What do I need for making 6mmBR brass into 7mmBR brass

[Lefty Trigger]

I know I can just buy it but I have about 700 pieces of Lapua 6mm BR brass and would like to make about 150 of those into 7mm BR brass. Do I just run them through my 7mm die or get an expanding mandrel?

 

[jds holler]

I'd lube well, and run one through your 7 die. Should be no prob. If it is a problem, use one intermediate expansion step with an in between diameter. jd

 

[Big Mc]

I know I can just buy it but I have about 700 pieces of Lapua 6mm BR brass and would like to make about 150 of those into 7mm BR brass. Do I just run them through my 7mm die or get an expanding mandrel?

Send it to DJ . Just my two cents Tommy Mc

 

[sandwarrior]

Run a tapered expander down the neck and VOILA!! you have 7mm BR

 

[Bruce W]

i used the K&N expandiron tool .( Lapua brass) Then a light neck turn. See if they fit your chamber. If the shoulder is too far front just lower your full length size die slowly to get that perfect chamber fit.
The fire form method will make the necks a little longer which may be desirable . In my gun the necks were a little short which gave me a nasty carbon ring where the case was shorter than the chamber.I used a bounty towel cut 3 ich x 1/2 inch, roller it up and stuffed into the case after 22 gr. of bullseye

Case with towel in neck is the bullseye formed case. visibly longer

 

[Longtrain]

I used a bounty towel cut 3 ich x 1/2 inch, roller it up and stuffed into the case after 22 gr. of bullseye

Really, 22 grains of Bullseye? I FF Dasher and 223AI cases using 8 grains, the report is as load as a pistol shot and flame shoots from their 30” barrels, can’t imagine what 22 grains would be like.

 

[ckaberna]

You could always load with cheap 6mm bullets and fire into a safe backstop. When you eject the case will be a fireformed 7BR.
Don’t shoot this way over about 75- 100 feet.
I use an old shot out barrel that is chambered the same.

 

[Old Navy]

Run a tapered expander down the neck and VOILA!! you have 7mm BR

Perfect!

 

[Lefty Trigger]

OH, forgot to ask. If its a REMINGTON 7mm BR Factory Chamber as in a old rifle or XP100. It may not work. Base of Factory Remington 7BR brass is about .005 smaller than Lapua brass. .465 Rem vs .470 Lap.

No its a modern chamber, new Shilen barrel.
I tried lubing up a few Lapua cases and run them in my die and the results were less than stellar so I just ordered another hundred Peterson 7mmBR brass.