Need a base measurement / 6 BR

[TackDriv3r]

I have 200 pieces of fired Lapua brass from two different chambers, 170 pieces from Chamber A and 30 pieces was fired from Chamber B that I had hard bolt lift before getting a new 3rd 6 BR chamber. I have resized all brass, tried the 130 pieces in the chamber and chambered fine . Shot and fireformed 130 pieces with no issues to my new chamber, sized 70 pieces I had left and 40 pieces of those was from Chamber A and the other 30 from Chamber B. The 30 pieces was so tight in the chamber, whilst the other 40 was fine. I just measured headspace, all is good and I found out that the base of the 30 pieces ( Chamber B ) is .471 -.4715 while the rest from Chamber A is at .470 . What are the specs for the base of the 6 BR Lapua brass? Fired brass measures .470 on the 130 pieces. So I pulled all bullets from the 30 pieces of brass and resized again with a 6 BR full size bushing die, the base still measures at .471-.4715, so I got out a .308 body die ( don't have a 6 BR body die ) and ran the brass through it to try to put it back to .470", but managed only .4705" at best, then ran them through a 6 BR full size bushing die again because headspace grew .002-.003" after running the 30 pieces through the 308 body die. I chambered all the 30 sized cases and they do chamber now, but a little sticky on extraction because of the oversized base. I can see little scratches around the base on the very bottom part of the case. It's where the issue is. What can I do? Do you have the specs on the base of the 6 BR?

 

[2dogs]

I’m having the same issue, I will be following this thread to hear what the mad scientists on here have to say….

 

[rwj]

The current version is the 6BR Norma which is a CIP (European) standard… drawing attached.

 

[Walt Krafft]

Small base 308 die might help. The scrap bucket will work too.

 

[Bob3700]

Years ago I purchased Norma 6XC brass. Turned out the base was a bit too large for my chamber, click on bolt lift when fired.
Could not size the base ( used 308 SB die) of the cases down to eliminate the clicks. Finally gave the bass away.

 

[joshb]

Yup. That’s why I have a 308 small base die on hand. I actually bought it by mistake, then found a use for it with my oversized 6br bases.
Maybe Bob got a bigger SB die. Mine works great and puts it back to .470.

 

[TackDriv3r]

I went back to the loading bench and ran the 30 pieces back in the 308 body die again, on the downstroke I held it in place for 5 seconds before releasing it out of the die, resized again with the 6 BR bushing die. Chambered each piece and it seems to chamber a little better, but some feels a little sticky on extraction, but not much.
Should I get a small base 6 BR body die or a small base 6 BR full size bushing die? Better safe than sorry. Thanks for advice guys

 

[jackieschmidt]

Here is a brand new Lapua 6BR Norma case.

 

[Fast14riot]

I have a 45acp die I gutted and use as a sort of ring die for my 6br and 308/06 based cartridges. I also have a custom straight wall die .001" smaller that I use from time to time on brass that was fired in an oversized chamber with a stout load.

 

[Chris Edmondson]

I measured a few of my fired Lapua 6BR Norma cases, all mic .4707 at the base.

 

[hoz53]

I have 200 pieces of fired Lapua brass from two different chambers, 170 pieces from Chamber A and 30 pieces was fired from Chamber B that I had hard bolt lift before getting a new 3rd 6 BR chamber. I have resized all brass, tried the 130 pieces in the chamber and chambered fine . Shot and fireformed 130 pieces with no issues to my new chamber, sized 70 pieces I had left and 40 pieces of those was from Chamber A and the other 30 from Chamber B. The 30 pieces was so tight in the chamber, whilst the other 40 was fine. I just measured headspace, all is good and I found out that the base of the 30 pieces ( Chamber B ) is .471 -.4715 while the rest from Chamber A is at .470 . What are the specs for the base of the 6 BR Lapua brass? Fired brass measures .470 on the 130 pieces. So I pulled all bullets from the 30 pieces of brass and resized again with a 6 BR full size bushing die, the base still measures at .471-.4715, so I got out a .308 body die ( don't have a 6 BR body die ) and ran the brass through it to try to put it back to .470", but managed only .4705" at best, then ran them through a 6 BR full size bushing die again because headspace grew .002-.003" after running the 30 pieces through the 308 body die. I chambered all the 30 sized cases and they do chamber now, but a little sticky on extraction because of the oversized base. I can see little scratches around the base on the very bottom part of the case. It's where the issue is. What can I do? Do you have the specs on the base of the 6 BR?

ive had this issue it my 6bRs at times. like Fast says for me it was basicaly clickers. i found a 243 size die without much chamfer and it works sometimes. what we really need is a ring die to size the base back down.

 

[Murray Brook]

Keep in mind that brass has a memory and if fired too many times in a larger chamber they may still give you problems even sized down with a ring die or small base die.

 

[pilediver]

I bought a Lee carbide 45 acp die, it will resize the base of those cases.

 

[Link]

Why don't all smiths use a different reamer at the .200? Isn't the RG 30 BR reamer print like .0005 different?

 

[rwj]

This is a recommendation to buy a set of Harrell’s 6BR dies that are available in incremental sizes to address base sizing. I bought all sizes and now never worry about what reamer (mine or a smith’s) was used to form the chamber.

 

[jds holler]

My 22 BR Rem chamber gave me trouble with Lapua, and I did the small base 308 thing - one time. After that, no more problem even with subsequent loadings. jd

 

[Link]

This is a recommendation to buy a set of Harrell’s 6BR dies that are available in incremental sizes to address base sizing. I bought all sizes and now never worry about what reamer (mine or a smith’s) was used to form the chamber.

Let me ask, how many dies, at what cost?

 

[rwj]

Let me ask, how many dies, at what cost?

Full Length Die

For the best fit on Full Size Die - please call (540) 380-2683 Hardened stainless steel .002 undersized for easy chambering. Can be cut to length for short chambers. Comes in PPC, BR Remington, 6.5 x 47 and Dasher.

www.harrellsprecision.com