Fire forming

[bigdumboy]

Good afternoon
I am new to fire forming cases the gun is 25-06 ai. My question is should I have the bullet just into the lands just a little to make sure it pushes the shoulder out to form the new case ? Some of the cases have a little rounded shoulder. My think is if the bolt closes just a little tight that should push the case back against the bolt face. Is the thinking right ? The load is not hot at all any information or advice would be greatly appreciate.

 

[Mikecr]

Ackley chambers are designed a bit short in head spacing for a slight interference, just for fire forming.
On firing the body-shoulder junction moves forward to increase shoulder angle. When it does this, it pulls the neck-shoulder junction back a bit, for near perfect form.
You shouldn't need to jam bullets for this.

 

[bigdumboy]

Ackley chambers are designed a bit short in head spacing for a slight interference, just for fire forming.
On firing the body-shoulder junction moves forward to increase shoulder angle. When it does this, it pulls the neck-shoulder junction back a bit, for near perfect form.
You shouldn't need to jam bullets for this.

Any thoughts on why the shoulder is more rounded than sharp. Do you think maybe I should increase the powder charge just a little bit to see if it pushes them out a little sharper the only reason I'm asking I have never done this before and I just wanna make sure I get these right

 

[bluedog69]

Only experience I have is a buddy of mine had a 257 roberts AI. He bought factoy ammo and shot them to fire form them then he reloaded them.

 

[Cemetery21]

My experience is that the shoulders don't shape up perfectly until the second firing. My only AIs have been 223, so idk if that applies to all Ackleys.

 

[sturner]

I did a 22-250 and a 260 didn't jam lands just loaded a light load and shot em

 

[gemihur]

Fire-forming requires sufficient pressure to shape brass for increased case capacity.
You gotta punch those shoulders sharply.
The ones I have the most experience with are 7-30 Waters but they move the shoulder quite a bit at fireforming.
The ones you've got rounded can be reloaded and fired with full-house load data and they'll be as sharp as your chamber.
You can look at the C.O.W. method (Cream of Wheat) on YouTube.
old school guys do it that way, I waste bullets.
In waste I mean they shoot durn near MOA even at the fire-forming stage.

 

[MagnumManiac]

The rounded shoulder is normal, it takes another full power load to fully form a sharp shoulder.
In my 22-250AI, it can take 3 shots with neck sizing only before the case fully fills the chamber.
My 375 Bee takes 5 firings/sizings before the neck grows back to 2.850". They lose .030" in neck length when fireformed from H&H brass.

Cheers.

 

[L.Sherm]

I suggest you read up on why the majority of people including me jam into the lands or do the false shoulder method to AI.
Theres hydraulic forming dies cream of wheat method etc. also

 

[Rick Richard]

Don't jam and fire at Least two firings to get it fully formed.

 

[Seabeeken]

Good afternoon
I am new to fire forming cases the gun is 25-06 ai. My question is should I have the bullet just into the lands just a little to make sure it pushes the shoulder out to form the new case ? Some of the cases have a little rounded shoulder. My think is if the bolt closes just a little tight that should push the case back against the bolt face. Is the thinking right ? The load is not hot at all any information or advice would be greatly appreciate.

The rounded shoulders are a lack of pressure to fully form them. Ackley said to use a snappy load to form. A fast powder is a good way to do this.
Take a sharpie and color in the neck shoulder junction of a case with bullet in place and chamber it. If the sharpie is worn at the junction when removed, it is headspaced fine for forming. Some are not very tight and need to have the bullet jammed a bit to hold the case head against the bolt face to keep the brass from flowing from the rear of the case during fire forming.
the case should get shorter after forming because as the body moves out and shoulder moves forward, it pulls brass from the front of the case. If it doesn't get shorter, then The brass flowed from the back which could lead to a head separation. I've seen this before. The case should be a snug fit when closing the bolt as others have said. Ackley would set barrels back .004" to create this condition. Enjoy the 25-06 ai, it's a good one.

 

[Petersen]

I have a 25-06 ackley. I did the pistol powder, cream of wheat, and tissue to get them mostly formed. Then I loaded them to start on
Load development and they were fully formed after the first firing with bullets. Without cream of wheat I used light bullets jammed with faster burning powders and they formed decent.

 

[Tiny Tim]

If chamber is set correctly and you use quality brass (uniform), there should be no need to jam the bullet. A mid to max load for the parent cartridge should form very well. Like others have stated, use a faster powder for caliber and it will likely take a couple firings to fully form that sharp shoulder. It also helps to anneal after the first fire forming.

 

[Gibbshooter43]

I have a 243AI, a 250 Savage AI; a 25;06AI; and a 260AI All fire form just fine with my normal shooting load. No jamming needed, and accuracy is not much off the final product. I wouldn't hesitate to use a factory load in my AI chamber while hunting and fire form in the process.