Cream of Wheat forming question

[Brians356]

18 years ago I paid for a lathe and a 257 Roberts Ackley reamer. I used a piece of 257 Roberts virgin brass as the go gauge. The firing pin pushed the case forward, the sharp ring at the base of the chamber neck stopped the brass after cutting into the brass, the pressure caused the case walls to grab the chamber walls, the pressure pushed back on the case web, and the brass stretched.

I tried ~100 ways to form the brass to fix this problem. Back then I was the highest paid and lowest IQ electrical engineer consultant around. I often solved problems empirically.
I settled on 10 grains of any pistol powder covered with a case full of instant cream of wheat. That formed half a shoulder, that would stand up to the firing pin on the next firing. The next firing could be full power and full accuracy. That light varmint Walther Lothar barrel on a VZ24 shot a 0.45" 5 shot group at 100m.

But Dusty Stevens has been making posts so smart and succinct ... maybe I should try paper towels.

For bulletless forming: If you wet the case body with a scant film of Kroil or Rem Oil, your cases would have lodged firmly against the boltface and prevented web stretch. Also not sure you headspaced the chamber for a crush fit on the Roberts case, typically .010 shorter than the parent chamber, I've read some guys just come in a full turn of the barrel.
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[Brians356]

I think Trail Boss would be a better bet. As it's a big flakey powder it almost acts like a filler and gives a big case fill. I have used it in a 6 PPC and a Shehane but I was using cheap bullets.

Like everyone else I'm not even going to hazard at a guess for your purpose.

Trail Boss is inappropriate for fireforming, with or without a bullet.
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[Brians356]

I nearly blew coffee out my nose on that one Dave. Thanks, I needed that today.

Incidentally, you can obtain TP at WallyWorld during "senior hour" on Tuesday mornings one hour before normal store opening. But you'll have to propel your wheelchair quickly to stay abreast of the rush, and better wear your facemask as they'll be jostling and respirating vigorously.
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[INTJ]

9 grains in a 6 br isn’t 70%
Wayne

Yes but 20 grains is and that is what I used, held in place by 1/8 piece of toilet paper. I give all the details in my post.

 

[bozo699]

Yes but 20 grains is and that is what I used, held in place by 1/8 piece of toilet paper. I give all the details in my post.

I got interrupted and never finished that sorry. Yes I liked your post
Wayne

 

[Elwood]

Trail Boss is inappropriate for fireforming, with or without a bullet.
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Any particular reason? I know of a few people using it for this purpose.

 

[Brians356]

Any particular reason? I know of a few people using it for this purpose.

Assuming we're discussing "improving" a case (blowing out the body and forming a new shoulder) conventional wisdom (not always fail safe!) prescribes either a fast, hard spank "bulletless" using pistol powder (and pistol primer), or a "stiff" published load behind a bullet. Your post is the first I've heard Trail Boss mentioned for such. It seems antithetical on its face, since even a case full of Trail Boss produces relatively mild pressure by design. But I've been dead wrong at least once before.

 

[Elwood]

Assuming we're discussing "improving" a case (blowing out the body and forming a new shoulder) conventional wisdom (not always fail safe!) prescribes either a fast, hard spank "bulletless" using pistol powder (and pistol primer), or a "stiff" published load behind a bullet. Your post is the first I've heard Trail Boss mentioned for such. It seems antithetical on its face, since even a case full of Trail Boss produces relatively mild pressure by design. But I've been dead wrong at least once before.

Ok thank you for your reply.
I'm far from being a expert on the matter and my knowledge on using Trail Boss was given to me by a rather good Aussie F class shooter, he's a member on here.
My first experience with Trail Boss was with fire forming .284 Shehane, I'd say that was a pretty easy test as we are only talking about moving the case walls 5 or 6 thou out either side. I then used it to form 6ppc with I think good results, not having anything to gage it against. Lastly I tried it in a .284 KMR which is moving the case walls out and changing the shoulder angle, so a tougher test, which it passed.
Before using Trail Boss I had always used Unique or Bullseye to fire form Shehane and 6mm AI. The two main advantages to Trail Boss are there's no reason to use a filler and it's extremely cool burning, so much so that in my last KMR I used it for 50 cases to fire form and run the barrel in.

 

[Clark]

For bulletless forming: If you wet the case body with a scant film of Kroil or Rem Oil, your cases would have lodged firmly against the boltface and prevented web stretch. Also not sure you headspaced the chamber for a crush fit on the Roberts case, typically .010 shorter than the parent chamber, I've read some guys just come in a full turn of the barrel.
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I left out a step. I put a film of moly grease on the cases.
My father [chief engineer for 40 years while pounding on tables and yelling] called it "Fifty thousand psi grease".

 

[Ccrider]

Work up slow. You can use too much pistol powder. Ask me how I know.
Also, the amount of powder used will change depending on your filler. I have used clay and paper towel. The paper towel works fine and is easier to clean out of your barrel. I could not talk myself into trying COW.

 

[real cowman]

Anyone ever use rifle powders to form cases? I need to form some cases and don't have any pistol powders. I have several rifle powders that I don’t hardly use. Yes I could just shoot bullets Like I usually do, but I am stuck at home. Any Ideas

 

[Brians356]

Work up slow. You can use too much pistol powder. Ask me how I know.

How you know?
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[Brians356]

Anyone ever use rifle powders to form cases? I need to form some cases and don't have any pistol powders. I have several rifle powders that I don’t hardly use. Yes I could just shoot bullets Like I usually do, but I am stuck at home. Any Ideas

I'm loath to suggest anything not published formally, but do you have any H4895? Hodgdon declares it safe for reduced loads down to 60% of published max charges for each particular combination. So it follows in my fallow mind that you might use 60% without a bullet. With a wide open case mouth and no filler, there's a rather generous pressure relief valve. Me? I would pull the first trigger with a long lanyard, but I'm superstitious.
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[Ackman]

Anyone ever use rifle powders to form cases? I need to form some cases and don't have any pistol powders. I have several rifle powders that I don’t hardly use. Yes I could just shoot bullets Like I usually do, but I am stuck at home. Any Ideas

Yes I've always used rifle powders to form AI cases. With bullets. I've posted several times about this. Don't understand why people screw around with fillers unless maybe they're just horny to make something go bang. But it's real simple, and I'm talking about IMPROVED cartridges. The improved chamber is larger than a std. chamber, so when firing a standard case in an Improved chamber the thing expands quite a bit. A max load for the std. case is a light load when shot in an improved chamber. Start with the accuracy load for the std. cartridge and do a load work up like with any other cartridge. Stop at the most accurate. And of course be watching for overpressure. The accuracy load will be somewhere between a max load for the std. chambering and what you'll be shooting with formed brass. That fireforming load will be faster than standard and just as accurate. So it's a working load that's faster and with the bonus of producing a perfectly/completely formed Improved case. A total win-win, there's no downside.

 

[Brians356]

Yes I've always used rifle powders to form AI cases. With bullets. ... So it's a working load that's faster and with the bonus of producing a perfectly/completely formed Improved case. A total win-win, there's no downside.

Some of us consider consuming bullets to fireform a downside, and there's arguably more barrel wear as well. Plus you're consuming a lot more powder, all of it rifle powder. You're also doing more load development which takes time. The argument that the fireforming loads are just as accurate as the final loads, and therefore not really wasted, assumes several particulars about the individual's intents. If someone only wants to hunt or compete with the final highly-tuned improved load (probably most folks here) then it's a benefit in search of a need. I want to form my Ackley Improved cases as quickly and mindlessly as possible, using the least components, subjecting the barrel to minimal wear, so I can begin load development in earnest. But I'm selfish like that.
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[real cowman]

I agree with you completely. I am forming 257 Roberts ackley improved and normally just use a fire forming load With 75 gr vmax bullets that I use on coyotes. However, I am stuck at home and would like to load some bullets and would like to form some cases and all I have is rifle powders.

 

[bozo699]

Yes I've always used rifle powders to form AI cases. With bullets. I've posted several times about this. Don't understand why people screw around with fillers unless maybe they're just horny to make something go bang. But it's real simple, and I'm talking about IMPROVED cartridges. The improved chamber is larger than a std. chamber, so when firing a standard case in an Improved chamber the thing expands quite a bit. A max load for the std. case is a light load when shot in an improved chamber. Start with the accuracy load for the std. cartridge and do a load work up like with any other cartridge. Stop at the most accurate. And of course be watching for overpressure. The accuracy load will be somewhere between a max load for the std. chambering and what you'll be shooting with formed brass. That fireforming load will be faster than standard and just as accurate. So it's a working load that's faster and with the bonus of producing a perfectly/completely formed Improved case. A total win-win, there's no downside.

Not being rude at all as I agree with your methods of fire forming with bullets but the op wants a method for bulletless fire forming on a very large caliber cases. I as well do not like cow it’s way to messy and need a air compressor to clean out between each shot or at least in my experience I have however had good luck just holding gun upright ,... butt stock down with pistol powder and a patch the question is how much pistol powder would be suitable for that large of case. @ITNJ Seems to think 70% and he may be right but that sounds like a lot to me as that may be as high as 85 grains or so which sound like way to much to me but again I only have experience with much smaller cases.ITMJ WAS USING 20 gr on a br case I believe I used 12. When I get the chance I’m going to try blowing out my .338 Lapua imp. So I know but it would be nice if there were some hands on with large case experience
Wayne

 

[Brians356]

I agree with you completely. I am forming 257 Roberts ackley improved and normally just use a fire forming load With 75 gr vmax bullets that I use on coyotes. However, I am stuck at home and would like to load some bullets and would like to form some cases and all I have is rifle powders.

You can fireform at home? You're literally stuck there?
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[Ackman]

Some of us consider consuming bullets to fireform a downside, and there's arguably more barrel wear as well. Plus you're consuming a lot more powder, all of it rifle powder. You're also doing more load development which takes time. The argument that the fireforming loads are just as accurate as the final loads, and therefore not really wasted, assumes several particulars about the individual's intents. If someone only wants to hunt or compete with the final highly-tuned improved load (probably most folks here) then it's a benefit in search of a need. I want to form my Ackley Improved cases as quickly and mindlessly as possible, using the least components, subjecting the barrel to minimal wear, so I can begin load development in earnest. But I'm selfish like that.
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Yes load development takes time. Finding the right "fireform" load IS load development in earnest. It's finding what the gun likes. Then with formed cases it'll be nearly the same, maybe a 1gr or so more. Hardly anything. I'd much rather put bullets down a barrel and be shooting things than wasting primers, powder, and time then putting crap down the barrel that won't shoot anything, many times getting an incompletely formed case, then later having to clean crap out of the barrel.

I've formed roughly 5,000 rds of AI cases in several guns and except for load workup, all of them in the field with great accuracy on furry targets.

Example: Best ever accuracy/velocity 22-250 load for me is a 50 doing 3925 with 37.5gr powder in one factory sporter. AI 50gr. fireforming loads in a couple other guns was about 1gr more of the same powder, doing a bit over 4100. These loads were definitely "in earnest." Then formed cases, another .5-1.0gr same powder and bullet at about 4200 and considerably more than that. Those "fireform" loads dispatched a whole load of varmints. Similar results in 17AI Hornet, 223AI, 243AI, 257AI.

 

[INTJ]

Yes load development takes time. Finding the right "fireform" load IS load development in earnest. It's finding what the gun likes. Then with formed cases it'll be nearly the same, maybe a 1gr or so more. Hardly anything. I'd much rather put bullets down a barrel and be shooting things than wasting primers, powder, and time then putting crap down the barrel that won't shoot anything, many times getting an incompletely formed case, then later having to clean crap out of the barrel.

I've formed roughly 5,000 rds of AI cases, and except for load workup, all of them in the field with great accuracy on furry targets.

I am not willing to burn up 200 rounds of good barrel life on a competition barrel that may only last 1000 rounds and one season. That is what forming with bullets does for my 6 BRA.

Finding a competitive and well-tuned load that would allow taking unfired cases to a match would be an exercise in futility. Chances are that by the time the load was tuned to my satisfaction I wouldn't have enough unfired cases to cover the match, so I would also need a tuned load for the fired cases. It's much better to use the exceedingly simple and reliable 20 grains of Bullseye and 1/8 sheet of TP for when a fireforming barrel is not available.

In a hunting rifle that needs only 50-100 cases and won't shoot 1000 rounds in 20 years, it doesn't matter.