6mm br help

[6mm06guy]

I just finished building a new 6mm br norma. But I'm running into some problems. It's a tight chamber, 1-8 twist with a 28" barrel.

I built this with the intent to shoot vermin and up to white tail I side 600 yards.
So here is the problem, all the load data you see online shows 28-31 grains of powder for the 105 bergers. I'm getting stiff bolt at 26 grains of varget.

 

[dustbag]

Do necks need to be turned? What velocity are you getting?

 

[K.E.C. Darkside]

What dustbag said.
Do you have the spec for the reamer.

 

[6mm06guy]

Do necks need to be turned? What velocity are you getting?

Unfortunately I haven't gotten my new magneto speed to pick up a velocity yet. I'll try to get some tomorrow

 

[Critter Picker]

Can you slide a bullet into the neck of a fired case? Is there a shiny mark on the top of the neck?

 

[Critter Picker]

I had that issue with mine. I was jamming the bullet. Color a bullet with a sharpie and chamber it. See if there are rifling marks on the bullet.

 

[6mm06guy]

I had that issue with mine. I was jamming the bullet. Color a bullet with a sharpie and chamber it. See if there are rifling marks on the bullet.

I'm off the lands, unfortunately I can't get a bullet into a fired case, but I don't believe it's due to a tight neck/chamber. Every case comes out of the gun with a bent neck due to the extractor.

 

[Critter Picker]

Then you're back to what KEC said. You have to get the reamer specs or try to get a ball end Mike into the neck to measure it. OR remove plunger so neck doesn't distort. That's a tough one. You could make a chamber cast.

 

[6mm06guy]

I think I may have just been too low on powder, I stepped up the powder charge against my better judgment, and the ejector marks went away

 

[Hardshot]

I think I may have just been too low on powder, I stepped up the powder charge against my better judgment, and the ejector marks went away

I have many variations of the 6BR Norma and from what I'm hearing you definitely want to true , cut down your necks . A bullet should fall into a fired case . 30.-30.6 is a very common load with varget and 105 Berger's

 

[6mm06guy]

I have many variations of the 6BR Norma and from what I'm hearing you definitely want to true , cut down your necks . A bullet should fall into a fired case . 30.-30.6 is a very common load with varget and 105 Berger's

Trueing the necks doesn't keep them from bending tho, deforming the neck to not accept the bullet

 

[amu_shooter]

I have many variations of the 6BR Norma and from what I'm hearing you definitely want to true , cut down your necks . A bullet should fall into a fired case . 30.-30.6 is a very common load with varget and 105 Berger's

+1. I run 30.1 to 30.4 of Varget on all 3 of my 6BR barrels with a no turn neck chamber with 105 Berger VLDs. I stay at .008 off lands and move forward as throat wears.

Using Norma Brass as well.

 

[dustbag]

Possible chamber was dirty/oily would cause pressure signs too and lower charges if now it went away.
Glad it's better anyway.