fire formed brass
I've read and heard several times ,people speak of fire forming brass, and wonder what they are refering to. Anyone familiar with this term?
I've had a request from my opposite number over in the Reloading Forum to send these types of questions over to the guys who specialize in them.
I've had a request from my opposite number over in the Reloading Forum to send these types of questions over to the guys who specialize in them.
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Once a factory ammo has been placed & fired in your rifle / pistol, the case has fired & formed to match your chamber. Hence fire formed [;)] 0 -
Using gunpowder to shape a cartridge case to the exact configuration as your chamber.
The majority of reloaders don't bother with standardized chamberings
You could consider only neck sizing to be a "type" of fireforming.
Those who worry about it the most are those of us who are playing with wildcat and obsolete cartridges, where the shoulder shape/size/location is different than the "parent" cartridges. Example: look at a 300 Weatherby cartridge, than look at it's parent case the 300 H&H. Back when Wby brass was rare/non-existant everybody made their cases by fireforming (firing) a 300 H&H cartridge in their 300 Wby chambered rifle0 -
FIRE FORMED cases were used specifically for the Ackley improvements to such rifles as the 30-40 Krag (becoming an Ackley improved) where the neck angle of degree changed a lot. Wildcat cases such as these had no commercial availability so you had to take a 30-40 Krag and shoot it in a Krag Improved rifle and form the neck thus FIRE FORMING the neck to the new rifle. Most cracked in the process but some did not. All wildcats did this for quite some time. Fire forming has nothing to do with a shell being fired in a specific gun and then only neck sized to repeat in the same rifle for accuracy. 0 -
Joker
One slight "nit".
You can (and some do) fireform for oversize/over long "stock" chambers, followed by necksizing, simply to increase the case life. The biggest group of people that do it this way are those reloading for belted cases. This allows them to use the shoulder to control headspace.
The 30-40 Krag is kind of a bad example, as it's a rimmed case.
Woodhog
Below is a photo of the shoulder on a 243 Win (on the right) and a 243 Wade
Below are a number of wildcats that have been formed from the 30-30 Winchester
Finely, a 22-250 and a 22-250 AI which clearly show what fireforming can do.0 -
Fireforming also adds much to the future accuracy of the case for reloaders. The poorest accuracy usually occurs on the first firing of new brass whether factory loaded or handloaded. Once the case is fireformed in a good chamber, the case will perfectly fit that chamber for many loadings. The headspace will be correct allowing very little expansion and the case neck will be very straight compared to new brass. This allows only neck sizing to be needed for much longer case life and better accuracy since full length sizing is now unnecessary until chambering becomes tight. These techniques work best in bolt action rifles. 0 -
[8D] Gotta agree with Zimm, my .223 Rem 700 gets remarkable accuracy with fireformed "MATCH" cases-
quote:Originally posted by zimmden
Fireforming also adds much to the future accuracy of the case for reloaders. The poorest accuracy usually occurs on the first firing of new brass whether factory loaded or handloaded. Once the case is fireformed in a good chamber, the case will perfectly fit that chamber for many loadings. The headspace will be correct allowing very little expansion and the case neck will be very straight compared to new brass. This allows only neck sizing to be needed for much longer case life and better accuracy since full length sizing is now unnecessary until chambering becomes tight. These techniques work best in bolt action rifles.
[:o)][:o)] JIMBO0 -
Fireforming is useful for pistol cases too. The 9x18 Makarov case has a slightly larger diameter and is 1mm shorter than the standard 9x19 round. I trim the 9x19 to 18mm, load them and fireform them to get the right diameter. Cases and gun are a bit dirtier but the following reloads are not. 9x19 cases are much cheaper and easier to find than the 9x18s. 0 -
On firing, the brass expands till the chamber stops it. 0 -
quote:Originally posted by 243winxb
On firing, the brass expands till the chamber stops it.
Good explaination , but not to be done !![:0][:D]0
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