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In an ongoing quest to learn more about converting 9.3 X 74R brass to 3" .410 brass I am wanting some info about annealing the top third of the case. It seems to be pretty much a given that the top third of the case should be annealed before allowing fire forming to expand the neck to .410 chamber dims. After reading up on doing it, and seeing everything used from a $1300 electric induction annealer to a handheld propane torch, I'm left with a question about the process. I see conflicting methods concerning the cooling of the brass after the heating. Some dunk them individually, and immediately, in water. Benchrest shooters, who use the expensive annealer I mentioned above, seem to let the case cool on it's own (in the videos I watched).

I've always been told that to properly anneal an action, or any other piece of steel, it should cool as slowly as possible. Some used to even pack them in lime to extend the cooling down period. Is brass different? If the idea is to relieve internal stresses in the case shoulder and neck, and result in maximum ductility, wouldn't a slower cool down be better than a quick dunk in water?

Stan,
I think this is the color you may want to try.
Personally, I don’t think the temp range is highly critical unless you just go way overboard.

Ken

I have successfully fireformed some cases now. The last load used in the process was 15 grs. H110, two 7/16" card wads punched out of old shell box cardboard, 450 grs. no. 9 shot, and a 7/16" overshot card wad. This load finished fireforming the cases well. I doubt the lower 1" of the case will ever enlarge to full chamber diameter, but the rest of the case out to the mouth is nice and straight with no splits. (Yes, that 450 grs. of no. 9 shot is over one ounce, but that was without nitro and cushion wads).

Now, I move to the load development stage. Goal is to develop an efficient non-tox load of no. 6 Nice Shot for woodies ........ all the case can hold. I'm hoping for a bit over 3/4 oz. at a velocity somewhere between 1150 and 1200 fps.

Stan,
You have so many people giving advice it must seem very complicated. This is your project, you should use the advice you are comfortable with and fits the equipment and components you have; if this is someone else's advice, my feelings won't be hurt. Different powders will work, you just have to adjust the charge weight required for the particular case being formed. I suggest you load a couple cases with 4 or 5 grains of powder and the grits, fire them and adjust the charge until you are satisfied or decide it is safer to anneal and fireform more than once rather than add more powder after noticing pressure signs.
With regard to reduced loads causing detonations, the reports were with slow burning rate powders, the classic case was with 4831 in the 270 Win. I have a 5.6X61R vom Hofe Super Express and did pretty extensive research trying to find a firsthand account of detonations (the .227" bullets I had required less velocity than the load data I had in order to shoot acceptable groups) but could not verify they actually occurred. I switched to a medium rather than slow burning powder, anyway. You don't need to worry about reduced charges of fast burning powders.
Mike

This morning I made a huge step forward in this process. I put about 1/2", maybe a bit less, water in a cake pan and set five cases in it, base down of course. I then heated each until the neck/shoulder area was briefly reddish in color, but played the torch flame down the cases all around until they were annealed to the water line, then tipped them over. Primed and loaded each with 4 gr. Bullseye, a small toilet paper wad, then grits, finished off with a 2mm wax plug. Firing gave a great deal of expansion, but not 100%. Re-annealed same way, and reloaded same way. Next firing gave 96+% full fire-forming.

They're good enough now for a medium load of powder and shot. No signs of splitting anywhere. I know it's better to be safe than sorry, but the 4 gr. Bullseye seems so light that I wonder what the results would be on the first firing if I upped it to 6 gr.

As Mike told me a couple days ago, this has turned out to be a two or three step/firing process. I had previously thought it could be accomplished with one firing. If I had known the effort required to do this with 48 cases I may not have ever taken the plunge. Probably better that I didn't know up front. Anyway, I'll load up the five cases with a lighter than normal hunting load and see if we complete the "smoothing out" of the case walls. If I get the time to mess with them tomorrow morning I may have some pics. I must say, it is looking promising, if not economical (in terms of time and effort).

The goal from the outset was to have .410 cases that had more case capacity than anything you could buy. I am cautiously optimistic that we will, indeed. Oh, BTW, I am using a Yildiz double barrel to do the fire-forming.

When I was into shooting the obscure .41 Swiss out of the old Veterlli rifles I made all my rounds from .348 Winchester. It’s not the quench that’s so important as how hot you get your brass. Heat just at the neck and shoulders enough to get a color change, blueish. You can dunk them or let them air cool. I assume you won’t be full length resizing.

Used to do lots of NRA hi-power and later F-class shooting. I just always did the heat with torch and dunk method. I do seem to recall a reasonably priced anealing machine being available a few years ago, much less than the $1300 you mentioned. I'll see if I can find it again.

Stan,
To get the results you are looking for, you are going to have to anneal the cases almost to the head. Note that the "almost" is very important, you don't want to soften the case head. A cousin of mine is making cases (65mm long) for a double rifle, from 9.3x74R. At first, he tried some 7x65R cases (I had previously recommended these on this board for similar rifles), but after trying every procedure we knew, he was unable to expand the 7mm necks to the necessary diameter without almost 100% of the necks splitting. The 9.3 necks didn't exhibit unacceptable losses. He did, however, have to fireform them several(3or4) times, progressively annealing each time, before the bodies completely expanded. After the initial fireforming he did the rest while testing loads, so it was not an unacceptably long process. The final result is nice looking cases. The annealing you need to do is for an entirely different purpose than the ones shown above.
Mike

Turn the sound off and this video is so relaxing to watch!!

I've never reformed brass cases, but I'm a metals nerd, and, from what I've read, when expanding a bottlenecked rifle case into a straight-walled case of larger bore diameter, annealing is necessary to prevent the cartridge from cracking or splitting at the case mouth. Because the simple act of bottlenecking what was originally a straight-walled tube during the case--forming process at the factory, has already work-hardened the brass somewhat. De-bottlenecking it means stretching already-stressed metal. It might not like it without being stress-relieved first.

Nothing to do with the chamber pressures.

I of course invite correction from those who've done it. I'm here to learn.

I seem to recall reading many years ago that a way to do this by hand, and keep the case head from annealing is to put water in a large rectangular cooking sheet with raised edges, deep enough that the case can be stood up with the head in the water, then heat with a torch going round and round. Then, when the case is the right color you just tip it over into the pan of water.

I was afraid that the quick cool off by the water would defeat the reason for annealing, to a degree. I'm certain this is the case with iron, but with brass, evidently not.

Thanks for the helpful replies.

Stan,
If you hold the cases in your fingers, by the head, and turn(twirl) them in the flame of a torch it is not possible to hold them until the heads are hot enough to anneal. Steel and brass work differently when annealing. Somone mentioned annealing cases causes them to buckle at the shoulder. This is a valid consideration, especially if the necks and shoulders are overheated and they are being expanded with the sizing die's expanding button. If overheated, but fireformed, buckling will not occur during the initial expansion. In severe cases of overheating and fireforming buckling may still occur when the expander enters the neck during the sizing for loading. This can be reduced by lubricating the inside of the neck and/or using a tapered expander. Generally, this sizing and the subsequent expansion when the cartridges are fired causes enough work hardening that buckling is not likely to occur afterward.
Mike

If you are worried about consistency, and have a thermometer, you can do the old stove pot, filled with sand, on a camp stove or hot plate. You can control the temp., depth, and time if you want? I'd hold it in my fingers, and I would drop it in water, again for consistency. Whatever you do to the case, will stop on the spot.

I'd lean towards lesser annealing, maybe like Ken's picture? With good brass spring back, you may never have to figure out how to resize the long case. I'm assuming overshot card, maybe needing a relatively heavy crimp, so just a bit of the mouth may appreciate regular annealing. Only thoughts, best of luck with it.

When expanding .30-40 Krag cases to .38 caliber, found the shoulder would collapse if annealed beforehand.
Expand neck (Good lube in required) first, then anneal, then size cartridge.
Chuck

Going from 9,7 mm to .410 (10.414mm) is an expansion which isn't that significant considering that 9,7mm is the round's diameter and not the case's mouth diameter. A buddy and I fireformed over 200 5.56mm rounds to 7mm without annealing. We shot the 7mm TCU round in competition. I don't recall any problems. Gil

https://www.scheels.com/p/annealeez-gen-3-brass-annealing-machine/42100030405.html


$275



This is the one everybody was using.

Why not cut the parent cartridge to length, anneal as required and expand the case with the appropriate diameter mandrel? Little or no fire forming required.

Scratch the trimming idea. The parent case is just shy of 3”. I still think the neck can be expanded to sufficiently…..I may try that in a few days.

Thanks again, my friend. I do intend to expand the necks by fire forming, so shouldn't have any problem with buckling as the forces involved will be acting in different directions than when using an expander button in a die. I had watched a video showing how someone used a torch and did it as you say, by hand. That is the method I will use. I may do a few this morning, load them up, and try the procedure. To be continued ........

I have to form brass for my .33WCF 1886 Winchester from .45-70 brass using a .40-60 sizing die as an intermediate stage.

I anneal before each step, holding the case rims in my bare fingers while rotating the neck in a gas flame.

The need to let go of the rim when it starts to become uncomfortable, dropping the case into a water bucket, avoids any risk of over heating and softening of the case head.

It may not be very precise, but the annealing colours usually extend to just below the case shoulder.

Stan,
I wonder why you are using black powder to fireform the cases? We knew it would require annealing and fireforming more than once (3 or4) to obtain straight walls, and the extra cleaning operations(washing) of black powder residue will add additional steps in the process. I recommend using a fast-burning smokeless pistol or shotgun powder with a 1/4 sheet of toilet paper tamped over it and the case filled with grits, worn out polishing media, corn meal, or cream of wheat, and another 1/4 sheet of toilet paper, Styrofoam (coffee cup), or wax to stop it off. The black powder not only leaves a lot of residues, but it takes up a lot of room needed for filler.
Mike

I have fireformed and necked down more cases than I can remember for wildcats and have used the same method for decades. I won't go into necking down, since it is much more complex. To expand anything, I set the cases in a flat pan of water to a point above the head of the case, take a propane torch and go up and down the rows, heating the exposed case until it is red, then tipping the case over into the water. Then I prime the case, use 3 or 4 gr of Bullseye, fill the case with cream of wheat and stick the neck into a bar of ivory soap and snap the plug off. Ivory is cheap and pure(remember?). Fire it off and you have a case, which is probably hard again at that point.

One thing I found when trying to make Paradox cases for an odd German Cape gun I had. Brass is very unforgiving. I started with 20 ga brass shells cut to length. annealed the mouth and loaded round ball rounds with a Paradox style crimp over the ball. Not excessive but just enough to hold it in place. The crimp was easy in the freshly annealed case. After one firing, I could not crimp the case without a new annealing. I gave up on that and simply glued the ball inside the case like an overpowder wadin a brass shotshell.

Parabola,
Black powder Silhouette shooters created enough demand that Starline (and maybe others) started making 40-65 cases again. Unless you already have a significant quantity of 45-70 cases, you should be able to save at least one step in your 33 Winchester forming process. Of course, if you don't need to buy cases, the saving in time and trouble may not be worth the cost of 40-65 cases. It may be worth a look.
Mike

Stan,

I have been watching this thread with interest as I was given some 9.3x74R brass with a view to reloading it as 3” .410.

If you are concerned about pressure spikes in fire-forming the answer may be to find an old single shot .410, as long as it has a clean chamber, and use that for the fire-forming.

Most of those single shots have relatively massive chamber walls and the ideal would something like a .410 Baikal single which is almost indestructible.

Stan,
Now that you know 4 grains of bullseye is too small a load, I think you can increase the second fireforming load to 6 or more grains. Craig's suggestion to load a starting load of shot after the initial forming is worth a try. The case walls not being straight would not prevent using shot as it might prevent seating a bullet. You might have to use a toilet paper wad as an overshot load, though. This could reduce the number of loads needed to blow the cases out.
Mike

Pressure Testing brass shotshells: I discussed this with the owner of Big Bore Ballistics. He has to use a special drill technique near the head of the shell to drill a hole into the brass in order to drive a piston in his pressure testing apparatus. Not so with plastic hulls. Tom Armbrust refers TSS testing to him. Precision won't test brass shells. Just a heads up if you should want to test once you establish satisfactory velocity. Gil

Mike, I appreciate your, and other's, advice here. The catch is taking that advice and figuring out how to apply it. I may not be doing something quite the way the poster does it, and makes it work for them. When I annealed five cases by turning them with my thumb and finger, in the flame, I tried as hard as I could to do the top third of the case. By the time I got what I thought was an acceptable color change the head of the case would begin heating up to the point that I'd have to quickly drop in in a loading block to keep from being burned. This morning I cleaned the 5 cases of the black powder residue in my ultrasonic cleaner, annealed them again, reprimed them, and loaded them with 8 grs. of Longshot, a 1/4 sheet of toilet paper wad, filled the case almost to the top with grits, then used a plug from a styrofoam cup on top. This was the result.



As all can see the only thing that expanded was the neck, even though I attempted to anneal a good ways below that. It's no fault of anyone's. It's just incomplete results. I'm learning, and I'm making progress. I'm reading all I can and, as you say, figuring it out for myself with the gracious help of yourself and others. Tomorrow morning I will use the cake pan and water method on five cases, heat until reddish, and quench. Then I will load only one with the Bullseye load AGS suggested and see what happens. Tomorrow I will seal the mouth of the case with a plug of 2mm wax I had ordered and that came today.

I'm putting all this on here in the hope that someday someone else can skip the things I have tried that gave incomplete, or inconsistent, results and go straight to a successful procedure. Again, and I really mean this, thanks to all who have taken of their valuable time to offer suggestions and help. What fun!!!

To be continued ........

Stan,
When annealing by hand I put a coffee can with water directly under the torch, which is standing on the edge of a bench/table, so all I have to do is open my fingers and the case falls into the water. Off and on I dip my fingers into the water if I feel too much heat. It is not really necessary to heat until the case turns red, in fact with a necked case, over heating is what causes the shoulders to buckle. Some people fireform using a bullet instead of filler, but with the filler, you can't create excess pressure and you save bullets. If you have a single shot 410 with no choke, you could take Parabola's advice but load cast bullets. My cousin's final fireforming for his double rifle was with cast bullets while working up acceptable loads. I don't have anything against using a machine to help in the process. You may find an easy to build one on You Tube.
Mike

Stan,
Great news that you figured out the key to fire forming the cases. I knew you could do it when I saw you wouldn't give up. I'm sure now that you will also find a shot load that will satisfy you as well.
Mike

In rifles with much high pressures, I moved years ago to fire forming with a starting load for whatever cartridge it is. I would consider experimenting on just two of those cases. Maybe, anneal again, put a 410 starting powder charge in, probably have to hand seat a fiber, maybe have to trim it, probably a little less shot, and possibly qlue in as mentioned earlier an overshot card. Build a little safe back pressure, and it'll blow out. Pattern it just for grins?

Your brass may be pretty hard, just back of the point it didn't expand, or it may have acted like there was a bit of an air gap. Maybe it doesn't need annealing. I wouldn't worry about cleaning the annealing colors, until you have it humming along like you want it, and even then it might look neater, lol. Anyway, hang in there, it'll work.

The issue would be if the single-shot's chamber was oversize in comparison to the chambers Stan intends to shoot the ammo in. If smaller, no problem. This is based on my experience with .410s and brass hulls. Gil

One thing you can try with plastic wads to expand the gas seal is to mash and twist the seal against a round metal object. I do this with TPS wads in turkey loads shooting TSS. I've also wrapped Teflon plumbers tape around seal, tucking overage into cup. Another method is to peel apart an OSC to about half thickness or less and place it directly on the powder and seat the wad on top. With fiber wads, no need to split. With plastic wads I want the powder to push the osc into the bottom of the gas seal's dome shape. I store extra shells mouth up and don't leave them in the truck in which road vibration can contribute to powder migration if shell isn't upright, head down. My powders are fine ball powder in .410 and more prone to migrate than flake. I've not had a blooper but others have with other gauges, ball powder and certain plastic wads from BP in plastic hulls. Clear plastic wads by FIocchi allows observation of possible migration past the seal in 12 ga. Gil