My neww Cooper Varmint is chambered in this, my first experience with anything other than factory cartridges.
I have been told I can fireform factory loads but they are too hot to do a good job of forming and brass life will suffer. A mild but not underloaded load with a light bullet is what someone has suggested.
Also I have heard that it is best to neck size only for this round for better accuracy and brass life, which makes sense, but should the fireformed brass be full length resized the first time it is loaded?

cummins

"Someone" told you wrong. Fire-forming loads should be full power factory or high end handloads. Cases will come out fully formed and ready to go.

I would not full length resize any case unless it was necessary.

Ray

C4x4; First off let me say that I don't own the AI version of the 25/06, but do the 7x57 and 30/06 AI and have never lost a case from fireforming, I use the starting load and long enough bullet to contact the lands for fireforming, the cases eject perfectly formed and I FL resize both.I cannot make any claims as to useing factory ammo for fireforming,because I haven't done it, but I think it should be fine as that was the way it was designed by Ackley, I just like to put the ogive on the lands for alignment making a concentric formed case. For the 7mm I have RCBS dies and for the 30/06 I have Redding, I ended up sending the 7x57 dies back with a couple fired cases and RCBS polished some of the taper out of the dies, at no charge of course, my chamber had less taper than what their dies were speced to, but they work perfectly now, you can't beat customer service from either one of those companies. After fireforming I FL resize and trim to a uniform length, then anneal the necks, and load. You will find cases stretch very little and last a long time, I still have some of the original cases formed for the 7x57 and they are fine, although I really don't push velocity to the limit, 140 grainers at 3050. I think you will find brass is easy to form and will last a long time, enjoy.

I have a 257 Roberts Ackley Improved that I chambered with a 257 Roberts case as a go gauge. This was the classic mistake, as the sharp ring at the base of the neck of the Ackley chamber will cut into the brass .004" when the firing pin pushes it forward. Then the case grabs the case wall, the rear of the cartridge is pushed back, and the case gets .004" of case stretch just behind the shoulder where a crack will show.

I have tried ~100 experiments in fireforming in one step with long brass life. I can't do it. But I sure can in two steps:
1) step one, lubricate the case with high pressure lubricant, like moly creame or grease, 10 gr pistol powder in case, fill the rest of the case with Cream of Wheat cereal, no bullet, and either shoot straight up, or cap the case mouth with Ivory soap to contain the cereal, and shoot horizontally.
2) The case shoulder is now half formed. Load a standard Ackley load and get sub moa accuracy. Now the case shoulder is fully formed with long brass life.

Half-forming a case loaded with pistol powder and cereal is far from the best way to go.

I have formed wildcat brass for 30 years, and the best method -- the one least stressful to the brass and most conducive to the best case life -- is using a powder that's bulky enough to fill the case (compressed load) and yet fast enough to form it on the very first firing. And, the bullet needs to be seated out as long as possible, preferably engaging the rifling.

This set-up gives the utmost support to the case during the forming process and gives you the best case life possible (assuming proper loading techniques ensue). It also forms the brass fully in ONE firing.

Also make sure your cases are free of any lube and that your chamber is dry. You can swab it with acetone or a similar product to remove any traces of oil.

As a testament to this method, I have some 7mm Bullberry cases that have now seen well over 2 dozen full-power firings. I have sectioned a couple of them, and there are no weak spots, and the primer pockets are still tight.

And this is a wildcat made from "thin" 30-30 brass...

The 7mm Bullberry cases I referenced have always been partially full-length sized, by the way.

cummins

For some reason, fire-forming cases from a factory shape to an "Ackley" shape has grown to be a major undertaking requiring all kinds of special warnings and caveats. Nothing could be further from the truth. It is one of the easiest things you can do. The fire-forming guru, P.O. Ackley hisself, barely touches on it in his books. He generally says it all in one or two sentences - take a factory cartridge, load it and fire it. Voila, a fire-formed case is the result. From then on, load and shoot like you would any other case. It's not rocket science.

JMHO

Ray

Bobby,
Are you contradicting me?


Cheechako,
I quickly and easily designed, for Rocket Research Co., a new controller to improve [over previous designs] the economy and steering control loop phase-gain response performance of the then proposed Midget Man ICBM in partnership with then Martin Marietta.

That was rocket science.
That was easy.
I only charged a few consulting hours.
Getting Ackley cases to form in my chamber that is head spaced per the parent cartridge is hard.
I have allot of hours into that question.

25-06 IMP circa 1966. Fire formed full loads sized from 30-06 untill commercial ammo was available around 1970 I believe. We than use to just fire the commercial ammo in the field and to get formed cases. Guess I wasn't smart enough to know I was having some kind of problem.

In all honesty ,however, when commercial ammo was used the bolt handle was hard to close crushing ,I'm sure, the brass at the shoulder neck junction. This may have been an unrecognized benefit at the time. So some time in the 70s or 80s I took a standard 25-06 reamer and spun it by hand untill it reduced the hard bolt handle closing. From what I'm now reading that may have been a step in the wrong direction ,but I never noticed it. It really is a beneit to be born fat, dumm and happy.roger

quote:

And, the bullet needs to be seated out as long as possible, preferably engaging the rifling.

This set-up gives the utmost support to the case during the forming process and gives you the best case life possible (assuming proper loading techniques ensue). It also forms the brass fully in ONE firing.

yup- reloading 101

There is another method (as if you need more), the Ackley chambers/reamers may vary depending on the manufacture (Clymer, Pacific Gauge, etc). A sure fire (pardon the pun) way to get the headspacing correct is to neck the .25-06 brass up to .270 and then in stages, neck it back down to .25 until the bolt will close with heavy feel. Your headspace cannot be wrong then and you will not lose any cases. A hot (not exceeding listed) standard .25-06 load with a light bullet will fireform tham perfectly. You need to make sure that in full length sizing, you do not set the shoulder back. All it takes, a swheeler said, is a little care and Reloading 101.

quote:

neck the .25-06 brass up to .270 and then in stages, neck it back down to .25 until the bolt will close

Excellent advice. Or you can use .270 or .30-06 cases to begin with and resize them similarly only enough to enter the chamber with slight resistance from the bolt handle as you turn it home.

tnekkcc: Your chamber is clearly a tad on the long side. AI chambers should be cut to allow a factory cartridge to enter and use the same datum point at the juncture of the neck and shoulder as the factory load. A mistake that is often made by gunsmiths is to rechamber to AI without setting back the barrel slightly first. This nearly always results in an overly long chamber and a problem similar to that you are experiencing.

4x4,

I've been doing the cereal & pistol powder thing for my 25-06 AI. Works good.

That said, I will be ordering a Hydroforming Die from the Hornady Custom Shop soon.

quote:

Originally posted by tnekkcc:
I have a 257 Roberts Ackley Improved that I chambered with a 257 Roberts case as a go gauge. This was the classic mistake, as the sharp ring at the base of the neck of the Ackley chamber will cut into the brass .004" when the firing pin pushes it forward.

If the chamber was headspaced properly, then the case CANNOT be pushed forward by the firing pin. I've chambered a few AI cases and have used the parent case as a go gage, never been a single issue.

I am now in the process of fireforming for my fifth AI I hace never found it necessary to seat bullets into the lands. If properly chambered with an Ackley go gage one will have a crush fit on virgin brass. I have a 243 AI
7x57 AI A223 Rem AI, and am on my third 257 Rob AI. If properly chambered factory ammo will work OK if not you have a wildcat.

Lyle

Looks like some statements or assumptions need clarification
1- I don't think the fireing pin blow will setback the shoulder on a case that is a crush fit in the chamber, but the explosive force of the primer against the bottom of the primer pocket can and will set the shoulder back a small amount, and as the pressure created by the ignited powder charge rises it stretches the case back until it is stopped by the breech bolt, it happens everytime you fire a rifle, you just don't see it because the case is stretched back out before you eject it. Most ALL reloading manuals show an example of a protruding primer, caused by a LIGHT load, there wasn't enough pressure to stretch the case back out. This is not an assumption, ask any cast bullet shooter who shoots extremely light loads, after several fireings the shoulder will be pushed back enough to start getting misfires, we're talking rimless cartridges here. Now if you have a chamber that is excessive or max on headspce the fireing pin blow will move the cartridge forward until contact with the shoulder stops it, then pressure from the expanding gas will stretch the case until stopped again by the bolt. Seating the bullet to contact the lands will alleviate some of this forward movement in both cases, but most importantly, for me anyway, is that the case will be held centered in the chamber until fired, and YES a crush fit or false shoulder will also center the cartridge in the chamber, but I want brass formed as concentric as possible, the improved chamber leaves a lot of clearance around the shoulder.

2- According to PO himself, when chambering to an Ack Imp- the GO gauge becomes the no-go for the new chamber, so if it is chambered correctly at best you will have a zero clearance fit with your factory ammo, but all the factory ammo is made to chamber freely in ANY gun head spaced on a saami spec go gauge. So when you fireform in an improved chamber, the loaded round is LAYING in the bottom of the chamber, the brass expands to the clearance side leaving brass with necks and bodies thinner on the one side.
3- So you can fireform with factory loaded ammo just fine, that's the way it was designed to be done, if you lost your ammo you could just buy a box of factory fodder and still hunt, save the empyies and reload them, but you are not going to get the most precise, best quality formed brass possible, after all this is why some people reload, to get the best possible. So really it is up to you, if you just want some brass to reload, fire any old ammo in it, if you want to squeeze all the potential accuracy out without going into benchrest techniques like neck turning, put the ogive on or into the lands, it will shoot better than that lopsided stuff formed the other way. As usual just my .02. Scot

We bought a 257 Roberts Ackley Improved reamer in 2001, and my rifle got a Roberts headspace. I learned that was .004" too much headspace.

In the subsequent 3 rifles we did, we put a .005" thick piece of masking tape on the case head of a 257 Roberts Ackley improved case that I had fire formed in my rifle, full length sized it in 257RAI dies, took the tape off, and there was the Go gauge.

Those next 3 rifles fire form brass in one shot.

quote:

So when you fireform in an improved chamber, the loaded round is LAYING in the bottom of the chamber, the brass expands to the clearance side leaving brass with necks and bodies thinner on the one side.

I don't think so. The brass is centered in the chamber by the neck. It is irrelavent how much clearance there is between the body of the case and the improved chamber. The distance out-of-center is limited to the clearance of the case neck and the neck portion of the chamber, which is EXACTLY the same with a standard cartridge as with an improved cartridge. In other words, you get the same (very, very small) amount of off-center case expansion no matter what kind of chamber you are firing a new case in.

quote:

In other words, you get the same (very, very small) amount of off-center case expansion no matter what kind of chamber you are firing a new case in.

I don't think so! unless you call .006" very-very small> that is a country mile in reloading. If you have ever fired military ball ammo for accuracy, then you will know where the old saying"close enough for gov't work" came from. For some people this may be just fine, for others it's not good enough. Tolerance stacking is what we fight as a reloader, and the more we can remove the better the gun will shoot. Just like real estate-location-location-location, and for reloading concentricity-concentricity-concentricity I always figure when somebody asks a question give them as much pertanant information as possible, then let them decide what is good enough for them, in 1964 I didn't worry about any of this, I just wanted to shoot, but as the years rolled by I learned, from reading and mostly doing.