To BRA or not to BRA

[rijndael]

When you're fireforming the brass, do you have to jam the bullets to keep the brass against the bolt face, or does the base of shoulder provide sufficient restraint so you can jump them?

 

[Downhill]

To Bra or not to Bra, that is the question:
Whether tis is nobler the higher velocity'
To send the Barts and Bergers at greater speed.
Or to take the one hole ability of the 6BR.
That is the question.
(Still a fan of Shakespear!)

 

[dgeesaman]

When you're fireforming the brass, do you have to jam the bullets to keep the brass against the bolt face, or does the base of shoulder provide sufficient restraint so you can jump them?

With BRA the inner edge of the shoulder jams slightly in the chamber so your seating depth can be whatever.

Dasher forming is a whole other thing but it comes down to either creating a false shoulder to have the same effect as forming BRA or jamming the bullet and letting that restrain the brass.

 

[Texas Solo]

I’m not sure how it saves components though. A BRA shoots just as well fire forming as it does with formed brass in my experience. I won a club match while fire forming for my last BRA.

I've never fire formed brass, so I don't really know. But my understanding is that you use a lighter load jammed, verses your optimal target load. Maybe no accuracy diff at 100yds or 300yds, but at 600yds to 1000yds I'm sure there is.

 

[Mark W]

I've never fire formed brass, so I don't really know. But my understanding is that you use a lighter load jammed, verses your optimal target load. Maybe no accuracy diff at 100yds or 300yds, but at 600yds to 1000yds I'm sure there is.

No jamming required for a BRA if the chamber is set up correctly. I do run my fire form loads a little a little lighter, but I’ve had good accuracy out to 600 yards. I don’t have access to a 1000 yard range, so I don’t know how well they would perform at that distance, but I would assume it would at least need more elevation and windage dialed in due to the slightly lower velocity.

 

[Forum Boss]

I recommend putting the bullets into the lands when creating the 6BRA. In my experience that increases consistency. With all of my 6mm barrels I have also got best accuracy with bullet contact into lands about .007-.009 past "first touch". YMMV.

That "first touch" is with a gently applied Hornady tool, measuring four times. I will see a very tiny mark on the bullet and the bullet will usually fall out when I tilt the barrel muzzle up. I mention this because my "first touch" may technically be a couple thousandths in. Also, some guys using the Hornady tool aggressively might be much farther in, because they push the rod in hard. I have found that a gentle push and a couple very light taps gives me a consistent read 3 out of four times, within 1-2 thousandths.

Back to the BRA, I would fire-form with some bullet contact. But as others have noted -- you can get good accuracy, so form the cases in a local match -- don't waste those bullets!

 

[Jeff Porter]

I fire formed some new Lapua brass today for 6BRA while practicing some sling prone work using 107 SMK 0.015” off touch, 30.1 Varget and 450 primers. Nice sharp shoulders formed.

Can’t complain about the accuracy or the SD /ES during fire forming. Shoot it in a match while fireforming. Shot two came down two clicks and had a good X count clean string. Ended up 499/500 for the day with the 9 going right where I pointed it.