Thread: Fireforming New Brass

Got a heap of new brass to fireform. Usually use any old "semi-suitable" powder and el-cheapo projectiles.
Anyone got any latest tips or tricks??

I normally use the "pre ai" factory cartridge load with a cup and core at paper, but you will find guys using small amounts of shotgun powder with wads of various material, cream of wheat etc.

I developed a load after running them through the FL die that shot brilliant.

What is it you're trying to achieve/form?

Depends on what you are fireforming to, and what are you starting with.

If it's an Ackley from the parent case then make sure you have a crush-fit when chambering at the neck shoulder junction. 0.004" was the recommended figure when fitting the barrel, but I would advise increasing this if possible via the starting case dimensions until the bolt is very stiff to close. DO NOT rely on bullets seated long to hold the the head back onto the bolt face. If in doubt form a false shoulder.
There is anecdotal evidence that imperial sizing wax on the cases helps. Over what pressure range this actually assists movement between brass and chamber I can't say but with/without comparisons have apparently shown it does have a beneficial effect. I don't subscribe to the claim that lubricant on the brass/chamber interface increases bolt pressure to dangerous levels.
Fire a few first with the above applied and check for the absence of any internal case thinning above the head to confirm that the cases are indeed forming without being weakened in this critical area.
It goes without saying that you should check your neck lengths and thicknesses on completion and correct these as necessary.
Annealing post-fireforming is likely to prolong the life of the cases.
A strong load for the parent case is the usual recommendation. It may have to be accepted that a sharp shoulder may take multiple firings.
There are different school's of thought on the preferred powder burn rate. I use a slow powder myself as I don't hold quantities of any fast powders. I don't think bullet weight is important so opt for cheap.
I hear cream-of-wheat is messy. Don't like the sound of it, never tried it. I also hear hydroforming is very messy and also can be hard on presses, but I like the idea in principle, certainly as a first pass to getting to 80%+ of the dimensional changes required. There are members on here who have hydrofirming dies and can advise.
Hopefully some of this is useful?

Originally Posted by zimmer

What is it you're trying to achieve/form?

Resized .270 into a new 6.5 06 chamber

Originally Posted by Bos

Resized .270 into a new 6.5 06 chamber

Ah, with that you probably will need to form a small false shoulder as per Puffin's posting. He's pretty well covered the topic.

My experience is only with forming an AI.

Which case is the longer ?
With Ackley cases they are designed slightly shorter than the parent, meaning that 2506 factory loads can be fired in a 2506 Ackley chamber as an example and headspace between the case head and end of the neck.
If your 6.5 06 cases are longer than the 270 (meaning that the chamber is longer) I would advise care.
The best most foolproof safe 'if in doubt' way for a case like you are doing with not a big necking down is as above in Puffins post, to keep screwing the die down and testing until the case just chambers with a firm bolt close. When the cases are examined they will have a bulge ahead of the original 270 neck / shoulder junction. Headspacing is between this bulge and the case head. This is a fail safe method that does not risk thinning the web.
Load the cases with a middle of the range load and go hunting. A load that is 200 fps down on max will be fine. These fireforming loads will be just as accurate as loads with formed cases.

The parent 270 case is longer so need to keep an eye on OAL.

Originally Posted by Bos

Resized .270 into a new 6.5 06 chamber

Greetings Bos,
From your above reply I assume that you have the standard 6.5-06 chamber rather than an improved version. If this is the case then sizing the neck to to 6.5 mm and trimming to the correct length is all that is needed. You can do this in a FL die, just make sure you don't set the shoulder back. Most of the advice above relates to forming to an improved chamber. You mention a new 6.5-06 chamber so I assume this has been cut by a gunsmith and hopefully is close to minimum and should match the .270 case reasonably well other than the neck. I have formed 6.5-06 cases from both .25-06 and .270 cases. .25-06 is easier as they don't need trimming but a 6.5-06 chambered in a loose .25-06 would be dangerous. A 6.5-06 chambered in a .270 is not dangerous but velocity will be low and accuracy non existent. A safer alternative.
You may also be looking to fire form your cases to fit your chamber. I suggest you may wish to do a little testing to see if this provides any measurable improvement before burning up to many components, not to mention the barrel.
Regards Grandpamac.

Thanks to everyone for the advise and help - much appreciated
With a forum like this, who needs google!!

I was looking at doing an ai chamber and think I would go for the shotgun powder and was method to mostly form it

Greetings All,
I briefly had a .30-06 AI back in the 1980's and thought it might be useful to share how the cases were fire formed. AR2206 powder was used behind the 144 NATO projectile but for some reason I neglected to record how much. Probably it was a mid load for the standard .30-06 or about 47 grains which fireformed the cases well. Later loads in the fireformed cases with 60 grains of AR2209 behind the 165 grain produced 2,830 fps. This was an old lot of powder and current production is faster. The rifle was a Parker Hale 1200TX that was rechambered from .308 so there was no need to set back the barrel. Where a rifle is rechambered from the original cartridge to an AI version best practice is to set the barrel back a couple of threads so the cases can headspace on the neck shoulder junction. This reduces stretching on the fire forming load. AI chambers are shorter to the base of the neck than their parent cartridge chambers for this reason.
Regards Grandpamac.