Help with very difficult extraction

[FURMAN]

Just got my 20br together and finally had a chance to shoot it. It is very difficult to extract fired cases. Even at 28.5gr Varget under a 55gr Berger it is more difficult than I have ever felt. Todd Kindler told me this is a very very weak load so it should not be a pressure issue. Sized cases cycle fine. The only measurement I see a difference between sized and fired cases is about .002-.003 shoulder bump and the neck goes from .233 to .235 in a .236 chamber. I am at a loss.

 

[medicineman]

Don't pay any attention to what Todd said, you have a pressure problem. It could just be a hot lot of powder. I would check velocities on a chronograph and compare to acceptable pressure data. Every barrel has a personality of it's own, it may not like the combination you are feeding it.

 

[AlNyhus]

What action are you using?

 

[FURMAN]

It is a Savage target action. Problem still exists at 3440fps which is pathetically slow. If this is how it is going to be I am going to sell it or part it out and build something else. This is not acceptable.

 

[AlNyhus]

Is this the first barrel you've had on the action?

 

[FURMAN]

Yes. I had Sharp Shooter Supply time and true the action and install the trigger and barrel.

 

[Preacher]

Check out the chamber with a casting of Cerrosafe......... that will show any problems in that area..
How does the brass look when it's extracted ?

 

[FURMAN]

The brass is scuffed up more than I think it should be.

 

[Preacher]

Circular marks on the brass, or running the long way ?
Either way if you polish the chamber it may go away....
400 grit to start, finish with 600, or close to it.....

 

[FURMAN]

Lengthwise. What do I use to polish it?

 

[Preacher]

I would have thought they would be circular, but any marks should be removed..
A short piece of dowel rod the shape of the chamber as close as you can get it, split so it will hold a piece of wet-dry 400 grit paper oiled up good and spin it in the chamber very carefully.... keep it oiled up good... A few minutes should have it ready for 600 grit, keep that oiled good too. Clean the chamber with alcohol real good and see if it helped when you shoot it again...

 

[FURMAN]

I will try it. Thanks.

 

[AlNyhus]

You may want to verify how much primary extraction you're getting before you start polishing the chamber. -Al

 

[Preacher]

If it has been leaving marks on the brass it still needs to be polished so it don't.

 

[largemouth1]

Try Flitz on your chaimber per Varmint Al's instruction. Go to his web site

 

[FURMAN]

It is on its way back from Sharp Shooter Supply. He polished the chamber and the dies. I will report back when I shoot it.

 

[FURMAN]

Sent the rifle back to Fred at Sharp Shooter Supply. He said the chamber was scratched up. Polished the chamber and dies. He said it did not show any increased bolt lift effort until 32.0 grains of Varget. I got it back today and the problem is in fact fixed. Thanks for all the help.