new chamber

L

Liseo

Member
Guys

I have a problem and need your help.

After 1600 rounds fired I decide set back the chamber of my 6 PPC.
I bought a reamer from PTG with a complete set of bushings. My gunsmith cut off the old thread and redo the threads and chamber with care, using the tighter bushing( .2368" as the .2370 dont entered the bore).
After the gun ready, I assembled some rounds to discover the jam lenght.
The problem is that beside the four lands marks I see a continuous semicircle in 3/8 lof the bullet circunference as if the bullet was out of center, touching more one side of the barrel.:eek: As the bushing fit was so tight, seens to me that is not due to backlash. Its possible that the lands are lower on one side than other? The barrel is Krieger

What are your opinions? I an confused with this and any help is welcome.:)

Hope you understand , as english isn´t my mother tongue.

Liseo
 
RE: New chamber

Know anybody with a bore scope? That would be worth a look. nhk
 
New Chamber

This may not amount to anything. I've seen this from new chambers before and it was never due to an out of concentricity chamber. More likely just coming from a sharp edge at the chamber mouth during chambering or extraction. Ir your bolt has a plunger ejector it may be applying side pressure which causes the case to cock as it is pulled from the chamber.

Look at it with a borescope to be sure, but if it shoots, I wouldn't worry.

Scott Roeder
 
I agree

A look with a borescope is a wise idea. You might also check that
your dies are assembling a straight round. In the event that you have
added new cases, they may not be straight yet.
 
Guys

Here in my country, even a BR rifle is a stranger animal, let alone a borescope:eek:

The cases are the same that was used before, but the plunger ejector can be the problem, as ther springs is strong( good tip Scott) I did not think of that before.
Anyway, the first groups are in the .25 to .35 MOA, before load adjustment.

I will remove the ejector and report back the results.

Thank you fellas.
 
Liseo, you may be worrying about nothing. If you're getting .25" groups with no load work, you may not be too far off of your load. Load workup isn't quite the same as if it would have been with a new barrel. I'd expect the same load that shot previously to work in the new chambering. Since it was rechambered with a different reamer from what the barrel was chambered originally it may need to have some changes in seating depth for reamer variation from one reamer to the next. Also, there could be some body dimension variations as well and that might have some effect on the load as well as vibration differences due to a shorter barrel.

I look at my chambers with a borescope after reaming to make sure that the leade length appears to be the same from one land to the next. If the barrel doesn't shoot, then you've lost nothing but time or whatever he charged to rechamber your barrel and the experience will help him when he chambers the next new barrel for you if you can get one imported.

The ejector plunger spring on a Bat isn't as heavy a spring as what is on a Remington. I doubt if that is the problem. If you do remove the ejector, make sure to get it reinstalled the same way that it came out as there may be some difference in length on the cutout for the crosspin. It may not work correctly if you get the ejector pin installed upside down.

One barrel maker that I've talked to about exporting says to put in for an export permit of 49 barrels whether you get one barrel or 49. That way you are covered on the cost for the export permit whether you order one or all 49. They can send you one, ten or 49 on the same export permit.
 
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Hello Mike, glad to hear you.

This rifle is what you assemble for me at the end of 2006. I still have the second barrel untouched, but want to make the most of the first before installing the spare. After verifying the spring, I realized that isn´t strong as i thought.
But the uneven markings bother me. If I redo the chamber, there is possibility that they dissapear?
When i import a new barrel, I will send it to a experienced gunsmith before sending to Brazil;)
 
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