powder for fireforming

[lylejb]

A future project I'm likely to undertake will be fireforming some brass for a 308 norma mag. The Brass I'm going to start with is 300 win mag.

What would be the best route for fire forming? A small, fast powder charge like 10-12gr unique.

Or something like a starting load from the loading manual, like 58gr of 4064?
Kind of reluctant to burn that much powder just to form cases.

The fireforming loads will be just that. I don't care about velocity, accuracy, ect. These are just to get the cases into shape.

Anybody tried trailboss for this?

Any tips on fireforming?

Thanks.

[Jim]

10 to 12 gr. of Unique is a lot cheaper than 58 gr. of 4064. I use about 6 gr. of Bullseye under a hard RB for my fire forming.

[SCHUETZENBOOMER]

Lyle,

Get P.O. ACKLEY'S books! Read about fireforming BEFORE you do it. It is my experience that VERY FEW people have any experience with fireforming and are repeating what they have heard or read somewhere else. I was hoping to beat others to this post so as not to step on any toes. This IS NOT my intent.

I have fireformed hundreds, if not a thousand, cases. My advice (FWIW) is to anneal the affected area first(read up on it if you have not done it), load a HEAVY boolit, with SLOW powder.

One last suggestion is to make a gage to measure the location of the fireformed shoulder relative to the cartridge base. Have a machinist friend make a 3/4" round x 3/4" long bushing with a hole thru it a few thou over neck dia. (closest drill size is fine). Chamfer one end on the ID. Leave the other end sharp or make sure you stamp that end "up". In use, slide the chamfered I.D. end of the bushing over the case neck of a firefomed cartridge. Measure the overall length of the cartridge (including the bushing seated onto the shoulder) with your calipers. THIS IS NOT A HEADSPACE MEASUREMENT, ONLY A RELATIVE MEASUREMENT TO GAGE COMPLETE FIREFORMING. What you are looking for are fireformed cases that are .005" to .060" short of the "average". Ackley explains this far better than I. I can attest to it happening.....the case will look perfect but be .060 short at the shoulder!

[Bullshop]

I am not really sure why you will need to fire form. The 300 win is longer than the 308 Norma. The Norma case has the shoulder farther back than the Win.
As I see it all that is needed is to run the 300 Win brass full length into the 308 Norma die then trim to length.
I am not looking and body diameter differences but I don't think there is much difference there. This should be all mechanical forming, no shooting needed. If there will be a slight increase in diameter at the shoulder it cant be much in any.
I have a feeling I am missing something.
BIC/BS

[GabbyM]

I no nothing of belted magnums. With my 243 A.I. My preferred method is to simply use my cast boolit load. All my brass is used 243 WIN from previously worn out barrels. So after it's run through a body die it's a snug fit so not much chance of a short form as mentioned above. If I had new brass that had some play in it after cambering I'd load a cast bullet at a length to jam the case back against the bolt face and line up the case to the bore line with bullet snugly located in the bore. This must be tight enough to prevent the firing pin from driving the case forward at primer strike. So you need the front band into the rifling a bit.

If your cases are loose in the chamber at their base you can wrap the case with a narrow strip of scotch tape to better align the case head in the center of chamber. Preventing that bulged on one side ugliness.

Depending upon how tight your belted rim head space is you may not have any issue with driving the case forwards with the firing pin. But in the end you want the belted rounds head spacing off the shoulder.

[Bullshop]

If he is forming 308 Norma from 300 Win mag he can head space off the shoulder from the very firs shot. The 300 Win has the shoulder farther forward than the Norma so all he need to do is partial size the 300 Win cases in the Norma die until they are a snug fit on closing the bolt on them. That is of course after trimming to correct length.
BIC/BS

[SCHUETZENBOOMER]

Bullshop,

You are entirely correct. I completely missed them being belted.

[Bullshop]

The belt in this case has little to do with it. He can treat it as if it were belt-less and head-space off the shoulder from the start.
If he was trying to do the opposite of what he is doing, that is if he were trying to push the shoulder forward instead of back then for the first shot he would have to HS off the belt.
The only safe way to do the same (move shoulder forward) with a rimless case is to neck the case to a larger caliber than what your making like say if your making a 35 Brown Whelen from a 35 Whelen you would neck up to say 375 then partial size until the case is a tight fit for the chamber. That creates a zero HS condition that only allows the case to stretch outward and not forward. Forward stretch if sufficient causes seperation. Look in the Ackley book Q&A section and see what he had to say about it after a gun was blown up using the bullet to HS off of.
BIC/BS

[mtnman31]

Interesting thread with perfect timing. I am getting ready to fireform some 8mm Lebel cases to use in the 41 Swiss. This is my first foray into fireforming for a case caliber conversion. The 8mm Lebel cases are virgin. Being that these are rimmed cases headspacing shouldn't be an issue. Should I trim a little length off them first or just go at it? Right now, I have Unique, Win 296, Power Pistol and 4895 on hand. Any pointers or guidance are greatly appreciated.

[john from md]

To make your brass last the longest, do the following.

1. Full length resize and trim
2. Anneal the neck
3. Load with 5 grains of Red Dot and fill with cream of wheat till full. Seal with a drop of elmers glue all.
4. Keep fired cases separate for each rifle. By doing this, you only need to neck size and the brass will live much longer.

I usually get seven to ten reloadings before I have to anneal the cases again.

I have been shooting wildcats and making brass for forty years. Considering the work involved in making some calibers, I want my brass to last.

Regards,

John

[John Boy]

My advice (FWIW) is to anneal the affected area first(read up on it if you have not done it), load a HEAVY boolit, with SLOW powder.
+1 and use ... Black Powder!

[blaser.306]

Won't black powder deteriorate the brass casings the same as it does for BPCR ?
Thus shortening the cartriges life !

[405]

Bullshop,

You are entirely correct. I completely missed them being belted.

Regardless, SBOOMER, your post is still right on the money. I think it is fairly important to use those techniques for any bottleneck fireforming no matter the headspace design of the case. No harm will come of it and case life will likely be increased if minimal case stretching happens just forward of the head... particularly with the headspace-on-shoulder cases.

The part about the parent-to-improved fireforming of bottleneck cartridges is missed, ignored or not understood by many who do it... but still it is a real phenomenon. I've tried to explain it several times but get reactions like I've got three eyeballs in my forehead :) I think the case/neck shortening after fireforming to an "improved" version is a result of the case brass "borrowing" material from both the neck and upper body of the case during the forming expansion to fill the larger upper body and shoulder.

[ebg3]

+1 in not using bullets in the fireforming process. A small charge of a pistol powder and the case filled with cream of wheat or something similar will do the trick. I once fireformed some .264 STW brass with just a charge of VV330 pistol powder. I would just point the gun up and fire. Problem was, I had to use too much powder, without the case filler, and I coated the barrel with hard powder fouling. It was a nightmare to clean.
EG

[SCHUETZENBOOMER]

My experience with fast powders and light bullets(boolits) is high case loss from splits and partial case separation somewhere mid-case. It may not even be evident in looking at the cases. Make a small sharp hook scriber and feel down inside of the case. If you suspect an anomoly....section the case on a grinder(belt sander works nice). I think you may be surprised at what you see. I will post a pic tonite of some samples I have used for visual training.

405,

Just so we are on the same page. I do not mean shortening of the neck(and you are correct, it is material flow that has to come from somewhere), I mean a perfectly formed, sharp, improved shoulder that is up to .060" short of the intended location. I have had this happen many times. Ackley warn's of this. Quite by accident, I was able to duplicate this fairly often using some pulled surplus flake powder from old 8x57 186gr fmj's (in bandoliers from Century 10 years ago). This is why i suggested the gage to verify shoulder location.

Like I said, I have extensive fireforming experience with the Ackley design. Over the last 20 years I have developed a full compliment of wildcats all based on the Ackley concept. I see single digit SD on several of my "GP" cartridges . Ackley was on to something with his design and he knew it. Here is a pic of my "bullet board". Wish I had publicly pushed the .330GP and .375GP prior to these two calibers storming the scene a few years back. These were two huge voids in the commercial realm.

[BruceB]

Bullshop is correct.

In this particular operation, making .308 Norma from .300 Winchester, there is no need whatever for fire-forming. Trim to appropriate length, and then begin sizing progressively in the .308 Norma sizer until the bolt will barely close. Job done. By sizing down until the bolt just closes, it doesn't really matter WHAT surface is being used for headspacing. I prefer to use the shoulder, as suggested, but the belt is at least a stopgap. Belt tolerances on cases are too loose for my tastes, and any belted mags in my rack get ammo headspaced on the shoulder.

It's a LOT less work to just neck down .338 brass or neck up 7mm Remington Magnums. However, I can appreciate that if .300 Winchester is what you have and want to use, then it makes sense to put the stuff to good use. I once fire-formed a bunch of .264 Mag brass to 7mm Remingtons by just dumping some Bullseye loose into the case with NO FILLER OR ANYTHING ELSE, repeat, NO FILLER. This worked fine for neck-expanding. I didn't notice any particular problem with fouling on that occasion.

I'm fire-forming .375 Ultramag brass to create .404 Jeffery cases. After die-sizing until the bolt BARELY closes with a bit of effort on the new brass, 20 grains of 2400 and a full-case "charge" of cornmeal irons out the case beautifully. Firing vertically gives perfect case mouths, no trimming required, but for some reason firing these case-formers horizontally gives uneven mouths.

Fire-forming is a useful technique.

[Bullshop]

schuetzenboomer
What calibers are the first and last in that line up?

[SCHUETZENBOOMER]

Left to Right

6mmGP
250GP
6.5GP
270GP
7mmGP
300GP
8mmGP
330GP
350GP
375GP

[Bullshop]

I would much like to see the ballistics of the 6mm. I suspect it is about the same as the 240 Weatherby.
I have a 375 Scovill and suspect your version will do about the same. Mine is every bit the equal of the new 370 federal, same bullet weights to the same velocities.
Do you have a reamer for the 6mm?
BIC/BS

[405]

SBOOMER,
Yes, that's why it pays to pay attention to details in fireforming. Likewise I've learned the hard way with a couple of regular to Ackley fireforming projects.

In the case of the original post, if the parent case is correctly headspaced to the chamber or with the easier more positive system of headspacing on the belt (with correct headspace), then it's a relatively simple operation. The problems really show up for those viewing these types of threads then applying one simple, easy, quick and cheap technique to cover all fireforming jobs. The devil IS in the details. :)

[SCHUETZENBOOMER]

Lyle,

Sorry for a partial hijack, although all the following are fireformed or sized up/down from fireformed cases.

Bullshop,

I am attaching a spreadsheet of my load data. As you can see, I have no data for the 6mm, 270, 7mm & 300. Lack of time and too many projects over the last 5 years. I believe the 6mm will be somewhat overbore and hence inefficient (by my standards). Comparing the remainder of these loads to factory cartridges shows excellent efficiency in my GP's. Most will duplicate existing rounds on noteably less powder. All loads represent a minimum of 10 shots, others considerably more. The 6.5 is a tackdriver in most loads and several loads show single digit std deviation. I have shot several 1/2 & 5/8" groups at 100 yards. With few exceptions, I am no where near max loads for any of these loads in my rebarreled Mausers. Feel free to PM with questions.

Oops.....Looks like someone will have to tell me how to attach an excel file.

[SCHUETZENBOOMER]

Bullshop,

I forgot to answer your reamer question. I have a modified .257 Robert's Ackley Improved reamer with neck and throat removed and body re-tapered to maintain base case dim. With proper pilot, I can ream all body's regardless of caliber, then go back with neck and throaters to suit. All the GP's have identical shoulder height, meaning neck lengths vary by caliber. Go back and look at the pic for a visual. All my GP's are based on the .257 Robert's AI with the shoulder pushed forward another 2mm.

[SCHUETZENBOOMER]

as promised.

Top case....NO external indication of separation, but can detect same with hook scriber.

Bottom case, no expanation needed. Not annealed, fast powder and light bullet. I lost 50%+ this way.

[Bullshop]

Ever hear of the 224 Clark? It is also on the IMP. Roberts case. I built one on a Sako L61 with a 30" Lilja barrel with 1/9" twist. It was built to shoot the 69gn Siera fast. It works!
BIC/BS

[lylejb]

It's a LOT less work to just neck down .338 brass or neck up 7mm Remington Magnums

I don't understand how that could be. The reason I was thinking 300 win mag was because it is so close to 308 norma. It would just be pushing the shoulder back, trim shorter, and expand out the body slightly.

I don't see how starting with 338 or 7mm could be easier than starting with 30. I must be missing something.

In any case, we will be buying new or once fired brass to do this with. While 308 norma mag brass is occasionally availible ( not too often) it's 2x-3x the price, or more.

This rifle actually belongs to my neighbor. He had to leave this one in the safe this hunting season, he couldn't find ammo. That renewed his interest in reloading. He won't be shooting nearly the volume we do, he just wants to have a supply of ammo on hand. 100 - 200 rds would make him happy, I'm sure.

[badgeredd]

as promised.

Top case....NO external indication of separation, but can detect same with hook scriber.

Bottom case, no expanation needed. Not annealed, fast powder and light bullet. I lost 50%+ this way.

That's a great illustration of the reason NOT to use a fast powder. I had a similar experiece forming some cases. A medium to slow burn rate powder does use more powder but the case loss with fast powders, is more than adequate to offset the cost of the powder. Ackley probably blew up more guns intensionally finding safe margins for his gunsmithing than anyone else has even thought of. I readily will bow to his experience and suggestions. Another of his methods of fire-forming in cases that displaced the shoulder was the use of a false shoulder to ensure the case wasn't driven forward initially by the firing-pin impact. It seems to me that we should take advantage of his profound knowledge and follow his techniques.

Edd

[405]

Yes badgeredd! Finally to the bottom line of all this. Keep that case head back against the bolt face when the firing pin drops and the large impulse thrust of the primer forces the case forward. Use heavy bullets, slow powder. Anneal necks and shoulders if needed. Thanks for posting the pics there SBOOMER!

[madsenshooter]

Timely. I'll be fireforming some 6mm/30-40 Ackley Improved soon, and I had some thoughts of using some Blue Dot or 4227 loads to do it, think I'll change my mind about that.

[Bullshop]

lylejb
I think what he meant was that the 7mag and 338 mag are closer to the correct length starting out.
I use 338 win to form 358 Norma. They come out a tad short but its a simple conversion. I too could use 300 win mag for the 358 Norma but then there is that blasted trimming. I generally choose to live with the slightly short case and for go the trimming.
One of my favorite cases to re form is the 458 American. You can use any case based on the belted H&H head. Its a scroungers dream.
BIC/BS

[lylejb]

So, It would be easier, and safe, to just size down a 338 win mag then load a full power hunting load, like 70gr of 4350?

The case would be about .060 short, but I'm not too worried about that. It's the shoulder I wonder about. The case would be expanding ( if I remember right) about .060 right before the shoulder, as the norma has less body taper.

Is that right?

[swheeler]

So, It would be easier, and safe, to just size down a 338 win mag then load a full power hunting load, like 70gr of 4350?

The case would be about .060 short, but I'm not too worried about that. It's the shoulder I wonder about. The case would be expanding ( if I remember right) about .060 right before the shoulder, as the norma has less body taper.

Is that right?

No. I think the 338 case is actually a couple thousanths larger in diameter at the shoulder than the 308NM. .489/NM and .491 338WM

[lylejb]

Actually, the speer #11 manual has it the other way around. But now that I look, it's alot closer than I thought, .009 larger for the norma.

The brass will be run through a full length sizer die before firing, so even if I did run into oversize brass, it would be taken care of.