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Old 02-27-2019, 03:29 PM
Oso Polaris Oso Polaris is offline
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Default Fire Forming - 80% Mthod (Cream of Wheat)

I have read a number of fire forming posts using either the Direct Method (fire a fully loaded rifle cartridge) and the 80% Method (aka Cream of Wheat). I purchased 2,000 cases of Lake City virgin brass to fire form for a couple of rifles based on exact same chamber. This is a high enough round count that I didn't want to eat up that much barrel life so I decided to do the extra work fire forming with the 80% Method (Cream of Wheat). Since I am in the South, I opted to use Cornmeal.

For those of you that have been doing this for years then go ahead and stop reading...this is old hat. However, for Newbies doing this the first time I have spelled out the steps that I took. There is nothing ground breaking...I just used a few more words to describe the process.

After forming +750 cases using the 80% Method (partial fire-forming) these are my lessons learned:

1) 8.0gr Bullseye, square cleaning patches cut in 2 pieces, and cornmeal. A thin tapered chopstick is a great tool for this entire process. I tried different volumes of Bullseye powder and found no reason to use a charge greater than 8.0gr of Bullseye. (This has been proven out by everyone before me...I confirm). Remember - this is still a stout charge for pistol...it is loud so don't think that you can shoot this in the garage....or into a trash can.

Update: I used a Chargemaster to throw the 8.0gr charges of Bullseye, which gave me just enough time to seat the partial patch into the case that I had just filled before it threw the next powder charge. However, the beeping is annoying and it is slow going. I did some tests and determined that a 9mm case loosely filled to the top of the case is approx. 8.0gr of Bullseye. Add a wire handle and you have a very handy too to expedite this process, and no one will complain while you're watching a movie with the family. Nice throwback reloading tool.

2) Add powder to case and then stuff the partial patch (folded over in half... technically 1/4) on top of powder at bottom of the case. Patch keeps the powder together and close to the primer while also separating it from the cornmeal. I pushed the patch into the case most of the way down, but not all the straight to the bottom of case. Out of concern for displacing the powder from the flash hole, I was careful not to force the patch straight down. Instead, the last bit of depth I angled the chopstick down along the outside edges of the case with the goal of keep the powder mounded up in the center of the case.

3) Add Filler (Cream of Wheat, Cornmeal, etc) to case. Gradually pour the cornmeal into the case, which allows it to naturally spread and completely fill the case body without the need for tamping or compacting it with a tool. Leave the funnel on the case throughout this part to help avoid spills. Fill case all the way to top of neck (loose fill). Finally, fold remaining partial patch in half and jam into the end of case, which will provide all of the downward compression on the cornmeal filler. The top of the patch should come to rest somewhere between shoulder and half way up neck of case.

Update: Formed 1000 cases and only had 5 failed to fire. When I disassembling these failed cases I observed that the Cornmeal was extremely packed tight and overly-filled in the case, and the patch at the bottom separating the powder and cornmeal had minor burnt area. My suspicion was that too much downward pressure compacting cornmeal in the case displaced the centered powder mound causing a failure of ignition....primer functioned but not sufficient fuel in correct place for ignition. In all cases I was able to reload the case and it fired on the 2nd attempt.

4) Use simple cornmeal or corn bread mix. One small bag of Martha Stuart's cornbread mix will fill 250 cases of 223 Remington.

Update/revision: Buy canister of plain cornmeal (no other ingredients). It pours easily into the case without any need to pack/compress it into the case. Also, it burns cleaner without any residue during fire-forming. A quick shot of compressed air in the chamber between each shot blows out any remains of burnt cornmeal or patch. I realized that if there is any sugar in the prepackaged cornbread mix then it has tendency to burn and create additional buildup in chamber at mouth of case. Not terrible, but just a bit more cleanup.

5) Although Southern-style fishfry (cornmeal based) may smells better when fired, it also includes other spices in the mix. Most notably is Cayenne Pepper, which blows back in your eyes if there is any wind. I miss the scented air, but my eyes not burning won out. Use straight, plain cornmeal....

6) Buy a couple of cans of Compressed Air, which is designed to blow out keyboards and dust (buy it at any major). After each shot simply give a short blast to clear out chamber of any debris that might have spilled out of case neck when extracting the fire-formed case. The tail-tail signs of a potential issue was small indentation(s) on the newly fire-formed case, which resulted from patch/cornmeal residue from the previous shot case being pinned between chamber wall and next case to be fire-formed. I also kept an eye on the neck/mouth of fired cases to determine is any buildup of residue was occurring.

If I sprayed out chamber between every shot I only needed to clean rifle every 50 shots or so. One can of Compressed Air was good for 300 fire-formed cases. At one point I ran out of compressed air and had 15 cases left to fire-form. I needed to run a patch down barrel after every other shot to ensure no debris...this took a lot of time. Compressed Air was a huge time saver and ensured consistent results.

7) Oh yeah...wipe off each case before loading into rifle to remove any small particles of cornmeal that might be stuck to outside of case.

8) When at range firing you may have the occasional round that doesn't go off. Simply lift the bolt up and back down (i.e. re-cock the gun without partially extracting the bolt and case from the chamber... moving the bolt backwards) and pull the trigger again. On rare occasion I had to re-cock a second time and fire. If after the 3rd attempt it doesn't work then chalk it up as a primer issue and set the case to the side.

Last edited by Oso Polaris; 03-17-2019 at 12:35 AM.
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Old 02-27-2019, 03:37 PM
SmokinJoe SmokinJoe is offline
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What are you forming specifically?
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Old 02-27-2019, 04:53 PM
Daryl Daryl is offline
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As for using bullseye in the .17AH for forming, I think it was 3.5gr.
Foxhunter will quite likely know the exact amount. I think there might have been a pinch of kapok or dacron on the powder, then fireform - no bullet. Perfect results. If not enough powder, the shoulders might split. Another .2 or so gr. of bullseye and perfect results.

Then I found my new Pac-Nor 9" twist 3-groove shot as accurately when fireforming with full loads, as it did afterwards.
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Old 02-28-2019, 04:07 AM
Oso Polaris Oso Polaris is offline
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Quote:
Originally Posted by SmokinJoe View Post
What are you forming specifically?
Sorry (key detail) - I was forming 223AI.
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Old 02-28-2019, 04:24 AM
georgeld georgeld is offline
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The few cases I FF'd I used a square of TP.
To save drawing the cops by for the shooting in town
I stuck a 2" x 10' section of pvc in a hole and fired down that.

Later I found a full load worked much better and fully formed
the case.

When I got into the .358RUM FF. I used 10gr Red Dot I have 15lbs of and
will never live long enough to use up. And a 158gr cast .38 slug.
I have a bullet trap in the shop and it's now enclosed. Just sit on the step and
fire into that til I get tired and quit til next time. This way I can recycled the lead "again". Fully formed cases too.
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Old 03-01-2019, 05:03 AM
Oso Polaris Oso Polaris is offline
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Default Impact on COAL

I was forming cases for a 223AI and a 6x45AI. The reamer built for the 6x45AI was based on the chamber in the 223AI. When doing the reamer design I was concerned about changes to case length resulting from blowing out the case body and shoulder when forming the AI cartridge and also necking-up the case from .223 (.224") to 6mm. Based on new Lapua .223 Remington brass (1.750" on average from factory), I ran a series of tests to determine the impact on COAL.

1) Direct Method (load & shoot) resulted in 0.013" decrease in case length.
2) 80% Method (Cream of Wheat) resulted in 0.005" decrease in the initial forming, and then after 2nd firing with bullet to form 100% case the total overall decrease was only 0.007" in case length.
3) Necking up case from .223 (0.224") to 6mm resulted in 0.003" decrease in case length.
Note: Direct Method resulted in final case length for 6x45 AI of only 1.735" (really short)


80% Method takes 2x as much effort to form cases because doing the initial partial formation using a reduced load and cream of wheat, and then the second shot is full regular loaded cartridge. Whereas, the Direct Method only requires one loading to form the case. That said, the 80% Method has a huge time savings during the fire forming at the range. The initial reduced loads allow you to fire at a steady rate (1 shot every 30 seconds) without concern for overheating the barrel... no real need to take breaks for barrel to cool off like when shooting full loads.

I was willing to do the extra work in order to maximize the case length, reduce barrel wear from forming 2k-3k cases. Additionally, under 80% Method the initial case forming achieves almost all of the case capacity increase with minimal cost ($100 components to form 1k cases), with the second firing being conducted with final cartridge components for load development and precision shooting. I was planning to use heavy premium bullets in these rifles. If I had elected the Direct Method I could either utilizes inexpensive rounds for the initial fire forming ($300 per 1000 cases) or use my premium components ($450). In both instances the powder charge would be less than the higher powder capacity of the AI cartridge, which made it not very cost effective for my purposes. However, if my cartridge load was based on a light bullet (40gr - 55gr) then the Direct Method would be the best choice for case forming. Based on my round development (70gr - 80gr bullets), the Direct Method would not be very effective for my final load development.

Last edited by Oso Polaris; 03-02-2019 at 03:44 PM.
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Old 03-01-2019, 12:47 PM
JSH JSH is offline
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I guess I am lost here. One spends $XXXX amount, builiding then we pinch penny’s on fire forming?

I have had mixed results with the COW, even when annealed and a false shoulder is done.

I do no more case prep than I have to on fire forming. Cases will grow uneven more times than not.

As to the 6x45AI/6-223AI/6TCU I have formed several thousand in TC and XP platforms years ago. The fire forming load is not all that bad of an accuracy load. Found this to be true on quite a few cartridges7-30, about every AI I ever played with, all the TCU family, 6.5-284,30-284 just to name a few.

If one is really not wanting to fire in the barrel to keep wear down, look at some of the guys that do the hydro forming.

I myself won’t fire any more abrasive stuff down my barrel that doesn’t need to be. Steel is harder than corn cob,COW etc. To eachs own it’s not for me. If I am going to prime and load it’s going to have a proper projectile in it.
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Old 03-01-2019, 01:57 PM
flyrod flyrod is offline
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Quote:
Originally Posted by Oso Polaris View Post
I purchased 2,000 cases of Lake City virgin brass to fire form...
Thanks for posting your process and results. If I were going to form that many cases I think I'd use a hydro die.

I made a bunch of 243AI cases from 308 and 243 brass and they always ended up pretty short. I think a hydro die would've helped some, but I finally switched to 30-06 brass. It was more work but I had a full shoulder before the first firing and the cases ended up at the length I wanted. Plus it's kinda fun to hand someone a case when they ask what you're shooting.
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Old 03-01-2019, 02:19 PM
SEM SEM is offline
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Or you could be DUMB like me and buy Starline's blank 223 brass and work it down (WORK!!!!) no real need then to worry about fire forming, The main reason I go this painful route is the final case is usually full chamber plus in length, Normally a 223 case necked up to 7 TCU ends up being .070 short of the actual chamber length when using FC new brass or any other that is trimmed previously, I currently have seven TCU chambering's the shortest chamber is 1.770 and the longest 1.797 most 223 cases end up at 1.720 to 1.730 from a starting length of 1.750 to 1.760, with the Starline brass I always have to trim depending which caliber is the final stop the cases can end up as long as 2.008 of course that can vary a bit depending what the batch of cases starts at to begin with, Hope this makes sense to you and you give it a try so I'm not alone

forgot to mention I trim to .002 less than chamber length and usually end up .004 to .005 short of after firing the first time


ok flyrod you type faster than I do same same, start longer

Last edited by SEM; 03-01-2019 at 02:52 PM.
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Old 03-01-2019, 04:10 PM
JSH JSH is offline
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^^^^^
Why a lot of people tried to get me to use 222 mag. Even in the 80’s the stuff was scarce.

TC had good cartridges and then messed up the chambers, or they were not nearly as good as they could have been. I just trim to an equal case length and go on. I started annealing after every 3-4 firings did a fair bit for accuracy, just did the necks and tried to stay away from the shoulder.

My 6TCU project I am hoping all will work well with the virgin LC 18 brass. It looks as good as Lapua. There was some BS at accurate shooter on the LC brass.
Jeff
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