Fire Forming No Bullet

[steve4102]

I would like to fireform a bunch of 7.62x39 brass to 6.5 Grendel without loading a bullet. What's the best and most effective way to fireform bullet free?

Thanks
Steve

 

[PT1911]

I was under the impression that you needed the added pressure of bullet resistance to fireform effectively... I have never read or heard this... I suppose i just assumed it... Perhaps i am wrong about that.

 

[JDGray]

Don't know how your gonna do that, without sealing the pressure in the chamber Maybe a snug fitting wooden dowel down the barrel, and a mag primer?

 

[earplug]

I have seen it done with clay

Shooter was forming 223 Ackley Improved. He was using some sort of clay.

 

[Robert Wilson]

I've also known of people doing it with wax. The idea is to charge a case with a small amount of fast pistol powder, then jam a block of paraffin into the case mouth to form a plug. I've never done it and don't plan on trying, but there you go.

 

[orrwdd]

I've also known of people doing it with wax. The idea is to charge a case with a small amount of fast pistol powder, then jam a block of paraffin into the case mouth to form a plug. I've never done it and don't plan on trying, but there you go.

Sounds like an iffy thing to me. I am not sure you could generate enough pressure that way. I would much rather load a standard round and fireform on the first load.

Bill

 

[Robert Wilson]

Me too.

 

[steve4102]

Found it thanks.

by Dr. Kenneth Howell in his book designing and forming custom cartridges.

He recommends starting with the 10% rule
Take the parent case with a fired primer still intact
Fill the case to the top with Bullseye (or similar speed fast pistol or shotgun powder)
Pour powder onto scale and weight
Divide the total weight by 10
If for example, your total is 63.40 grains.
Your starting charge should be ~ 6.34 grains
This will fill up your parent case about 10% of it’s total volume

When ready to form, start with a PISTOL primer, NOT a RIFLE primer

Add your forming charge
Then using a small wooded dowel that will fit through the case neck, lightly tamp a quarter of a sheet of folded or wadded up toilet paper onto the powder at the base of the case.

Then fill the case with your inert filler material
( Cream of Wheat)
Leave ~ 0.100” of the case mouth open so you can top off the case with a retention material like lead bullet lube or paraffin wax
Just “smear” off the top and wipe away any excess around the outside of the neck

 

[ReloaderFred]

Over the years if you wanted to shoot some of the obsolete calibers, you made your own brass by fireforming. Apparently, the newer generation of reloaders haven't found this necessary, since most brass is now available. It used to be a common practice, and I've done it many times.

The material of preference in my fire forming is corn meal, since it compacts nicely and gives a good case fill out when fired. Depending on the size of the case, an appropriate charge of fast pistol powder is used and then the process as described above is performed. I dispense with the wax plug and just tamp the cornmeal until it holds itself in the case. You may find it necessary to swab the bore and chamber every few rounds, so you don't end up with dimples in your brass from left over corn meal.

Just be sure to shoot up in the air, as there is quite a bit of pressure produced and the resultant blast is dangerous, just like shooting blanks.

Hope this helps.

Fred

 

[yooper_sjd]

You can fire form a ctg. But you need some kind of resistance to retard chamber pressure. try just shooting a wax bullet. western style shooters shoot them all the time. Can make one out glue sticks, bee wax, or potters clay. You can even use a blank shooting adapter as well.......just need something that will keep some back pressure in the tube to form out ctg.....

 

[SpamHandler]

I typically use a wadded polyester plug to keep the corn meal (I've also used coffee grounds on occasion), in place. The only problem I've encountered is a yearning for breakfast what with the smells of corn muffins and hot coffee in the air....

 

[esheato]

I did...ohh, about 2,000 rounds of 223 AI a few years ago.

I believe I used Unique over a pistol primer with a corn meal filler and a TP plug to hold it all in the case. Take a quarter of a square, roll like a cigarette, place into top and tamp with a punch to hold it in.

Case formed well enough (read rounded versus sharp corners) to reload as the new ctg. Upon firing a full power load the corners filled out.

 

[Curator]

Full length size your new brass in the 6.5Grendl die, prime, load 4 to 6 grains of bullseye and fill hhe caes to the mouth with cornmeal or cream of wheat cereal (better). Stick case mouth into a block of parafin wax or soap to keep the stuff inside. Lightly oil the case mouth and shoulder, load, aim up and fire. Cases will come out just about perfectly fireformed. You will look like you were in a cereal shower.

 

[ranger335v]

I've done a modest amount of blowing cases out with a 6-7 gr. charge of Bullesye or Red Dot under a small wad of tapped down toilet tissue and fillling the rest of the case with dripped wax from a large candle. Type of primer doesn't seem to matter but do need to let the wax cool for an hour or more to insure it's not soft before blowing it out. That does a fine job for me and it's sure harmless to the bore.

 

[66stang351]

Full length size your new brass in the 6.5Grendl die, prime, load 4 to 6 grains of bullseye and fill hhe caes to the mouth with cornmeal or cream of wheat cereal (better). Stick case mouth into a block of parafin wax or soap to keep the stuff inside. Lightly oil the case mouth and shoulder, load, aim up and fire. Cases will come out just about perfectly fireformed. You will look like you were in a cereal shower.

Yep, this is what we do...amount of Bullseye varies with case size, but 4-6 should be about right for what you are doing.

 

[Sport45]

The material of preference in my fire forming is corn meal, since it compacts nicely and gives a good case fill out when fired. Depending on the size of the case, an appropriate charge of fast pistol powder is used and then the process as described above is performed. I dispense with the wax plug and just tamp the cornmeal until it holds itself in the case. You may find it necessary to swab the bore and chamber every few rounds, so you don't end up with dimples in your brass from left over corn meal.

I've formed many .30-30 cases into straight wall .375Win cases with cornmeal using ReloaderFred's quoted procedure. The only things I did different were I plugged the case mouth with bar soap (just shove the bar over the mouth and twist) and I fired into the ground 10 or so feet in front of me so any loose corn meal wouldn't fall back into the action of the '94.

Smells something like cornbread baking when you touch them off.