Rim on Spent Brass

[ToddDubya]

I took my new Frankenrifle out for a spin this past Friday. I set up at 25m to get the iron sights on target. BANG! Click. Or better yet, no click. I clear the double fed round but cannot get the empty case out of the chamber. I don't have a dowel or anything with me, so my trip is busted after one round.

Fast forward to today. I brought factory ammo instead of reloads. Same thing only I have a dowel. Eventually I get a few rounds in a row, then JAM. My dowel breaks and I'm packing it up again.

Tonight I cleaned the shit out of it, scrubbed the chamber with a chamber brush, and started studying a spent case. There's a little ring around it just behind the shoulder. My other rifle doesn't leave anything like this.

Is this caused by a bad chamber? What's the easiest fix?

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[ToddDubya]

Oh yeah, I can feel it with a fingernail.


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[SJan]

Who made the barrel? Send it back

 

[OfficerObie59]

Chamber looks a little too open. I have this happen with my M1903 Springfield, but in fairness to that gun that barrel was built in December of 1919.

The ring you're seeing is where the powder chamber begins, where the walls of the brass expand against the sides of the chamber. I'm far from an expert, but with tapered rounds, this can happen if there's too much headspace, since the sides of the round don't touch the walls of the chamber.

 

[ToddDubya]

It's not the ring by the rim, it's about 1/16" behind the shoulder. It's almost like there's a lip in the chamber.

The barrel is one of the Stoner barrels from Midway. If it's something I can fix without sending it back (especially since I bought it from someone who never put it to use) I'd much rather do that.


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[OfficerObie59]

It's not the ring by the rim, it's about 1/16" behind the shoulder. It's almost like there's a lip in the chamber.

The barrel is one of the Stoner barrels from Midway. If it's something I can fix without sending it back (especially since I bought it from someone who never put it to use) I'd much rather do that.


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Have you taken a bore light and examined the chamber?

 

[ToddDubya]

Have you taken a bore light and examined the chamber?

I hit it with a flashlight and didn't see anything. A bore light is a reasonable next step; I'll try that tonight.

 

[jtnf]

I thought Eddie Coyle (Jim) said during the basic metallic cartridge reloading class that what you are seeing is case stretch from excessive headspace... Rimless cartridges are forced forward by the firing pin until they seat on the shoulder and then the case stretches radially upon firing, and axially (causing the stretch mark) until the case base meets the bolt face.
Check before and after on a headspace comparitor?

 

[ToddDubya]

I thought Eddie Coyle (Jim) said during the basic metallic cartridge reloading class that what you are seeing is case stretch from excessive headspace... Rimless cartridges are forced forward by the firing pin until they seat on the shoulder and then the case stretches radially upon firing, and axially (causing the stretch mark) until the case base meets the bolt face.
Check before and after on a headspace comparitor?

I checked with Go/No-Go gauges before firing it and it worked/didn't work as expected. I also used dummy rounds that I made (case and bullet, no primer or powder) and it cycled them just fine.

It's not the lines running length-wise, it's the little ring behind the shoulder. You may have to click on the photo to see it full size to see what I'm talking about. It's very faint, but *could* be enough to cause the stoppages. In effect there's the shoulder that's nice and smooth, then a little step up to the straight section of the case.

 

[bsalie]

it might be a case of the reamer used to cut the chamber was past spec. I have had a rifle pass the headspace check, but have a chamber out of spec, Had a smith run a new reamer in the chamber to clean it up and it worked, if it is a new barrel send it back

 

[jtnf]

I checked with Go/No-Go gauges before firing it and it worked/didn't work as expected. I also used dummy rounds that I made (case and bullet, no primer or powder) and it cycled them just fine.

It's not the lines running length-wise, it's the little ring behind the shoulder. You may have to click on the photo to see it full size to see what I'm talking about. It's very faint, but *could* be enough to cause the stoppages. In effect there's the shoulder that's nice and smooth, then a little step up to the straight section of the case.

I see it now. I thought you were talking about the bright shiny band by the base.
You may well be looking at a bad chamber - I am afraid I've got nothing for you. [sad2]