Browning BAR bolt will not close on round

[merbeau]

I have recently purchased an older Browning BAR in 7mm Remington Magnum. I purchased some 1x fired Barnes 7mm Rem Mag brass and trimmed the brass to 2.485 inches before running them through a RCBS X FL die.

After FL sizing I took a 150 grain Nosler Long Range Accubond bullet and seated it so it would fit into the magazine.

When I took that round a tried to chamber it, the bolt would not close fully. I then proceeded to seat the bullet deeper and deeper into the brass with the same result. I tried this on a three other pieces of brass with the same result for two with the third closing.

I then pulled the bullet placed a primer into the case, made a mild load with
IMR 4350 and reseated the bullet. The round chambered and fired with the case ejecting.

I thought originally the bullet was seated to far out, but does not seem to be the issue.

Do I need to purchase a small base die?

I have ordered some factory ammo to test to see if it the same problem occurs.

Thanks

Robert

 

[NoFences]

A small base sizing die is needed for reliable feeding.I got one from RCBS

 

[merbeau]

Ok, thanks for the replay and information. I just placed an order for the small base die from RDBS.

Thanks

Robert

 

[barefooter56]

Ok, thanks for the replay and information. I just placed an order for the small base die from RDBS.

Thanks

Robert

Especially if you are using once fire brass out of another rifle ! I would suggest new brass and dedicate it to that rifle to make life easier. The small base die MAY fix your issue but that will depend on where your problem is. Is it the down at the base of the cartridge case body or is it the shoulder not being bumped back far enough ? If you have another piece of brass that chambers and you have a set of calipers and a Sinclair or Hornady bump gage kit. Measure the base to datum line on shoulder of the case that fits and one that does not fit along with the case body diameters one of those two or both MAY need to be addressed. The small base die only may address the case body issue and not the shoulder. Check. An L. E. Wilson cartridge case gauge will help also. Sinclair has them.

 

[merbeau]

Great points! I will keep that in mind after seeing if the small base die works.

Robert

 

[merbeau]

Especially if you are using once fire brass out of another rifle ! I would suggest new brass and dedicate it to that rifle to make life easier. The small base die MAY fix your issue but that will depend on where your problem is. Is it the down at the base of the cartridge case body or is it the shoulder not being bumped back far enough ? If you have another piece of brass that chambers and you have a set of calipers and a Sinclair or Hornady bump gage kit. Measure the base to datum line on shoulder of the case that fits and one that does not fit along with the case body diameters one of those two or both MAY need to be addressed. The small base die only may address the case body issue and not the shoulder. Check. An L. E. Wilson cartridge case gauge will help also. Sinclair has them.

Update. Thanks to all that replied. Well the small base die came in and I had the same problem. So I purchased an L.E. Wilson gauge and it appears the shoulder was not set back far enough. Went back to my RCBS X die instructions and after some reading finally deciphered how to set the shoulder back. After following what they suggested (i.e., remove the mandrel and then adjust the die downward and then replace the mandrel) the round fit the Wilson gauge and I was able to insert a resized case into the chamber, close the bolt and have it function (i.e., eject). Same thing with a dummy round with only bullet seated. Finally made some live rounds and went to the range and the rifle cycled fine. The brass grew an additional 0.002 after all this but RCBS indicates this may occur. So now back to finding a load.

 

[Wagmaster]

In your original post you stated that you trimmed to length, then resized the brass.

I full length resize, then trim, that way nothing changes by the resizing process

Take care John C

 

[MudRunner2005]

A small base sizing die is needed for reliable feeding.I got one from RCBS

This is a good thing to check.

He also needs to check the headspacing... The brass was fired from a different chamber, therefore, the headspace might not be 100% spot-on. He might need to push the shoulder back a couple thousandths for the case to fit.

 

[merbeau]

Wagmaster

Typically I trim after resizing too but RCBS for their X die wants to have all the brass the same length before sizing, that way supposedly the die will keep all brass consistent over time.

Robert

 

[merbeau]

This is a good thing to check.

He also needs to check the headspacing... The brass was fired from a different chamber, therefore, the headspace might not be 100% spot-on. He might need to push the shoulder back a couple thousandths for the case to fit.

Posted in another person's response. Update. Thanks to all that replied. Well the small base die came in and I had the same problem. So I purchased an L.E. Wilson gauge and it appears the shoulder was not set back far enough. Went back to my RCBS X die instructions and after some reading finally deciphered how to set the shoulder back. After following what they suggested (i.e., remove the mandrel and then adjust the die downward and then replace the mandrel) the round fit the Wilson gauge and I was able to insert a resized case into the chamber, close the bolt and have it function (i.e., eject). Same thing with a dummy round with only bullet seated. Finally made some live rounds and went to the range and the rifle cycled fine. The brass grew an additional 0.002 after all this but RCBS indicates this may occur. So now back to finding a load.

 

[MudRunner2005]

Posted in another person's response. Update. Thanks to all that replied. Well the small base die came in and I had the same problem. So I purchased an L.E. Wilson gauge and it appears the shoulder was not set back far enough. Went back to my RCBS X die instructions and after some reading finally deciphered how to set the shoulder back. After following what they suggested (i.e., remove the mandrel and then adjust the die downward and then replace the mandrel) the round fit the Wilson gauge and I was able to insert a resized case into the chamber, close the bolt and have it function (i.e., eject). Same thing with a dummy round with only bullet seated. Finally made some live rounds and went to the range and the rifle cycled fine. The brass grew an additional 0.002 after all this but RCBS indicates this may occur. So now back to finding a load.

Good deal. Now you've got brass formed for YOUR chamber. You should be able to normal full-length size your brass now that the headspacing and case shape is formed to your chamber.