6 mm BR outside neck size

[Rem Jim]

I just bought an old REM 40 X rifle today with a replacement barrel on it chambered in 6 mm BR with a .266 NK size .

Was this common in the OLD days ?

Thxs for any Help

 

[rwj]

Certainly not uncommon not that long ago…

 

[Liven The Dream]

I have a Newer 6BR .270 neck ?

 

[dc.fireman]

I just bought an old REM 40 X rifle today with a replacement barrel on it chambered in 6 mm BR with a .266 NK size .

Was this common in the OLD days ?

Thxs for any Help

That's the size of my current Swiss import model from the early 2010's.

 

[Fire Dog]

I just bought an old REM 40 X rifle today with a replacement barrel on it chambered in 6 mm BR with a .266 NK size .

Was this common in the OLD days ?

Thxs for any Help

If the barrel is good just take a turn or two off and re-chamber with a JGS No Neck Turn 6BR reamer for a .272” neck…. Makes life easy and will shoot well.

 

[Murray Brook]

My Manson reamer has a .2725 neck and works great with Lapua brass. End up with appx .0035 clearance.

 

[Fire Dog]

Murray Brook, here is your byline quote as I heard it and tagline it myself…
The Now More Than Ever part I added….
Now, More Than Ever...
"Those who would give up essential liberty
To purchase a little temporary safety
Deserve neither liberty nor safety."
- Benjamin Franklin -

 

[NZ_Fclass]

I gather that the smaller diameter was to allow necks to be turned to control neck concentricity. Better brass, Lapua, Alpha, etc has removed the issue. I run 269 on the BR and Dasher with Alpha brass and, I think 271 on the BRX with Norma or Lapua.

Just been prepping some new Alpha Dasher - had to expand all the necks with a .243 mandrel so I could size them with a 269 bushing. I have .0015 tension on 107's. Sweet.

 

[kochie]

I gather that the smaller diameter was to allow necks to be turned to control neck concentricity. Better brass, Lapua, Alpha, etc has removed the issue. I run 269 on the BR and Dasher with Alpha brass and, I think 271 on the BRX with Norma or Lapua.

Just been prepping some new Alpha Dasher - had to expand all the necks with a .243 mandrel so I could size them with a 269 bushing. I have .0015 tension on 107's. Sweet.

.269

 

[Fire Dog]

I gather that the smaller diameter was to allow necks to be turned to control neck concentricity. Better brass, Lapua, Alpha, etc has removed the issue. I run 269 on the BR and Dasher with Alpha brass and, I think 271 on the BRX with Norma or Lapua.

Just been prepping some new Alpha Dasher - had to expand all the necks with a .243 mandrel so I could size them with a 269 bushing. I have .0015 tension on 107's. Sweet.

The Sierra 107’s are my “Go To” at the moment as well… Just love the performance of the newer factory “Pointed” ones… the older ones were good but the new ones that I have come back to after moving away to 103’s for a while are just X magnets….

 

[AlNyhus]

That chamber may be for the original BR 1.520 case length, too. Check it to be sure.

 

[Brew2]

I just bought an old REM 40 X rifle today with a replacement barrel on it chambered in 6 mm BR with a .266 NK size .

Was this common in the OLD days ?

Thxs for any Help

My barrel was chambered at .271 and allows for minimal if any neck sizing. Im sure I will get to it though.

 

[expiper]

That chamber may be for the original BR 1.520 case length, too. Check it to be sure.

Pay close attention to response number 11----al is correct it's probably the old Remington style chamber not only is it short in overall length at inch 520 it is smaller at the 200 line and Lapua brass even when shortened will have great difficulty chambering in that tighter diameter chamber--if this is the case, just run a Norma Lapua sized reamer in the existing chamber and open the web up to the correct size and also get the neck opened to around 271

 

[AlNyhus]

Pay close attention to response number 11----al is correct it's probably the old Remington style chamber not only is it short in overall length at inch 520 it is smaller at the 200 line and Lapua brass even when shortened will have great difficulty chambering in that tighter diameter chamber--if this is the case, just run a Norma Lapua sized reamer in the existing chamber and open the web up to the correct size and also get the neck opened to around 271

If it's the original 1.520 long Remington chamber, another option is to use Peterson 7BR brass. It's made to the original BR case length and body dimensions...the back end runs about .003 smaller than Lapua. Neck it down, turn the necks and you're good to go.

Hope all is well with you. -Al