Bur in chamber?

[ckaberna]

Ok team, I have a problem I need advice on. Bought a M21 Cooper in a 20VT and all was good with sized/virgin.221 fireball lapua brass, until I fired them. I had “clickers” right off the bat, even with reduced loads. After careful measuring the case just before the neck junction expands.002” when fired. Then extra effort is required to extract the case. All cases have a mark/scratch on them after firing so I put dychem on a fired case and rechambered it. This is the result. Any idea how to fix or what the problem is.
Sized cases do not have the mark/scratch.
You can feel this “scratch” with you fingernail but just barely.

 

[The boogalorian]

Sounds like a job for a teslong.

 

[L.Sherm]

You may be able to polish the area a " little "bit to help.
I saw the same thing on a Cooper 6.5x284 that had a ring in the chamber that made extraction hard also

 

[ckaberna]

Sounds like a job for a teslong.

I have the Lyman but so far haven’t been able to identify any issues?

 

[Mikemci]

I have the Lyman but so far haven’t been able to identify any issues?

I had a Lyman too.
Got a Teslong and it changed my world.

 

[ckaberna]

You may be able to polish the area a " little "bit to help.
I saw the same thing on a Cooper 6.5x284 that had a ring in the chamber that made extraction hard also

Yes that may be a fix. If I could see the issue. I have a 6BR that was chambered for the the rem. Brass that, after advice from a nationally recognized smith, I opened up the rear of the chamber “a bit” to allow for lapua brass and that worked out extremely well. One of the most accurate rifles I have. But that was different than this...??

 

[ckaberna]

I had a Lyman too.
Got a Teslong and it changed my world.

Thanks any model recommended? I would like to use it an IPhone if possible.

Yes that may be a fix. If I could see the issue. I have a 6BR that was chambered for the the rem. Brass that, after advice from a nationally recognized smith, I opened up the rear of the chamber “a bit” to allow for lapua brass and that worked out extremely well. One of the most accurate rifles I have. But that was different than this...??

 

[L.Sherm]

You may be able to rent a neck reamer and have a smith open the neck up a little if all else fails.

 

[SSL]

Thanks any model recommended? I would like to use it an IPhone if possible.

WiFi model. Only one that works with iPhone.

 

[Dusty Stevens]

You need to have the chamber polished by a competent rifle builder. Its not a garage job

 

[232]

I would be willing to bet that if you formed brass from other than Lapua, your click would not be present.

 

[jepp2]

Any idea how to fix or what the problem is.

If the barrel is the Cooper factory chamber job, I would be willing to bet they would correct it for you no charge.

 

[338 dude]

Thanks any model recommended? I would like to use it an IPhone if possible.

I have the flexible Wi-Fi version and it works great with my iPhone

 

[Walt Krafft]

Sounds like the chamber was gouged by a cleaning rod that was used without a bore guide. Like Dusty said, it may be polished out. More than likely it will need to be rechambered deeper.

 

[GAnderson]

The factory chamber on the cooper is right at .232 neck diameter...if you are not turning the necks on your lapua brass, this could be the source of your clickers...a loaded round neck diameter with lapua brass usually measures right at .2315 to .232
This does not address your potential chamber burr issue but I think it will address the clickers.

 

[ckaberna]

The factory chamber on the cooper is right at .232 neck diameter...if you are not turning the necks on your lapua brass, this could be the source of your clickers...a loaded round neck diameter with lapua brass usually measures right at .2315 to .232
This does not address your potential chamber burr issue but I think it will address the clickers.

Yes, the necks are turned to a loaded diameter of .229”. The gouge from a cleaning rod make sense, but this rifle was brand new until I fired it. All the cleaning has been done with bore guide. I am having a tough time believing a brass tip of a cleaning rod could gouge stainless? I suppose anything is possible. Thanks all, I will call Cooper tomorrow.

 

[Alguapo]

Agree with jepp2. Contact Cooper , last time I talked to them a barrel replace would cost about $150.

 

[Bill K]

Call Cooper, talk too them and go with what they advise. They just may well take that one back, check it out and correct any problem and it will be done right.

 

[SmokinJoe]

I would contact Cooper for guidance, but most likely they will just say send it in. Anything else you do may void your warranty.

 

[GAnderson]

Yes, the necks are turned to a loaded diameter of .229”. The gouge from a cleaning rod make sense, but this rifle was brand new until I fired it. All the cleaning has been done with bore guide. I am having a tough time believing a brass tip of a cleaning rod could gouge stainless? I suppose anything is possible. Thanks all, I will call Cooper tomorrow.

Sounds like the best is to do what the above posters have said...let Cooper take care of it.