is.
---

By the way, take a Spent Cartridge prior to resizing or de-priming and stick it in your Cleaning Kit. When you go to clean the M100(or any semi-auto) put a Spent Case in the Chamber and close the Bolt before you begin cleaning. Then the vast majority of the trash that "flings' off the brush as it enters the Chamber and snaps open will be tossed into the Spent Case. You still need to clean the Chamber after you remove the Spent Case, but it should be easier for you. Oh yes, pass this tip on to other semi-auto shooters.

I call myself purple biker.I was just to lazy to type in the vowels and double hit the R,back when I wasn't a very fast or patient typist(still not a fast one but more patient now)It does appear that as the empties are flung out of the action they are hitting a portion of the ejection port.I chambered an empty case then slowly opened the action until the case started to eject.Had to have my son help on me. This is a three handed job.Anyway,looks like the case is acting like a hinge on the ejector(extracter?)thank you for the tip Hot Core!I really was concered about this problem.as for the drink,it's hot and I need one.

Hey prplbkrr, Your welcome. The marks "probably" won't cause any problems for you if you only shoot them 5-6 times. Really depends on a lot of things like the strength of your Loads, if it happens to hit the case in the same spot, etc., so I could be off on that statement.

Had a few buddies over the years with M100s, so I've seen that before.

Since case life will be a bit on the short side, I don't know if you want to fool with this next recommendation or not. But, since you have the benefit of a young helper, it might be something you all could do together. We used to re-form military cases for the M100. Most of my buddies had 308Win M100s, so no re-forming was needed, but a few had 358Wins and we would do it for them.

If you want to reduce the necks on some Military Cases to 243Win, I can recommend running them through a 7mm-08 Die first. Just leave the Decapping Stem out of the Die and use some good old Imperial Sizing Die Wax "lightly" on the Necks. Then repeat with the 243Win Die and do an "Anneal".

Huuuummm, wore me out thinking about it. Just buy the regular cases and toss them after 5-6 shots.

I'll just buy new cases.Seems like the best way to go.Thanks again for the tips.I'll sleep better tonight.


prplbkrr