fire forming using Bullseye

[BJung]

I found online that you can fire form your brass by filling a whole case with Bullseye, measuring that volume by weight and loading your brass with 10 percent of the total volume. Has anyone tried this and does it work? The instructions say to do it again if your case does not expand enough. Has anyone used this recipe? Should I make it 12-15% to ensure an expansion? I'm fire-forming 30-06 to 7.7 Arisaka brass. How far will that wax plug go in distance? Thanks

[BK7saum]

For many applications, I use a starting load after forming and just go out and shoot. Usually these loads are about as accurate as anything I work up later.
I am no familiar with the 7.7 from 06 conversion, but if you are just pushing the shoulder back and adjusting neck diameter slightly, I would not waste resources fireforming.

[BK7saum]

Looking at 7.7 vs 30-06, I can't see any reason I would even attempt to fireform with bullseye.

But to answer your original question, I have fireformed with bullseye amd ended up using a filler over a few grains of BE. Start low and work up. Fireforming is very loud and generates quite a bit of pressure. Also, I had to point the muzzle straight up to get uniform expansion.

[K43]

If you just load that 10% Bullseye you will probably get ill formed or not fully formed cases. There needs to be something to hold the pressure to push the case walls/shoulder out. COW, grits, etc. It's too much mess and you're just wasting a primer to throw carbohydrates into the air. I've done it. Full case of COW with a wax wad on top. Still didn't fill out the 219 Wasp.
I just load a little more than the start loads in the pubs under appropriate projectile and go shoot. The following all need some shoulder push out and fill of varying degrees: 219 Donaldson Wasp from 30-30, 300 Savage from 308, 8x57 from 30-06, 8x56R from 7.62 Russian, and 9.3x57 from 8x57, 30-06, of 35 Whalen.
Just load a light load and go shoot.

[jdgabbard]

Yeah, most people fireform their cases with starting or below loads - depending on how much forming they need. I've heard of people doing the method you're doing, but I haven't seen any benefit to it in my experience. The only thing I have to worry about converting these days is .223/5.56 to 7.62x25. Which doesn't really require any fire forming. First couple of times you shoot the brass they'll develop a swelled out base. But that is because the case head is slightly smaller with the .223/5.56 brass compared to the Tokarev. The difference is literally the difference between the case head of a 9x19 and a .380acp. Doesn't affect anything, but is a little funny to look at....

That said, if I were you I wouldn't bother with trying to fire form with bullseye unless I had to. Just load up some loads slightly under the starting load and go from there. Looking at the difference between the two it really looks like most of the work comes from setting back the shoulder. You too will have a little bit of body swelling back towards the case head. But I'm not seeing anything to suggest needing to fireform separately.

[steveu]

I used 10 grains to fireform 280 Ross from 300 wm. Worked great, make sure you anneal the shoulder area.

[Mk42gunner]

I have always had better luck fireforming rifle brass with a moderate load and a real projectile than trying to use a fast powder and a filler such as corn meal or cream of wheat.

Given the cost of primers and powder these days, I'd rather get in a bit of target practice while fireforming.

Robert

[jonp]

I use Promo and a filler to fire form.

[muskeg13]

I've had good luck fireforming 6.5-06 AI, .338-06 AI and .35 Winchester cases using Unique, Blue Dot and 2400, using nothing quite as fast burning as Bullseye. Once you have it right, you can form dozens of cases without losing any and it goes quickly. The only down side these days is you're expending a primer and a bit of powder. The last ones I did was blowing out .303 British to .35 WCF using Blue Dot. I annealed the cases by heating the necks and shoulders in a dimly lit room with the cases standing in a pan of water. Using a propane torch, when the the necks just began to turn dull red, knock them into the water to quench. After the cases are dry, prime and charge with Blue Dot (or anything in that general burn rate). I believe I started with about 13 grains, went to 16 grains and settled on 19 grains. Start low with a few cases and see how well they blow out. After charging with powder, fill the case with cream of wheat or grits to the top and lightly push in a tissue wad (1/4 sheet of TP rolled up in a ball), just to keep the grain from spilling all over the place. DO NOT tamp down and compress the cream of wheat/grits in the case below the neck! A wax wad isn't needed.

Outside, with the muzzle pointed up, carefully chamber the cartridge and fire. If the case doesn't blow out to almost fully form, add a few grain more powder and try it again. It is noisy like shooting a blank, but the filler grain doesn't go far. Once I got the charge powder weight correct, I fired 50 as fast as I could single load. The next step was to square the necks by trimming to a consistent length, and then the cases were ready to load as normal.

[BJung]

I'm thinking of what options I can do. First, would be dangerous to handload my OCR ladder tests with the brass and save time and material. The test would run medium to hot. Another would be to assemble an OCR test string with cast bullets using 2400 or 4227. The I can use the fireformed brass. Third, if I use Blue Dot or Bullseye with tissue and filler and a wax plug, will crayons work? I was at the dollar store the other day and noticed the crayons.

[Plate plinker]

crayons are abrasive they often contain clay. AVOID

[K43]

Seems you've decided what you are going to do. Have fun.

[muskeg13]

If you're going to cap the FF loads with wax, I'd suggest using no more than a #4 buck-sized ball of soft lube. I keep the discarded lube from my lubra-sizer in bottle caps to use for general lube uses in the garage. For fire forming, you only need enough wax to hold the contents of the cartridge in place, and soft sticky lube works good for this. The wax is not used as a projectile to raise pressures and help blow out the case.

[BJung]

Wow! Thanks

[BJung]

Thanks

[K43]

There isn't necessarily a right and wrong way with some things, just things not to do when you do what you do. Like don't use Crayons, DO wear hearing protection if you do it indoors, Don't stick the muzzle in the toilet like my buddy did and crack you toilet bowl with the muzzle blast.
Just ask here and you will get a bazillion ideas to choose from.

[ulav8r]

There isn't necessarily a right and wrong way with some things, just things not to do when you do what you do. Like don't use Crayons, DO wear hearing protection if you do it indoors, Don't stick the muzzle in the toilet like my buddy did and crack you toilet bowl with the muzzle blast.
Just ask here and you will get a bazillion ideas to choose from.

Wife's response, "What a dumb jerk".

[Willbird]

For 7mm TCU which is a 223 blown out to 7mm in a TC contender one can just fire 223 ammo, the 223 bullet we would hope never touches the 7mm bore, it seems to work fine really.

[country gent]

You need a fast enough powder to generate the pressures to form the cases and you also need the gas volume to form the case some powders may not produce enough gass at the desired pressures.
Most I know who fire form use unique or similar.
The ackly improved ( most of) cartridges, the tcus and some others can be fire formed with the parent cartridge as loaded. In the case of the ackleys there is little loss of accuracy but some performance.

[Willbird]

You need a fast enough powder to generate the pressures to form the cases and you also need the gas volume to form the case some powders may not produce enough gass at the desired pressures.
Most I know who fire form use unique or similar.
The ackly improved ( most of) cartridges, the tcus and some others can be fire formed with the parent cartridge as loaded. In the case of the ackleys there is little loss of accuracy but some performance.

I have used Clays and it worked fine to blow 240 Ackley out into a 375 straight wall case. Clays, small piece of toilet paper, than filled case with corn meal, had corn meal did not have cream of wheat. This was in a device I made to fire form brass not the barrel I will be using. Just made a chamber section out of CRS and then added enough 3/4" steel tubing to be 18+" long for legal reasons.

Bill