Fire forming is the idea still relevant

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AJC1

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While reading the front matter of many a reloading manual, and discussed commonly on the internet and YouTube video, the glory of fire forming is presented. As with many ideas there is, this great idea presented, which would seemingly apply unilaterally but doesn't. There are applications where I believe it provides large benefits, but they are not detailed as they should be.
1. If you neck size. Old military rifles and varmint shooters alike that practice the art of neck sizing.
2. If your going through the process of having a custom die made. Also includes neck sizing.
3. If your converting brass in a different chamber. Ackley is the most known version of this processes.

With the most common form of brass preparation being full length sizing, I can see no benefit in fire forming. The couple of thousandths between new and shoulder bumped brass seems totally insignificant. Am I missing something???
 
In most instances, virgin brass will be sized to minimum standards, which means for most chambers, it will be under sized already. So then we just run through the sizing die to make sure the neck tension is appropriate, then after fireforming, with consistent annealing, we can then know our brass will be the same size and shape upon every FL sizing from then on.
 
In most instances, virgin brass will be sized to minimum standards, which means for most chambers, it will be under sized already. So then we just run through the sizing die to make sure the neck tension is appropriate, then after fireforming, with consistent annealing, we can then know our brass will be the same size and shape upon every FL sizing from then on.
So were fire forming for the die not the chamber????
 
So were fire forming for the die not the chamber????

No.

We’re fireforming to fit the chamber, then full length sizing to ensure ammo remains to feed and fit into the chamber.

Arbitrarily, let’s say virgin brass is sized to minimum specification, which is 15. Let’s say our chamber is actually 20. We fireform to move the 15 to 20, and then we set our sizing die to 18 to ensure we’ll not have feeding issues in the future. Obviously, there is a difference in internal volume for brass which is 15 and that which is 18. But when we have 18 upon every firing because we bump the same once brass is brought up from its original, undersized state, we have consistency.
 
I fireform my brass for the rifle it is to be used in then use neck sizing or bumpimg the shoulder back each additional time to help control the growth of the brass and the resulting incipient case head seperations this causes. The less you work the sidewalls of the brass the longer it will last IMO. For semiautos I will full length size for reliability of ammo feeding. Mine are not as accurate as my bolt rifles so it does not make as much difference when I FL size.
 
We’re fireforming to fit the chamber, then full length sizing to ensure ammo remains to feed and fit into the chamber.

Arbitrarily, let’s say virgin brass is sized to minimum specification, which is 15. Let’s say our chamber is actually 20. We fireform to move the 15 to 20, and then we set our sizing die to 18 to ensure we’ll not have feeding issues in the future. Obviously, there is a difference in internal volume for brass which is 15 and that which is 18. But when we have 18 upon every firing because we bump the same once brass is brought up from its original, undersized state, we have consistency.

That's quite possibly the most understandable and simplest way to explain the process......Thanks for that.....Even a doofus like me can understand it...!...:)
 
I can see no benefit in fire forming. The couple of thousandths between new and shoulder bumped brass seems totally insignificant. Am I missing something???
I fire formed 6BR cases into 6 Dasher cases. A large difference in where the shoulder ended up.

AccurateShooter.com Pic
samhallhg08.jpg


I used to fire form .220 Russian into 6 PPC, again, quite a difference afterwards.

AccurateShooter.com Pic
220russianx300 (1).jpg

Then of course use the correct FL sizer as usual to keep them that way and fitting the chamber correctly..
 
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No.

We’re fireforming to fit the chamber, then full length sizing to ensure ammo remains to feed and fit into the chamber.

Arbitrarily, let’s say virgin brass is sized to minimum specification, which is 15. Let’s say our chamber is actually 20. We fireform to move the 15 to 20, and then we set our sizing die to 18 to ensure we’ll not have feeding issues in the future. Obviously, there is a difference in internal volume for brass which is 15 and that which is 18. But when we have 18 upon every firing because we bump the same once brass is brought up from its original, undersized state, we have consistency.

I love it when people have the knowledge and capability to be able to dumb stuff down so I understand! Thanks Varminterror!!!!
 
I fire formed 6BR cases into 6 Dasher cases. A large difference in where the shoulder ended up.

AccurateShooter.com Pic
View attachment 1061260


I used to fire form .220 Russian into 6 PPC, again, quite a difference afterwards.

AccurateShooter.com Pic
View attachment 1061261

Then of course use the correct FL sizer as usual to keep them that way and fitting the chamber correctly..
I absolutely agree and I thought I covered that under #3. Sometimes what I'm thinking doesn't convey correctly.
 
While reading the front matter of many a reloading manual, and discussed commonly on the internet and YouTube video, the glory of fire forming is presented. As with many ideas there is, this great idea presented, which would seemingly apply unilaterally but doesn't. There are applications where I believe it provides large benefits, but they are not detailed as they should be.
1. If you neck size. Old military rifles and varmint shooters alike that practice the art of neck sizing.
2. If your going through the process of having a custom die made. Also includes neck sizing.
3. If your converting brass in a different chamber. Ackley is the most known version of this processes.

With the most common form of brass preparation being full length sizing, I can see no benefit in fire forming. The couple of thousandths between new and shoulder bumped brass seems totally insignificant. Am I missing something???

I don’t think there is any disadvantage for the average reloader.
 
I'm saying with the average reloader there is no significant difference. No advantage or disadvantage.

Every reloader, average or otherwise, benefits from consistency in their process, even if it’s just to maintain a margin of safety and confidence in the ammo they shoot.

With that said, those that are ate up with the accuracy bug (*nature boy raised his hand here*) need to know they are controlling their variables in order to achieve the best load for their intended application. That’s hard to do if the brass is changing from one reloading to the next because all you’re sizing is the neck. Better to size the whole thing, each time, and keep the brass as consistent as possible from one load to the next.

I shot a match a while back while fire forming new 6BR brass into 6BRA. It wasn’t bad. I shot a 592 (52 out of 60 shots at 600 yards found the 10 ring), however, there were a few unexplained flyers, including an 8. Thank goodness too. Can you imagine the outcome if I shot a personal best with new brass? I’d either need Lapua to sponsor me or take up a life of crime to pay for the hobby. It’s bad enough as it is
 
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Benchrest preped formed brass will produce 1/4" to 3/8" smaller 5 shot groups @100 yards, when compared to factory brass.
The Win or Rem factory brass is taken from a bulk bag of 100 pcs. Case mouth is made round by bumping with an expander. Necks are not expanded or sized, if they hold a bullet. Primed, powdered & bullets seated.
The same lot of brass is used to compare the process using a 243Win Rem 40XB rifle.
I'm saying with the average reloader there is no significant difference. No advantage or disadvantage.

I agree, using standard reloading methods.
 
I'm saying with the average reloader there is no significant difference. No advantage or disadvantage.

In fairness, “the average reloader” isn’t making very good ammunition and is happy as a clam with it because they’re also not asking very much of it: so their need and their ability to produce - even their motivation to produce - highly consistent ammunition is low. “The average reloader” is slapping together ammunition based on a process they learned somewhere between Uncle Jack, the instructions which come with the die set, or the front of the reloading manual - certainly producing functional and reliable ammo, but not precise. They’re then shooting that ammo at 100yrds or less.

So talking about differentiation for “the average reloader” is rather moot. Much like adding horsepower to the typical grocery-getter, it just doesn’t matter for the average Joe driving it… but for anyone pursuing an application where horsepower matters - then horsepower matters. I typically can see sufficient difference in velocity to change my POI at 1,000yrds.
 
With the most common form of brass preparation being full length sizing, I can see no benefit in fire forming. The couple of thousandths between new and shoulder bumped brass seems totally insignificant.

Then don’t do it.

I have seen some cases (pun intended) where it didn’t make any difference and others where the variables stacked up so it made “all the difference” in getting a rifle to shoot.

If it ain’t broke, don’t fix your routine but if you just can’t figure one out some time, give it a try, it just might be the solution.
 
Arbitrarily, let’s say virgin brass is sized to minimum specification, which is 15. Let’s say our chamber is actually 20. We fireform to move the 15 to 20, and then we set our sizing die to 18 to ensure we’ll not have feeding issues in the future. Obviously, there is a difference in internal volume for brass which is 15 and that which is 18. But when we have 18 upon every firing because we bump the same once brass is brought up from its original, undersized state, we have consistency.

I agree that at least theoretically that’s spot on. In my experience though it’s not. Maybe for precision shooting it would make a difference but everything I have fireformed if I load it just like a regular load then it works just like a regular load. It doesn’t matter if you start at 18 or 15 or 20 for that matter. Cartridge brass is so malleable that it blows out to chamber size and shape and for everything that I have been able to figure out with both .256 winmag and 7-30 waters after the initial forming while they are still ugly as sin you can just load them like they are already fireformed and shoot them with no discernible difference in ballistics. My assumption is that the initial pressure spike happens while everything is still contained inside of the gun so before the bullet leaves the barrel everything becomes the same. Internal ballistics don’t change enough to affect external ballistics, and we know that every shot the brass ends up at the same point and has to be ever so slightly bumped so the case forming must happen no matter the initial size whether it be 15, 18, 20, or whatever arbitrary number you throw at it. If the charge fits, it works.


Please don’t take that to mean that anybody can just drop max loads into a virgin reformed case and let-are-rip. Gotta be sensible and stay within book limits and preferably on the low end of book limits. Don’t blow yourself up. And again, for extreme accuracy you can probably tell a difference, but for what I have done I can’t tell any difference at all. I will have more experience soon when I get to use my newest contender barrels which will both be using reformed brass.
 
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I suppose it might make sense for me to share how I manage the offset of fireforming - within the definition of simply improving chamber fit as well as of case forming, such as the examples @Walkalong shared above.

For virgin brass which is already formed to the appropriate chamber, I may still use that ammo in competition, but I’ll redo my load work up for the next firing. Relatively low impact, however, because I only need 24-30 rounds to do so. I check my nodes again, often the boundaries for which will move a tenth of a grain, or two - not sure I ever recall moving 3 tenths, and may become wider or more narrow.

For case forming, such as blowing BR brass out to Dasher, or 243 or 7-08 to AI, I would also have a known work up for the unformed cases, then rework once the cases were formed. I wasn’t above shooting a club level match with false shoulders and fireforming loads, however, I’ve committed to hydroforming Dasher brass to reduce my dependency upon primers for case forming, and reduce the offset between my forming loads and my expected final loads.

In either paradigm, managing fireforming as a part of life isn’t a burdensome task.
 
So were fire forming for the die not the chamber????
I’m not, I think it’s understood within the community that we form to the chamber dimensions.
I have shot fresh 6 br Norma cases with a full recipe enjoying excellent results but I wasn’t load developing
 
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however, I’ve committed to hydroforming Dasher brass to reduce my dependency upon primers for case forming,

This may lead us down a rabbit hole, but I have to ask how you are hydroforming cases to your chamber dimensions. I can imagine a couple different ways but they would either be prohibitively expensive or crude and messy. Please explain your process.
 
This may lead us down a rabbit hole, but I have to ask how you are hydroforming cases to your chamber dimensions. I can imagine a couple different ways but they would either be prohibitively expensive or crude and messy. Please explain your process.

Whidden hydroforming die, set to ~3thou over a length which will close into chamber, then sizing back in an FL die back to 2thou bump. Adds a bit sharper shoulder than conventional hydroforming principle, which would normally be set to blow out just large enough to still close.

It’s messy. Such is the nature of the process.

F9E868D7-E9AF-438C-ABD4-904876B17189.jpeg
 
For case forming, such as blowing BR brass out to Dasher, or 243 or 7-08 to AI, I would also have a known work up for the unformed cases, then rework once the cases were formed.

This is exactly what I did. Developed a fire forming load. It’s lower in velocity and not optimal for a serious match duty, but it is accurate enough to allow me to put my components to better use than just sitting at the bench burning 200 rounds of bullets, powder and primers for the singular purpose of forming brass.

And, as a bonus, you have the handy excuse of, “well, I was forming brass” to explain that random 8 ;)
 
While reading the front matter of many a reloading manual, and discussed commonly on the internet and YouTube video, the glory of fire forming is presented. As with many ideas there is, this great idea presented, which would seemingly apply unilaterally but doesn't. There are applications where I believe it provides large benefits, but they are not detailed as they should be.
1. If you neck size. Old military rifles and varmint shooters alike that practice the art of neck sizing.
2. If your going through the process of having a custom die made. Also includes neck sizing.
3. If your converting brass in a different chamber. Ackley is the most known version of this processes.

With the most common form of brass preparation being full length sizing, I can see no benefit in fire forming. The couple of thousandths between new and shoulder bumped brass seems totally insignificant. Am I missing something???
Well, first off, you asked the question, “is it still relevant,” then name three scenarios where it is. So, you answered your own question in the op. Second, while everyone concentrated on rifle and accuracy, all y’all forgot about rarity of certain pistol and revolver ammunition. Plain old 9mm Luger fresh picked off the range turf is 1st-stage fire formed 9mm Makarov brass. To make Mak from Luger it’s gotta be fired to open up the base. By the same token, the best way to open up .45AR or ACP for loading .455 Webley in a cut Webley revolver is to shoot it in a .45ACP revolver or automatic, again to open it up for a larger bullet. Now, both those fit your No.3 but like I said, those three scenarios you pointed out answer the original question. But they don’t strictly apply to rifle as seems to have been assumed.
In my experience, there’s no such thing as “average reloaders “. There’s folks who learn and folks who just follow directions and aren’t any of them average. You’d have to assume people are automatons for that average thing to work out. I don’t believe any such thing.
 
I suppose it might make sense for me to share how I manage the offset of fireforming - within the definition of simply improving chamber fit as well as of case forming, such as the examples @Walkalong shared above.
Yes, I think AJ has a different definition of fire forming than I do. Fire forming to me is changing the case to another caliber, not just forming caliber A brass to caliber A chamber. That's just differences in sizing your cases.
 
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