Fireforming 6BRA from seasoned 6BR Lapua Brass

[RAG]

Giving thought to moving from 6BR to 6BRA for varminting. I have about 750 pieces of Lapua with an average of 15 firings. Used to be 800, but recently I donated 50 to fireform to Dasher, and only 33 of them made the trip, lol.

Since 6BR-to-6BRA is a much shorter journey than 6BR-to-Dasher, I'm wondering if I could expect to keep at least 95% of my cases without the shoulders splitting. Thoughts/guesses?

 

[DJSBRS]

Provided you had a flame type annealer, you should anneal right on the shoulder case wall area to soften it up and to flex and expand to the new location. You should only lose around 2% following that process.

DJ
DJ's Brass Service

 

[mikeinct]

We have 3 types of Imp. 6mmbr between us. The 6MMBRA "ripper mary's] rifle it is not only one of the most accurate at our game [1KBR steel targets]. The little round worked well at matches doing the fireforming for it. I don't think you could have picked an easier/better 6mmbr to "Improve". Enjoy the ride. mike in ct

 

[urbanrifleman]

We have 3 types of Imp. 6mmbr between us. The 6MMBRA "ripper mary's] rifle it is not only one of the most accurate at our game [1KBR steel targets]. The little round worked well at matches doing the fireforming for it. I don't think you could have picked an easier/better 6mmbr to "Improve". Enjoy the ride. mike in ct

Agreed.

I took my old 6br cases with 15 firings on them and had the kids at July 4th shoot them and now they are 6bra. Some did not blown out all the way but I didn't lose a case.

 

[bugman]

I have done the exact thing you are proposing. The difference was the 6BR brass was only 5 to 7 times fired. I was not changing much because the BR and BRA reamers were both .104 FB and .268 necks. I increased the AMP code by 2 points, and lost 1 case out of 300 to fire forming. The BRA headspace is indexed off the neck-shoulder junction....so, very little was need to prep these cases.

 

[Mark W]

Agreed.

I took my old 6br cases with 15 firings on them and had the kids at July 4th shoot them and now they are 6bra. Some did not blown out all the way but I didn't lose a case.

I’ve been there and done that! I bought 200 pieces of retired BR brass from a member here and fired them all on a prairie dog shoot. Every one of them fire formed perfectly without losing a single piece.