6BR Improved Fire Forming

[Mark W]

I’m looking for suggestions on a starting point to fire form loads for my new zero freebore 1:12 twist 6BR improved. I won’t be shooting anything heavier than 70 grain bullets and all of the data I can find is for 105 class bullets.

Edited to add that I’m saving the COW for breakfast and hoping to find a FF load worth of taking on an upcoming prairie shoot.

 

[JEFFPPC]

Why not use a COW type method for the initial firing and save rounds on the barrel ?

 

[Ozzyblu]

I am fire forming on a PD shoot as well.

30 grains of Varget and 87vmax.

 

[22DASHER]

I would work up a load for whatever "Extra" supplies you have laying around....Whatever it is will probably shoot. If I was going to make a special purchase for fire forming I would stick with H322 and 55 grn Nosler ballistic tips. That'll light things up.

 

[Webster]

I’m looking for suggestions on a starting point to fire form loads for my new zero freebore 1:12 twist 6BR improved. I won’t be shooting anything heavier than 70 grain bullets and all of the data I can find is for 105 class bullets.

Edited to add that I’m saving the COW for breakfast and hoping to find a FF load worth of taking on an upcoming prairie shoot.

Which 6R improved cartridge. My rifle shoots under 0.500" FF 6BR to 6BRX. 14 twist.

 

[Mark W]

Which 6R improved cartridge. My rifle shoots under 0.500" FF 6BR to 6BRX. 14 twist.

It’s a just BR with a 40 degree shoulder or what is also known as BRA. The reamer print called it BR Imroved.

What powder and bullet are you using to FF for your 1:14 BRX?

 

[tmwinds]

Mark, when forming my 6BRA brass I used the data for a regular 6BR. In my case I was loading 80 grain bullets in a 12 twist and I used 29.5 grains of IMR-8208 with the 80 grain bullet. This is a light to moderate load and formed my brass perfectly and was very accurate. Try googling Hodgdon Reloading Data, You will find data for about every powder bullet combination.

 

[timeout]

30 gr of varget under a 107 smk. Brass was run through a hydro form dye first though..... shoots as good as the formed case.

Did you not read the OP's request? He requested load info for a zero freebore 1 in 12 twist.

 

[Webster]

It’s a just BR with a 40 degree shoulder or what is also known as BRA. The reamer print called it BR Imroved.

What powder and bullet are you using to FF for your 1:14 BRX?

Any normal load that isn't excessive. 33.3 gr of 8208 is what I use.

 

[Jeff A]

You should keep the fire forming load on the light side because the regular 6BR case will not make full contact with the chamber walls during case expansion. As a result, you can get excessive thrust on the bolt face as the case head tends to move rearward. It will look like excessive pressure.

 

[Webster]

You should keep the fire forming load on the light side because the regular 6BR case will not make full contact with the chamber walls during case expansion. As a result, you can get excessive thrust on the bolt face as the case head tends to move rearward. It will look like excessive pressure.

Jam the bullet.

 

[Mark W]

Thanks to all that responded!!!

I made it out this afternoon to do some fire forming and barrel break in. I put one round through it at 50 yards to get on paper. After cleaning the barrel and adjusting the scope, I moved my target to 100 yards. Shots 2 and 3 went into 1/2”. I cleaned the barrel again and zeroed the scope. Shots 4,5, and 6 then found their way into a .363 cluster before I called it quits for the day.

The cases formed good but I was getting a little soot on the necks. I’m going to try hitting them a little harder and see how it does.

 

[Webster]

Thanks to all that responded!!!

I made it out this afternoon to do some fire forming and barrel break in. I put one round through it at 50 yards to get on paper. After cleaning the barrel and adjusting the scope, I moved my target to 100 yards. Shots 2 and 3 went into 1/2”. I cleaned the barrel again and zeroed the scope. Shots 4,5, and 6 then found their way into a .363 cluster before I called it quits for the day.

The cases formed good but I was getting a little soot on the necks. I’m going to try hitting them a little harder and see how it does.

I consider some soot on the necks as normal.

 

[Mark W]

I consider some soot on the necks as normal.

Fair enough! I’ll rephrase and say that it had a little more than I consider normal. I came home and loaded 5 more with 1/2 grain more powder. I’ll shoot those over the chronograph tomorrow and see how it goes.

 

[dedogs]

loaded 5 more with 1/2 grain more powder.

You came and asked for advice (which you got) but you don't say what powder/charge you decided to try. Please share. dedogs

 

[Mark W]

You came and asked for advice (which you got) but you don't say what powder/charge you decided to try. Please share. dedogs

I started with 28 grains of H322 behind a 70 grain Sierra Blit King which was jammed .010.

I also have some 70 TNT and 70 NBTs to try.

 

[dedogs]

I started with 28 grains of H322 behind a 70 grain Sierra Blit King

I'm with you, I'd hit them harder. That seems a pretty mild FORMING load. dedogs

 

[sdean]

Send them to DJ.

 

[farmerjohn]

I may catch hell for doing this, but the big boys told me when we first started shooting bra's how to fireform. Whatever load you have working for the match load, just run a .020 jam and shoot them in matches. My load behind Bart's 103s is 31.2 grs of 8208 which gives me 2945 fps and the fire form loads do the same with no more pressure thnt the regular loads. Got onefireform barrel I've never used for a bat and one for the panda that I used to form loads shooting prairie dogs one time. Two of my shooting friends do the same. That's why Ackley designed them to be improved.
Farmer

 

[TAJ45]

[QUOTE="farmerjohn, post: I used to form loads shooting prairie dogs one time. Two of my shooting friends do the same. That's why Ackley designed them to be improved.
Farmer[/QUOTE]

I like that, heh heh.