Fire Forming

[sammass]

OK, I'm a reloading newbie and some processes just don't seem logical to me. Ergo... lots of questions. :-)

The basic question is how does one fire form brass into a larger size? Saw this advert:

".284 Win brass (Winchester-Western Super headstamp) fireformed to 7.5x55 Swiss and Boxer primed, ready to reload..."

Looking at the dimensional drawings of both cartridges - Hornady 7th, the numbers are close but off. How does one expand the rim of the cartridge 0.025? I'm envisioning a .284 pill rattling down the 30 cal barrel. Too many questions rattling around to even post them all.

Overall, would appreciate any suggestions for reading material.

If one does use a smaller cartridge, now fire formed larger with the head stamp intact, how do you mark the cartridge so someone like myself doesn't now shove a 30 cal bullet down a 284 tube?

Thanks for the lesson.

[thenodnarb]

It was probably sized with a 7.5 swiss sizer die to open the mouth, then a "fireforming" load was fired in the Swiss which effectively makes the cartridge take the shape of the chamber, which it might not have been able to do perfectly with just a sizer die.

Edit to add:
with my .303 enfield, I bought some PPU brass to load. Since they hadn't been fired in any chamber yet, and since enfields have a LOT of head space, I chose to fireform the cases. I did this by loading a projectile with a pretty mild powder charge. However, since the enfield is rimmed, I slipped an oring around the case so that the rim would be pushed hard against bolt face when chambered. This forced the case to expand forward mostly in the shoulder area and not in the head area of the case. Now, I neck size them only, and they headspace off the shoulder instead of the rim, giving me hopefully 10-15 reloads per case instead of 3 which is typical from .303

If you are really chasing accuracy, you will fireform you brass to your chamber before working up a load. Obviously you need to neck size as well.

If one does use a smaller cartridge, now fire formed larger with the head stamp intact, how do you mark the cartridge so someone like myself doesn't now shove a 30 cal bullet down a 284 tube?

Thanks for the lesson.

The cartridge with the 30 cal bullet wouldn't even chamber in the other firearm with the .284 bore. The bolt wont close. You won't be able to pull the trigger. The problem comes from people shooting things like .311 projectiles down a .308 bore. They will still chamber, but pressure will increase big time, and possibly ka-boom.

[OpenSightsOnly]

Its doable to FL size 284 Win brass using 7.5 Swiss FL die. Folks do that since the casehead dimensions are close and 284 Win brass is very good. It would be a lot easier if your 7.5 Swiss FL die is already adjusted for your K31 chamber.

Considering PPU and Norma have 7.5 Swiss brass, you might as well just buy those.

Light loads (some folks try to get GP11 velocity of of their reloads, I don't since my targets are only 200 yards. If I want GP11 velocity, I'll use GP11) and annealing should extend brass life.

[sammass]

Fellas,

Thank you for the explanations. I haven't adjusted to +/- leeway when the drawings are exact.

I believe probably just purchasing the brass in correct size is the easiest solution. Appreciate your help. :-)

[ducky_0811]

You will find that PPU brass is very good. I have been able to get sub moa groups with careful hand loading and a swiss products scope mount. If this is for a k31 I would HIGHLY recommend the redding dies as they are set to the k31's wider chamber at the shoulder. These will not work the brass as much and extend case life. Hornady also makes a k31 specific die set but I have never used them.

[OpenSightsOnly]

RCBS, Lee, Redding, and Hornady all work.

The K31 specific dies are a marketing ploy - just stock up on brass.

Annealing and moderate loads will extend bore and brass life.

[Whiterabbit]

The basic question is how does one fire form brass into a larger size?

2 ways. If you can seat a bullet in the case and fire it from the gun safely, then load it and fire like normal, assuming the case is close. Or, load a reduced load and fire. It works just fine. A good example of this is firing a std case in an ackley improved chamber to fireform to the new chamber.

Other way if you cannot seat a bullet (for whatever reason) is to put a pinch of pistol powder at the bottom of the case, then fill to the top with cornmeal. Nicely packed in there. Fire. Reload as per normal. If you get a bad chamber casting, put two pinches of pistol powder in next time.

(I neck up 378 bee to .510" with 10-20 grains of bluedot. I'd use much less if it were a smaller case)

[waveslayer]

There's a great video from a guy in England on how to use the Cream of Wheat method

[Whiterabbit]

did he fireform pointing the barrel straight up, or pointing downrange?

Just curious.

[ducky_0811]

I wouldn't say the k31 specific dies are a marketing ploy. The case shoulders get worked an extra .020 in rcbs dies. I know, bc I have both rcbs and redding. Annealing will in fact extend case life, but how much time per case do you want to spend? How much is your annealing set up going to cost you? Stocking up on an extra bag of PU brass will cost more than the extra money spent on the redding dies.
Light loads will surely do the same thing, for me, I like shooting out to 500 yards so I want a full power load. Pick a set of dies and reload to your needs. Different strokes for different folks. Not saying anyone is wrong, just know what is out there and use equipment that will suit you the best.

[OpenSightsOnly]

The K31 chamber is "generous" if compared to a 1911 long rifle chamber since the K31 chamber is designed for feeding reliability.

Whenever a brass is sized or cold formed, the neck is the area is getting worked as opposed to the shoulder. Annealing mitigates the neck splits and also brings about a consistent neck tension.

I agree that the capital outlay for annealing equipment can be cost prohibitive. So, if that aint anybody's cup of tea, then it would be best to stock up on brass.

By the way, since the shoulder area of the chamber of a 1911 long rifle is tighter, compared to a K31, the dimensions near/around the case head is somewhat generous. I noticed that since a once fired GP11 brass has a distinctive ring around the case head. That is designed to facilitate extraction. I'm bringing that up as comparison brass is getting worked by the dimensions of the chamber as opposed to the die. Just sharing an observation

[Whiterabbit]

if you are not concerned about uniformity, you can do it with a propane torch. that's a $2 capital outlay.

[mark501w]

Isn't .284 a rebated case?

[Mr Blu]

The basic question is how does one fire form brass into a larger size?

Acquire NEW brass/projectiles/powder, load to the minimum safe specs for your rifle in a loading manual, such as the Lyman 49th Edition, then fire them.

It's a little costly, due to using components to do nothing more than prep, but you will get fire formed brass.


PS -- I say new brass because you don't know how many times "once fired" brass was actually fired or with what load. Also, you will essentially be using up 2 uses of the brass, for the "price" of 1. That 1 being your first actual load to test. Meaning you will get less life out of your brass. I have heard of people using brass up to 12 times, but that's pushing safety boundaries. In my opinion.

(I'm not saying once fired is bad. Just being extra cautious.)

As an expansion on what I'm talking about, with regards to uses, "the hotter the load, the greater the expansion of the brass, shortening the time between full resizing of the brass, the fewer uses you will get due to increased wear". You will also get fractures sooner, as the brass wears out quicker. It's better to just choose a maximum number of uses before tossing the batch. That way, you will have less of a chance of loading brass that's reached the end of its service life.



If I'm wrong, I'm wrong. But that scenario is what I have come to understand, from many talks with more experienced loaders.

[LynnJr]

WhiteRabbit
You can point the gun downrange when using Cream of Wheat.
I use 15 grains of Unique then completely fill the case with Cream of Wheat. I then tap on the side of the case with the same spoon I used to fill the case until the COW has settled to the base of the neck.
I then use a 1/4 sheet of toilet tissue tamped in place with a small screwdriver to hold the COW from spilling out.

If your going to a larger diameter neck it is advisable to use a false shoulder. The false shoulder holds the case firmly against the bolts face preventing case stretch in the web.