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6mm br help

6mm06guy

Well-Known Member
Joined
Mar 2, 2015
Messages
432
Location
Missouri
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.
 
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 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.
 
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.
 
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 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
 
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
 
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.
 
Possible chamber was dirty/oily would cause pressure signs too and lower charges if now it went away.
Glad it's better anyway. 👍
I believe the low powder charge wasn't properly expanding the brass and causing the brass to "slap" the back of the bolt, causing a false ejector plunger mark
 

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