Fire forming Lapua 6BR brass to 6mm BRX

[LONGRIFLES]

Hi,
Can anyone give me some solid information on the best way to fireform the 6mmBRX case. I have a customer gun that I have rechambered and want to try some fireforming techniques to help him get started correctly with his new gun. He has tried in the past to make brass and has had problems with case head separation. His old chamber measured about .005 longer than the go guage which indicates headspace problems. I plan on trying to form some 6BR Lapua in the new chamber. Any help would be appreciated greatly since I don't have any experience with this cartridge.
Thanks
Ronnie Long

 

[Josh11]

Easy way to do it, is to just load a Hornady amax or any other cheap bullet with 28-29 grains of varget or rl15 and shoot it. Mine shoots bug holes with it. Make sure you jam your bullet a fair amount.

 

[nosualc]

There's a really good article here:

http://www.6mmbr.com/6improvedform.html

I use the neck turning technique (#3 in the article) with a .010 jam and 30 grains of Varget, but I have a tight neck chamber. Even fire-forming it shot fantastically. I lost 4 of 110 cases during fire-forming (split shoulders).

Good luck.

-nosualc

 

[shooter63]

i use 30.5 gr. varget 450cci mag primer 107 smk 25th. into rifling with at least3th. nk tension you need tension on bullet this is a brx. have had 4or5 inthe past all no turn nks . so if your nks. need turning do that first if not loader up mine shoots some impressive fireformed groups good luck shooter63

 

[Scott Harris]

I run a 6.5mm mandrel through new 6BR brass and then run it through a properly headspaced 6BRX die. 28.5gr of H4895 and a 105 grain bullet of your choice. Accuracy is fantastic: shoot it at a match. I usually get 1-2 shoulder splits per 100 though.

 

[DennisH]

I run a 6.5mm mandrel through new 6BR brass

Why the 6.5mm mandrel?

 

[Scott Harris]

No particular reason, next major size up to create a false shoulder. I suppose you could fine tune the mandrel choice,but the 6.5 worked perfectly.

 

[Raptor]

I too was new to the BRX this year and had the same questions. I bought new Lapua blue box brass and so far I have formed over 150rds and only lost one case.

Robert Whitney gave me good advice along with others on here. I loaded 30grs of varget with 105 amaxs and seated them at least .025 long in a new case.

The only problem I had was I was using fed. primers and having some problems with piercing them. Once I went to Wolf SRM or the CCI 450s that problem went away. Perfect cases!!

 

[Killshot]

Dasher/BRX: 30.5gr of Varget with a 105-108 bullet and a .030" jam in virgin brass made 200 perfect cases for me. Good shoulders and blow-lengths.
And very, very accurate as well.

 

[nfa1eab]

BRX: 30.5gr of Varget with a 105 AMAX bullet (moly'd) and a .020" jam, Wolf SRM primers. I run a .257" mandrel in the brass and then create a false shoulder for a crush fit in chamber with a Redding full length type S bushing die (.267" bushing for old Lapua brass and a .272" no-turn neck). Have formed over 300 cases without a single failure. Good shoulders and blow-lengths. And accurate at 600 yards. Have to remember to turn the knob more though as they are around 2,750 fps in a 31" Barrel.

Might want to consider bushing the bolt for the .062" firing pin (Gretan). I had primer piercing issues at lower pressures until this was done. Now....no issues. 15 firings on brass before I started splitting a few necks. Brass was annealed after 9 firings, probably needs it again.

Ed

 

[Phil]

I have never used the jamb method,BUT i remember reading somewhere that it is a good idea to remove the ejector to keep it from pushing forward on the cases while forming initially.........

Might want to look into that one..

 

[lpreddick]

different strokes for different folks...i ff cases using the cow process. i size a false shoulder into the neck after expanding with a .25 cal expander. use a small pistol magnum primer and clays powder (the charge depending on which case i'm fireforming). fill case into the neck with cow and plug with a dab of lanolin. very slightly lube the forward portion of the case ( the part blown forward in the brx and ackleys) and BANG. i used to BANG at the range but now do so in my shop using a large bale of fireresistent attic insulation...poke a hole in one end and insert barrel about a foot or so into the bale and whuuummmppp is all you hear. even the ackley cases form 95+% and there is no wear in my barrels.