Anybody loading 6mmBRX

[mikeinct]

Question,... can I use my BR modified case to find my seating depth till I get some fired rounds then I can make one. Yes, & Lefty, I made a feeler gauge to set the old 6mmbr die up 100 thou. it was close enough. Then Prime w/ Mag primer. Use a standard 6mmbr powder charge/preferred bullet to fully fire form that case. When fireforming this way you have to jam the bullet some into the rifling. You R going to have fun with this project. Mike in ct

 

[mikeinct]

Hey Lefty, Did you anneal those 4x fired cases ? Mike

 

[tmwinds]

If you have the mandrels and bushings the false shoulder method of fire forming works really well. I used a .264 mandrel to expand the case neck and then used a .267 bushing to size the neck down and create a false shoulder that would close snugly in the chamber. I used a normal 6BR load and the shoulder blew forward perfectly.

 

[Lefty Trigger]

Hey Lefty, Did you anneal those 4x fired cases ? Mike

I have a hundred set aside to run through my Bench source machine. I'm kinda excited about it, I like having the "different" toy at the range and a few club members running Dashers need their asses kicked with something different.

 

[1885Winman4590]

Mine shot quite well with 33.0 of varget, cci primers, and 105 target vld's jammed .005. It was a model 12 savage w/ 30" prefit McGowan barrel. Good luck w/ yours. Brx is a fun caliber once you get your brass formed. I used the seating to jam method. And it worked fine

 

[Bob L.]

33.0 gr. Varget, CCI 450, Berger 108 gr BT Match Target jumped .010. I use the false shoulder method to fire form with 30.0 gr Varget.

 

[Geno C]

Without my notes, off the top of my head,
34.7gr H4350
105vld
450 primers
2925fps

I can’t remember if this one is .010 off or into the lands though

I fireformed with 105amax jammed .005 and a false shoulder. 29.4gr of Varget

 

[JEFFPPC]

I have used both jamb the bullet and false shoulder until this year. I tried something a friend figured out. It works. Load a 6br case up to a fraction below the shoulder case junction with Clays powder. He used a plug of modeling clay, I used a plug of toilet paper jammed into the neck. No bullet, do not oil the case have it dry and oil free. Shoot it. Then cut your neck to the desired thickness and your done.Very straight necks result.

 

[Lefty Trigger]

Well I made up 50 rounds with the bullets seated about .030 long and went to try making brass, epic failure! Not one round fired off so clearly this is not going to work. When I got home I measured the rounds and it appears that closing the bolt simply pushed the bullet back in the case and the firing pin pushed it a tad more. Every one had a slight dimple in the primer. Looks like I'm going to have to try the false shoulder method??

 

[Danley]

Sounds like you had very minimal to zero neck tension. Are you using a bushing, or non bushing sizing die? With adequate neck tension, a hard jam is all you need. I fireform with .003” neck tension & .020 jam.

 

[comagutsa]

Well I made up 50 rounds with the bullets seated about .030 long and went to try making brass, epic failure! Not one round fired off so clearly this is not going to work. When I got home I measured the rounds and it appears that closing the bolt simply pushed the bullet back in the case and the firing pin pushed it a tad more. Every one had a slight dimple in the primer. Looks like I'm going to have to try the false shoulder method??

Yep I use about 006 neck tension when using jam method.. But I hydro form now.. Still yet to try the false shoulder

 

[Lefty Trigger]

Before I go through all the steps of the "false shoulder" thing I decided to try something else. I Removed the expander ball from my resize die for maximum neck tension and used a q-tip and alcohol to remove all traces of lube in the necks. This will give me .007 neck tension and seated to .025 jam I'm think that will work,... we will see.

 

[JEFFPPC]

Well I made up 50 rounds with the bullets seated about .030 long and went to try making brass, epic failure! Not one round fired off so clearly this is not going to work. When I got home I measured the rounds and it appears that closing the bolt simply pushed the bullet back in the case and the firing pin pushed it a tad more. Every one had a slight dimple in the primer. Looks like I'm going to have to try the false shoulder method??

If your pushing bullets back in the case with .003 jamb you need a tighter bushing. Also, when I use this method I probably have at least .030 jamb if not more. I have made several thousand cases with this method, it works fine.

 

[swd]

I use touch plus .090” with about .006” neck tension, soft Winchester primers for fire form only and if your action has a spring loaded ejector take it out.

 

[JFrank]

Before I go through all the steps of the "false shoulder" thing I decided to try something else. I Removed the expander ball from my resize die for maximum neck tension and used a q-tip and alcohol to remove all traces of lube in the necks. This will give me .007 neck tension and seated to .025 jam I'm think that will work,... we will see.

Good idea Eric,
If all else fails you can call DB brass services back east for hydra forming
Jim

 

[Lefty Trigger]

Ok increasing the neck tension along with removing the ejector did the trick I managed to get 45 formed cased, one split at the shoulder and 4 would not fire off. I'm going to try softer primers on the next 50 and go again.

 

[swd]

Also if you have a really strong extractor, snapping the round into the bolt face by hand can help too.

And don’t use any lube of any kind for bullet seating.

 

[Bob L.]

Before I go through all the steps of the "false shoulder" thing I decided to try something else. I Removed the expander ball from my resize die for maximum neck tension and used a q-tip and alcohol to remove all traces of lube in the necks. This will give me .007 neck tension and seated to .025 jam I'm think that will work,... we will see.

I only go through 2 steps for the false shoulder method. Expand the neck with a .264 mandrel and size with my normal 6 BRX die. Last time I fireformed, I had no failures to fire in 220+ cases. I use a dedicated fire form barrel and the least expensive ~105 gr bullets I can find. I think I used Hornady most recently and did not even have to adjust my seating die.

 

[jr600yd]

If you used the false shoulder method at the start you’d be done by now.

 

[Lefty Trigger]

Round two went perfectly, 56 cases and no issues. Used standard Federal small rifle primers this time as they are softer and maximum neck tension all worked like a dream. Actually I think the best would be to send brass to DJ's and just be done with it!