Fire-Forming Dasher Brass with Pistol Powder
Forum member Skeeter has a 6mm Dasher falling block varmint rifle. The Dasher case is based on the 6mm BR Norma cartridge with the shoulder blown forward about 0.100″ and out to 40°. This gives the Dasher roughly 3.5 grains added capacity compared to the standard 6BR.
Last year, Skeeter needed to form 300 cases for varmint holiday. Skeeter decided to fire-form his brass without bullets. This method avoids barrel wear* and saves on components. There are various ways to do this, but Skeeter chose a method using pistol/shotgun powder, some tissue to hold the powder in place, Cream of Wheat filled to within an 1/8″ of top of the neck, and a “plug” of tissue paper to hold it all in place. Shown below are cases filled with a pistol/shotgun powder charge topped with Cream of Wheat and then a tissue paper plug.
To ensure the case headspaced firmly in his Dasher chamber, Skeeter created a “false shoulder” where the new neck-shoulder junction would be after fire-forming. After chamfering his case mouths, Skeeter necked up all his cases with a 0.257″ mandrel (one caliber oversized). Then he used a bushing neck-sizing die to bring the top half of the neck back down to 0.267″ to fit his 0.269″ chamber. The photo below shows how the false shoulder is created.
After creating the false shoulder, Skeeter chambered the cases in his rifle to ensure he could close the bolt and that he had a good “crush fit” on the false shoulder, ensuring proper headspace. All went well.
The next step was determining the optimal load of pistol powder. Among a variety of powders available, Skeeter chose Hodgdon Titewad as it is relatively inexpensive and burns clean. The goal was to find just the right amount of Titewad that would blow the shoulder forward sufficiently. Skeeter wanted to minimize the amount of powder used and work at a pressure that was safe for his falling block action.
Working incrementally, Skeeter started at 5.0 grains of Titewad, working up in 0.5 grain increments. As you can see, the 5.0 grain charge blew the shoulder forward, but left it a hemispherical shape. At about 7.0 grains of Titewad, the edge of the shoulder and case body was shaping up. Skeeter decided that 8.5 grains of Titewad was the “sweet spot”. He tried higher charges, but the shoulder didn’t really form up any better. It will take another firing or two, with a normal match load of rifle powder and a bullet seated, to really sharpen up the shoulders. Be sure to click on the “View Larger Image” link to get a good view of the cases.
The process proved to be a success. Skeeter now has hundreds of fire-formed Dasher cases and he hasn’t had to put one bullet through his nice, new match-grade barrel. The “bulletless” Cream of Wheat method allowed him to fire-form in a tight-necked barrel without neck-turning the brass first. The only step now remaining is to turn the newly Dasher-length necks down about .0025″ to fit his 0.269″ chamber. (To have no-turn necks he would need an 0.271″ or 0.272″ chamber).
Skeeter didn’t lose a single case: “As for the fire-forming loads, I had zero split cases and no signs of pressure in 325 cases fire-formed. Nor did I have any misfires or any that disbursed COW into the action of the firearm. So the COW method really worked out great for me and saved me a lot of money in powder and bullets.” To learn more about Skeeter’s fire-forming process, read this Dasher Fire-Forming Forum Thread.
*Skeeter did have a fire-forming barrel, but it was reamed with a .269 chamber like his 10-twist Krieger “good” barrel. If he fire-formed with bullets, he would have to turn all 300 necks to .267″ BEFORE fire-forming so that loaded rounds would fit in the chamber. Judging just how far to turn is problematic. There’s no need to turn the lower part of the neck that will eventually become shoulder–but how far down the neck to turn is the issue. By fire-forming without bullets now he only has to turn about half the original neck length, and he knows exactly how far to go.
Similar Posts:
- Forming Dasher Cases with Pistol Powder
- How to Fire-Form Dasher and BRX Brass without Bullets
- How to Fire-Form Brass without Bullets
- 6mm Dasher Basics — Bob Hoppe Talks about Loads
- TECH TIP: Form Improved Cases with Hydraulic Forming Die
Tags: 6mmbr, Dasher, False Shoulder, Fire-Forming, Lapua, Pistol
Thanks to Skeeter for doing a very thorough test.
Skeeter may find if he were to put his rifle in a vice with the muzzle pointed up. He could fire form without the cream of wheat and tissue. He might try TrailBoss also. I have done it with light charges of Bullseye but doubling a load could become disasterous.
Nat Lambeth
No barrel wear?? Fire is fire, and pistol powder burns even hotter than rifle powder, so you can sure bet there will be some wear!!!! Good article though. Lee
EDITOR: Lee, you’re right, there is still hot flame and gas, but remember one is looking at about eight (8) grains of pistol powder vs. 30+ of rifle powder with this case. Also the article states the process “avoids”, i.e. reduces barrel wear. It doesn’t claim this eliminates barrel wear.
1. Do NOT use INSTANT CoW, use the “Original 2 1/2 Minute” product – image at the top of this product page http://www.bgfoods.com/creamofwheat/cow_products.asp
2. IMHO a much better “plug” is the NECO P-wad. No concern about the paper coming out on the way to the range, or in storage waiting an opportunity to fire form, or the time to rip and wad up the paper. You also need their insertion tool. Work GREAT! Link – http://www.neconos.com/category/Reloading-Aids-16
3. Also, you’ll want to bend a heavy paper clip at an appropriate angle to reach the inside of the case at the shoulder. Run the paper clip wire over the interior shoulder area to remove any fire formed CoW residue.
4. All the above from edlongrange per my personal experience with 300 6.5×47 Lapua cases AND the generous knowledgebase of one Lynn Dragoman, Jr. Thanks Lynn!
The only comment I have is that if you are not shooting bullets, then you need to use the false shoulder method, but that over works the neck metal a lot (i.e. expanded way up, then resized way back down again to create a false shoulder) and that is not ideal for the brass. I do not use the false shoulder method, and if you can use fire forming rounds for practice, match shooting, hunting, or some other purpose, then I would not use the false shoulder method (unless there is another compelling reason why it is necessary, and sometimes there is).
Robert Whitley
If you want 100 percent success and no reject cases during your case forming with “0” barrel wear.The hydralic forming process is the only way to go.This process re-locates the brass used in the shoulder area on the formed case from the case mouth every time.And there are no breakfast products utilized.There are no powder,bullets,primers used either.The formed case water capacity runs in the 99% range.The formed cases are .005-.010 long at the datum which is corrected using your full lenght die to obtain .001-.002 loose fit in your chamber.If you have questions please contact me.This process works on almost any improved cartridge.
Trevor Rosencranse
This method would be my choice of fireforming if I lived in the middle of a big city with no access to a firing range nearby. But I don’t like how far it moves the brass, and I’d still want a dedicated fireforming barrel for the job. “Sandblasting” COW down my match barrel to save a few bucks on bullets makes no sense to me. Bullets are made of guilding metal and your barrel is meant for them. COW is rough and abrasive. It belongs only in a fireforming barrel in my opinion. But if you’re going to get a fireforming barrel, why not just shoot bullets anyway and save your brass from all the stress?
Editor: All good points you raise. But one other advantage of no-bullet fire-forming is that you can neck-turn AFTER fire-forming, even if you have a tight-neck chamber. For a case like a Dasher, than makes the neck-turning operation much easier.
Since he has a barrel to fire form with I would chamber it with a no turn neck. I would use the cheapest bullets I could get, like the dog town specials. This would do away with all this extra work and clean up.
Always been a big fan of having a designated “fun-gun” made from a used up barrel for forming cases. I feel if you’re gonna pop primers someone may as well have fun doing it. Just have your kids and their friends over for a competition and some fun target shooting. You supply all the ammo loaded with cheap bulk bullets and next thing you know the work is done and a few kids from the neighborhood had fun (you look like the coolest parent ever) and they are quick to remind you to “call me if you ever need any cases formed again!”
This concerns the comment: ” ‘Sandblasting’ COW down my match barrel to save a few bucks on bullets makes no sense to me. Bullets are made of guilding metal and your barrel is meant for them. COW is rough and abrasive. It belongs only in a fireforming barrel in my opinion. But if you’re going to get a fireforming barrel, why not just shoot bullets anyway and save your brass from all the stress?”
Where are the FACTS & VALIDITY on the “Sandblasting” COW (Cream of Wheat)????
Creme of Wheat does NOT register on any hardness scale.
I want some PROOF that “COW” has as “Sandblasting” and abrasive of an effect that kb2051 says there is….
IMHO “COW” has as negligible effect compared to the powder temp on the steel when being fired.
After just fireforming 200 cases for my new .2704″-necked no-turn 6 Dasher, I can say that loading up virgin, unsized Lapuas with 30.5gr of Varget with a 108BT jammed .030″ gave me 200 perfectly formed cases.
Overworking the brass or firing cereal were not considered, though I know it works for some.
I had no problem with COW with my 6.5×47 loads but when I went to a similar setup with a 6.5-300 RSAUM Improved I destroyed the necks of at least 25 % – burned chunks out of the sides. Hard to tell what the problem was (possibly too light a load) but with junk bullets I’ve had zero problems. Going forward I’ll go with junk bullets – and my fireforming barrel.