Ackley Improved Education

[Lonewolf74]

One thing to keep in mind is depending on the brass manufacturer and how their headspace tolerance is you may or may not be able to fire a conventionally loaded or factory loaded round.

I had this issue with my last wildcat based on a 338 Norma case. I designed the reamer with the standard -.004 for headspace so there would be a slight crush fit for forming. Once I received my Peterson brass I found it was .011 short of CIP spec headspace so I would not have a crush fit regardless. I sized up the neck to create a false shoulder so I could form my brass. You could perhaps get away with just jamming the bullet, I don't entirely trust that however.

 

[woodsman1991]

I ran into this exact issue of head space tolerance with some 30-06 brass that I was using in a 338-06 AI. Some brass was simply too short and would not permit full primer strike for ignition.

 

[Varmint Hunter]

If 40* shoulders and reduced case taper are your goals, along with a lot of performance from a given case, look at Sherman's website.
Some cartridges are able to be fire formed from a factory chambering or variant of the same case.
The others he has available, of ADG manufacture.
Headstamped Brass
Dies
Reamers/Gauges
Data
In some cartridges there are multiple reamers, for the length FB you need.
It doesn't get much easier overall. Of course there are different ways to accomplish some of the needs.
I'm about to build a SS and a Mega, for my 4th and 5th Sherman chamberings.

Phil,

I think you're addicted.

 

[Phil Rizzo]

Well I have a couple oddballs, but for the most part Mr Rich's designs fill my needs, and do it well!

 

[RichCoyle]

30/30 brass is weak as a kitten, does not take much pressure, been there, done that!

Same with 348 Winchester like you said. Been there done that. Clean it up with a 378 weatherby shortened it to get the job done.

 

[Mark37082]

Does fire forming brass to AI mandate trimming after first firing? I have only purchased AI brass. Trimming is not my favorite pastime.

 

[Phil Rizzo]

Does fire forming brass to AI mandate trimming after first firing? I have only purchased AI brass. Trimming is not my favorite pastime.

Not in my experience with 25/06AI and 25/06 brass.
With a 25 Sherman LA I used 280AI brass, necked down and then blown out. Mr Rich's reamer must be designed just right for it, also. No trim.

 

[lancetkenyon]

Does fire forming brass to AI mandate trimming after first firing? I have only purchased AI brass. Trimming is not my favorite pastime.

Most of the time, when blowing out the parent case to an Imp 40° case, fire forming will shorten OAL by a significant amount. Enough that trimming does not need to be done for up to 7-8 firings.

 

[FEENIX]

Most of the time, when blowing out the parent case to an Imp 40° case, fire forming will shorten OAL by a significant amount. Enough that trimming does not need to be done for up to 7-8 firings.

This!

 

[Mark37082]

Most of the time, when blowing out the parent case to an Imp 40° case, fire forming will shorten OAL by a significant amount. Enough that trimming does not need to be done for up to 7-8 firings.

Not in my experience with 25/06AI and 25/06 brass.
With a 25 Sherman LA I used 280AI brass, necked down and then blown out. Mr Rich's reamer must be designed just right for it, also. No trim.

After thinking about it more this seems logical.

 

[FEENIX]

After thinking about it more this seems logical.

My .338 Thor has a 45° shoulder angle.

The brass OAL is .046" shorter.

 

[MtPockets]

My .338 Thor has a 45° shoulder angle.
View attachment 559677
The brass OAL is .046" shorter.

That's interesting.
I thought the hydraulic forming would've got it much closer to final dimensions than that.

What did you end up with for a powder charge and velocity?

 

[FEENIX]

That's interesting.
I thought the hydraulic forming would've got it much closer to final dimensions than that.

What did you end up with for a powder charge and velocity?

Without any powder/primer, it's not too shabby.

I am still fire-forming off the chamber while playing with other bullets/powder.

 

[Phil Rizzo]

Mark, as reference you can normally run a max or close to max load from the parent cartridge data, in an improved chamber, when fire forming.

I never do more than I have to when forming to warm the pockets up before real pressure on round 2 or possibly 3.
Sharp crisp angles at the top and bottom of the shoulder are the goal, but there is no sin in the process taking 2 firings to get there.

Blow out loads can blow your mind concerning precision, trust me.