all right guys, discussion on one of the other boards is bringing this up. they are talkinga bout fireforming cases without the bullet, just using a filler. One person mentioned that it can create headspace to fire the standard cartridges in the rifle for expanding.

Is that accurate? I have a couple of Ackley Improved chambering and I normally just use a standard load and lighter bullet to fireform my brass and use all the shots to improve my ability. Is that bad?

One more questions, if you shoot loads that are on the hot side, slight bolt tightness after firing, will that create headspace? and if a rifle develops headspace, does that mean the action is shot or just that the barrel has to be cut and turned back?

thankseverybody.

Red

Red,

There are folks who use a small charge of fast burning powder, a filler and a plug of wax or some other substance to fireform their cases. It can require a pretty stiff hit to fully form a case. During the forming phase, the pressure drops as the case expands. When I fireform brass, I use a safe but stiff load to do the forming. Not one that would even come close to sticking a bolt.

A sticky bolt is a sign of excess pressure. Back it off. Continued battering of the lugs with excess pressure will most likely increase headspace as the structure and molecules collapse.

If the weapon developes excess headspace is the action safe to reuse? That would depend on the cause. If it's caused by abusive and excess pressure, I wouldn't touch it. But that's just me.

Good luck,

Malm

thanks. I don't get excess pressure on the fireforming loads, I was talking about a seperate rifle. I have one that I developed loads for, last winter, and they didn't have excess pressure, I have shot them now (between 90 and 100 degrees outside) and the bolt is sticking a bit. I was skeptical about using them anyways, since it is just 06 brass I am probably just going to chuck them. (I don't feel like pulling 50 bullets and don't like the idea of reusing gunpowder).

thanks again.

Red

With rimmed rounds, fireforming without bullets is duck soup, as headspace is not an issue. I would be very circumspect about forming rimless cases this way, however...

Dago,
quote
...............................................
"One person mentioned that it can create headspace to fire the standard cartridges in the rifle for expanding....
...I have a couple of Ackley Improved chambering and I normally just use a standard load and lighter bullet to fireform my brass and use all the shots to improve my ability."
................................................

I am going to assume that the topic we're talking about is fireforming cases for an Ackely Improved something and not a wildcat in the truest sense. Say like a Gibbs.

If the chamber that was improved was done correctly and it sounds like yours was then the headspace dimension is the same for the standrad chamber as well as he improved chamber. This was one of Ackely's design goals is that you could fire either cartridge.

However there are many guns out there that have been improved "too deep" and the headspace is NOT the same as the standard chambering. Fireing a standard cartridge in one of these rifles would be like fireing a round in a rifle with too much headspace. Those rifles would best be served by creating a tight headspace by some alternate means for fireforming. A couple of ways would be to create a false shoulder or seat a bullet long so that it jams into the lands.

I personaly use the Cream-of-wheat load with a paper wad in one rifle. But always in a case with a very tight false shoulder always ensuring a tight headspace. But theres little choice its a 6mm Gibbs.

Ray

I'll explain the case I refered to earlier on the other thread. I just got off the phone with the gunsmith who I learned it from. I'll write what he said:
What happens, is that when using unimproved cases in an improved chamber such as an Ackley, the neck shoulder junction is beat forward. It will first cause neck problems then headspace problems. Ackley knew it. He advocated the use of another action for forming. Ackley designed most of his chambers to work with factory ammo in a pinch, but not with a steady diet. This was all confirmed by a conversation the two of them had. The chamber becomes work hardened and can damage a reamer if it is bad enough. He also said he wouldn't buy a used rifle that had an Ackley chamber in it, unless he knew it was used right. Stainless barrels are more vulnerable than chrome-moly.
These were his words (summerized), and I respect his advice. It probably isn't a big concern, but it is something to think about. I am only suggesting that fireforming in a seperate gun is a better process.

If you have an existing .223 you want converted to .223AI a good 'smith will turn the barrel back a few threads to headspace it properly and when it is done right when you load a factory round you will be able to just "feel" the bolt close and when it's set up like this you won't have any problems with headspace or using factory ammo.

Spend a buck and talk to Darrell Holland about this as I think he cuts one of the best 223AI chambers around.

When the chamber has headspace (They all have some) the primer firing pushes the
case forward (not the firing pin). Pressure causes the case to stick forward. The primer may now protrude out of the case. If the pressure is "low" say 40 kpsi the primer will be
protruding upon ejection. If the pressure is "higher" he friction between the base and the chamber will be overcome and the case will stretch at the "stress ring".
When you fireform with low pressure the headspace may be increased by the case
shoulder hitting the chamber.
If you apply a light coat of oil to the case, not the neck, when you fireform many problems will be avoided. For one thing the "stretch" will not be confined to one location, and the case will
really "fit the chamber".
It would seem to me that it would take a lot of shooting to "work harden a chamber".
If the chamber had been cut with a dull reamer (particularly a single ) it would be delivered
workhardened.
Good Luck!

This is exactly the reason why Idiots should not design wildcats or improved cartridges, and people using them not understanding how they were developed and the process used to develop the case for them. To start with, if it is an improved cartridge to be fireformed, the only change should be "only" in the body taper, and/or shoulder angle, not Headspacing!!!!!!! The Headspacing should always be the same as the parent cartridge. If a change is made to Headspacing, then it should be considered a wildcat and be press formed, then fireformed from a longer case so Headspacing can be maintained. It's just that simple. To do it any other way is asking for trouble. If headspacing is not maintained within tolerance then stretching of the web of the case will occur, and thin out the web of the case will be the result. You can see the evidence of web thinning by a bright ring around the base or web of the case. There is just no way to get a consistence uniform resizing, as for as consistence case thickness when trying to Fireform a case in a chamber with excessive Headspace. Now with all this said, I know this is done most everyday, and with good results in some cases. But the potential for disaster is there. Personally I prefer to form wildcats or improved cartridges from brass with longer dimensions. Why??? Because Case thickness gets thicker as you measure toward the base of the brass, when blowing out the body taper and/or shoulder angle it will thin the brass. By starting with longer brass and press forming then Fireforming, case dimension thickness will be close to what a standard case should be for the pressure expected. Of course Neck thickness has to be observer, and if necking down, the neck of the case may have to be turned to reduce the thickness to spec.'s. If necking up, no turning may be necessary or it may, depending on how the case neck spec.'s out.

Thanks all. I think I am fine then, as it is just two rifles in with ackley improvements, and both chambers were done very well. And since they are both hunting and not plinking guns I won't be shooting them that often! :-)

It would be nice to have the skill and space to have a seperate setup for fireforming cases.

You guys are a great resource, thanks again.

Red

Actually the headspace of an improved cartridge is not the same as the parent round. The headspace of an improved cartridge should be .004 shorter than the parent case. This will give a crush fit when the parent round is loaded into an improved chamber and take up any variances at the shoulder/neck junction that may occur during manufacture.