6BR-AI With BRDX Reamer

[tclaunch]

I used what I had on hand to jump in on Sam Halls inspiring new case. I took a barrel had been chambered and never fired, moved the shoulder .070" and ran my BRDX reamer in to have slight pressure closing the bolt on 6BR go gauge so no galling to worry about. Placed a new 6BR case and measured how much had to be trimmed. A 1.524" OAL is max length. The fired case draws up .007". Sometimes us old timers have too much fun.

 

[Grimstod]

Wish i was retired with this kind of time. Lol

 

[tclaunch]

Here is a fired case to see the BRDX neck length on the BR-AI. Mr Ackley had the right idea to use .004" crush on the less consistent cases of his day, and for sure most AI versions came from cases with low angles. The consistency of Lapua brass, and the combined 30 degree angle was concerning using .004" crush. I used a slight resistance on the BR gauge and all went super. That would be 1/2 to .001" thousands crush.

 

[tclaunch]

Wish i was retired with this kind of time. Lol

I am not retired yet, am between jobs and had time to spin myself a new ride!!!

 

[Eric Leonard]

you may get a box next week with the 8 twist Bartlien that came with my Farley action and my BRDX die,,I really like that case,,

 

[Gabe22BR]

got a pic of this one next to your T 40?

 

[tclaunch]

got a pic of this one next to your T 40?

Not yet....lol. It can be done...!

Here you go Gabe: Dasher, TAC40 and the new TAC Shawty

 

[tclaunch]

you may get a box next week with the 8 twist Bartlien that came with my Farley action and my BRDX die,,I really like that case,,

It must be inherently accurate, I didn't get James' results, but it's been a long time since I've seen fire forming groups as consistently wadded up.

 

[Eric Leonard]

I got busy with yard work and didnt get to it but that would be an awesome round for that old 40X I have,,I got to get around to getting that bbl off and see what we got to work with,,setup for the 87-95 VLDs I bet it would be a killer round for the 400 yard ballons,,

 

[tclaunch]

The freebore is .138

I got busy with yard work and didnt get to it but that would be an awesome round for that old 40X I have,,I got to get around to getting that bbl off and see what we got to work with,,setup for the 87-95 VLDs I bet it would be a killer round for the 400 yard ballons,,

The freebore is .138 on my BRDX reamer, same as you have now. The way yours and junebugs shoots is another reason I wanted to go this route. We know the front end on that reamer is all good.

 

[Eric Leonard]

that freebore is perfect for the 105 class bullets but with that neck length I bet you could load bullets like the 75 VMax and 80 NBT and still reach the lands,,

I bet it would really cook with a zero freebore 14 twist also,,a 9 twist 22 caliber on the same case would be a blast to shoot also,,man I wish I had one of everything,,LOL

 

[Phil]

Tim,

Just jamb the bullet and fire form????

Phil.

 

[Eric Leonard]

I think it is just a crush fit and no need to jam bullets or use a false shoulder or anything,,I dont think he is blowing the shoulder forward at all only changing the shoulder from 30 to 40*

 

[JamesnTN]

Tim,

Just jamb the bullet and fire form????

Phil.

It's a crush fit load it and shoot it. No need to jam any bullet.

 

[Phil]

James,

I was under the impression that it had the BRDX neck length, would`t that necessitate a jamb or false shoulder.

The line that says that it has a BRDX neck length threw me.....

I probably read and interpreted Tim`s post incorrectly from the onset.........

I think i`m following it correctly now, i like this idea, but for my purposes a shorter freebore would be necessary.


Phil.

 

[JamesnTN]

James,

I was under the impression that it had the BRDX neck length, would`t that necessitate a jamb or false shoulder.

The line that says that it has a BRDX neck length threw me.....

I probably read and interpreted Tim`s post incorrectly from the onset.........

I think i`m following it correctly now, i like this idea, but for my purposes a shorter freebore would be necessary.


Phil.

Tim would be more suited to answer since he fire formed a case. But to my understanding he went with a .002 crush fit instead of a .004 so he is still able to not jam his bullets during fireforming.

 

[tclaunch]

James,

I was under the impression that it had the BRDX neck length, would`t that necessitate a jamb or false shoulder.

The line that says that it has a BRDX neck length threw me.....

I probably read and interpreted Tim`s post incorrectly from the onset.........

I think i`m following it correctly now, i like this idea, but for my purposes a shorter freebore would be necessary.


Phil.

Hey Phil, yes I used a BRDX reamer so I would have that neck length, but used a 6BR headspace gauge. I knew this would cause a shorter OAL, but is exactly what I wanted. It is a 6BR improved with a BRDX neck. Trim OAL to 1.514" gives .010" clearance. I first trimmed to max length of 1.524" and upon firing the cases shrunk .006" to .007". Turned out a very easy to look at case.

I initially had .004" crush, and had the option of using my 6BR FL die to reduce crush, so I bumped the shoulder of a new piece of 6BR brass back till it fit the chamber perfectly to my liking, then using a bump gauge from a barrel stub, I compared this fit to the factory case and it was .004" difference. I put the barrel back in the lathe and took the reamer in another .0035" on the Lambeth/Kiff micrometer stop. I now get slight bolt pressure on closing the bolt on a new case. No worry about galling, and all 40 pieces fired beautifully. I was jumping 108`s .020" and never missed a beat. This reamer has a tapered neck from .271" at mouth to .272" at shoulder so I cleaned up with light turn of .0122" to give .003" total clearance, with .266" bushing I get .002" tension. NOW, if I can just figure out how to get it to shoot like James`and Sams barrel!!!!! Its a Bartlein .237" 4 groove 8 twist. It is liking N-203B at first glance.

 

[Phil]

Tim,

That case is definitely easy on the eyes.......


Phil.

 

[tclaunch]

I got busy with yard work and didnt get to it but that would be an awesome round for that old 40X I have,,I got to get around to getting that bbl off and see what we got to work with,,setup for the 87-95 VLDs I bet it would be a killer round for the 400 yard ballons,,

that freebore is perfect for the 105 class bullets but with that neck length I bet you could load bullets like the 75 VMax and 80 NBT and still reach the lands,,

I bet it would really cook with a zero freebore 14 twist also,,a 9 twist 22 caliber on the same case would be a blast to shoot also,,man I wish I had one of everything,,LOL

Been thinking mr.big. The 6BR with zero freebore reamer is shipping, that was a $71.00 work order with JGS. I can use that with my shortest freebore Dasher reamer and fix you up, pretty dang sure. The OAL will be less than 1.565" because of the longer angle of the BR shoulder.

 

[tclaunch]

Just finished the final step. I ordered 2 Harrels Dasher dies to check fit, and took .145" off this morning. It bumps the shoulder just fine.