Chambering rounds

[Dalua]

Is this the same rifle from this thread Cleaning the shoulder in the barrel ?
One could perhaps imagine that the force applied to the case-mouth when squashing a round into chamber shortened by crap built up between the mouth of the case and the front of chamber might cause the shoulder to buckle in that interesting manner.

If were the case, the appearance of the fired cases would most likely be unremarkable.

 

[scotch_egg]

Seems like a recurring problem

Cleaning the shoulder in the barrel

when chambering just lately in my 22/250 the bolt is tight to close ,could this be the shoulder might need cleaning not suer if that’s the correct wording .when I do clean the the rifle the brushes dypass that part of the barrel .is the a larger brush that would clean this part of the chamber...

www.thestalkingdirectory.co.uk

Probably should have taken advice on board first time round.

This time listen to what’s been said.

Shooting this ammunition in this state is just dangerous and to be blunt stupid.

 

[Ronin]

Feck

A thread from 2022 POSSIBLY the same rifle

If it is and you did nothing then yet have continued to use the weapon ,,,,

Perhaps consider an alternative hobby

I’m out anyway (if it is the same weapon)

Failed to listen the first time

Darwin rules

 

[Dalua]

Feck

A thread from 2022 POSSIBLY the same rifle

If it is and you did nothing then yet have continued to use the weapon ,,,,

Perhaps consider an alternative hobby

I’m out anyway (if it is the same weapon)

Failed to listen the first time

Darwin rules

To be fair, the OP might well have cleaned his chamber then, as he might now, as advised.

Does it not remain a possibility that these cartridges are at fault, by being too long in the neck?
Or his chamber, by being on the short side? Meaning that when he enounters factory rounds with longer necks he gets an effect ranging from a slightly stiff close to (as here) a close so hard that the result is a buckled shoulder?

 

[VSS]

Feck

A thread from 2022 POSSIBLY the same rifle

If it is and you did nothing then yet have continued to use the weapon ,,,,

Perhaps consider an alternative hobby

I’m out anyway (if it is the same weapon)

Failed to listen the first time

Darwin rules

He may not have used it in the interim, and is now revisiting the problem.

 

[Utectok]

I suspect a carbon ring is pushing the neck back and that’s moving the shoulder easy to identify and remedy (with elbow grease and jb bore paste)

 

[scotch_egg]

I suspect a carbon ring is pushing the neck back and that’s moving the shoulder easy to identify and remedy (with elbow grease and jb bore paste)

Having just scrubbed te carbon ring out of my 7mm SAUM, I struggle to see how the ring can form tight enough to cause such a tight impasse. Spikes in pressure yes, a crush fit on the case no. Carbon ring isn’t a common issue in smaller carriages.

 

[Dalua]

Having just scrubbed te carbon ring out of my 7mm SAUM, I struggle to see how the ring can form tight enough to cause such a tight impasse. Spikes in pressure yes, a crush fit on the case no. Carbon ring isn’t a common issue in smaller carriages.

Is there a risk of confounding two positions for a 'carbon ring'? The one folk often seem to mean is found just into the barrel proper.
I think here we're considering a carbon deposit adjacent to and on the chamber-side of the lip where the chamber's neck meets the lead (or leed, as some have it).
Not something I've come across before, but interesting to think about!

 

[scotch_egg]

Is there a risk of confounding two positions for a 'carbon ring'? The one folk often seem to mean is found just into the barrel proper.
I think here we're considering a carbon deposit adjacent to and on the chamber-side of the lip where the chamber's neck meets the lead (or leed, as some have it).
Not something I've come across before, but interesting to think about!

The true carbon ring is the later you describe. Often missed by the bore brush due to the use of a bore guide and no bullet to abrade it as it falls below the case neck. It builds up preventing the case neck opening to release the bullet in consistent controlled way. The build up goes in waves as the case mouth scrapes it down. The gases of a slow burning powder used in larger cases have the tendency to cause this issue.

See the lead edge which is a silver line to the left. This was my 7mm SAUM.

 

[Heym SR20]

It may also be a function of:

1) A chamber that is cut to minimum tolerances and a cartridge that is closer to maximum. I have noticed in my rifles that some brands of ammo are a little tighter than others. PPU in my 243 is particularly tight, RWS no issue.

2) Plunger ejectors - these can get gunked. As you close the bolt you have to compress the ejector spring. If the plunger / spring is gummed up, or a bit rusty etc then it can get quite a bit to push and close. A push feed with a plunger ejector does need positive forward pressure on the bolt handle to close.

Good service and maintenance is key on all mechanical machines. Ignoring will lead to issues.

 

[Kalahari]

Time for a proper go/nogo gauging. Not an expert but although a visual inspection might show dirt/detritus/corrosion at the neck end of the chamber and also show that it has been cleaned away it might still be a very tight chamber which will make the problem likely to come back.

David

 

[Rural Management Services]

Not sure if iam on the right forum when I chamber a round the bold is really hard to seat down it’s only just started it shoots fine once in but there’s something wrong , I’ve put two rounds in and when ejected there’s definitely some compression marks on the neck of the shell I’ll attach some picture any thoughts please thank you

Bloody hell I wouldn’t be shooting that as you are likely to go full Anne Boleyn before long.

 

[scotch_egg]

It may also be a function of:

1) A chamber that is cut to minimum tolerances and a cartridge that is closer to maximum. I have noticed in my rifles that some brands of ammo are a little tighter than others. PPU in my 243 is particularly tight, RWS no issue.

2) Plunger ejectors - these can get gunked. As you close the bolt you have to compress the ejector spring. If the plunger / spring is gummed up, or a bit rusty etc then it can get quite a bit to push and close. A push feed with a plunger ejector does need positive forward pressure on the bolt handle to close.

Good service and maintenance is key on all mechanical machines. Ignoring will lead to issues.

Valid observation regarding the ejection plunger. Could quite easily be gummed up and would cause this issue on in spec factory ammunition. Enough force to compress enough to get the bolt close and compress the case.

We were all blinkered to a chamber issue.

 

[Dalua]

Valid observation regarding the ejection plunger. Could quite easily be gummed up and would cause this issue on in spec factory ammunition. Enough force to compress enough to get the bolt close and compress the case.

We were all blinkered to a chamber issue

This does look like a very-specific type of case-compression. I can understand how a hard bolt-close bearing on the mouth/lips of the case could buckle the shoulder as in the OP's photo's.
The ejector-plunger being gunked would simply be shortening the headspace - which ought to result on the camming-effort pressing on the meeting-point of the case-body and shoulder. I'm not sure that such an appearance would be the result?

 

[scotch_egg]

This does look like a very-specific type of case-compression. I can understand how a hard bolt-close bearing on the mouth/lips of the case could buckle the shoulder as in the OP's photo's.
The ejector-plunger being gunked would simply be shortening the headspace - which ought to result on the camming-effort pressing on the meeting-point of the case-body and shoulder. I'm not sure that such an appearance would be the result?

Case neck not damaged and the shoulder crumpling and caving in. Definitely looks like the chamber is too short for the cartridge. Created by an ejector plunger not compressing properly.

Seeing the case head. The bottom of the case, just for clarification, would show damage I suspect if this was the case. No pun intended.

As it happens I have a 7-08 round that buckled on chambering with the walls going inside the shoulder. Have no idea what happened as was on the firing line and wasn’t a single load operation. No evidence of damage and the next round went in fine.

 

[Bavarianbrit]

Too tight to get a qualified gunsmith to sort out the cause it seems. Sorry to be so blunt but thats how it seems to me.

 

[DavyG]

Case neck not damaged and the shoulder crumpling and caving in. Definitely looks like the chamber is too short for the cartridge. Created by an ejector plunger not compressing properly.

Seeing the case head. The bottom of the case, just for clarification, would show damage I suspect if this was the case. No pun intended.

As it happens I have a 7-08 round that buckled on chambering with the walls going inside the shoulder. Have no idea what happened as was on the firing line and wasn’t a single load operation. No evidence of damage and the next round went in fine.

Could a jammed ejector cause something similar…?
DG

 

[BE Precision]

It cant be just the ejector, that would push shoulder on shoulder if all other things were good, case would unlikely crumple at that point. I would be looking in front of, or at the crumple location, not behind it. Maybe a combination of both, but not just the ejector. Ammo quality/dimensions is also favourite as a real time variable.

Is this a sudden or gradually emerging issue??

When you hear hoofbeats, think horses, not zebras.

 

[DavyG]

It may also be a function of:

1) A chamber that is cut to minimum tolerances and a cartridge that is closer to maximum. I have noticed in my rifles that some brands of ammo are a little tighter than others. PPU in my 243 is particularly tight, RWS no issue.

2) Plunger ejectors - these can get gunked. As you close the bolt you have to compress the ejector spring. If the plunger / spring is gummed up, or a bit rusty etc then it can get quite a bit to push and close. A push feed with a plunger ejector does need positive forward pressure on the bolt handle to close.

Good service and maintenance is key on all mechanical machines. Ignoring will lead to issues.

Your diagnosis sounds more plausible than my initial thought that someone was trying to chamber a 6.5 Mauser into their Swede…
DG

 

[scotch_egg]

Could a jammed ejector cause something similar…?
DG

Maybe you are thinking extractor, I can’t see that providing enough resistance to not ride over the rim.

Op hasn’t stated if the cases are being ejected properly when extracting the rounds.

With the bollockings I wouldn’t be surprised if they don’t reply out of embarrassment.