Reloading Die

[DebosDave]

Well, I had an AR built in a caliber of my own design recently. I ordered and chamber reamer and re-size die reamer at the same time. The rifle is complete now, but I can't shoot it until I finish the resize die so I can fire-form some cases. I thought I would show the progress here.

I first attmepted to make the die by drilling, reaming, then chamber reaming the inside first. I then chucked up a dead center in the lathe and put the die between the dead center and a live center in the tailstock. The dead center I made was too soft, and when I was attempting to turn the exterior of the die concentric with the chamber, it held up and galled the chamber end of the die on the dead center.

I then decided I would work on the exterior first, and then drill, ream and chamber the die afterwards. This is what I have so far, with the exterior turned. I left extra length on both ends. On the chamber end, I will deep chamber, and then trim to length. The other end is non-critical length wise, as long as the decap/exapander stem will reach.

I wasn't happy with how the threads turned out, the rest of the die turned real nice and left an excellent finish, but the threads look galled on the side where the cutter advanced. I wish I could have cut the threads at a little higher RPM, but for course threads, my lathe specifies RPM under 225. This left me turning them at under 200 RPM for them. I did use a high-speed cutter, not sure if that helped or not. At any rate, here is what I have so far:

http://i42.tinypic.com/2jdnfih.jpg

[JCHannum]

The threads do not look all that bad. Depending on the material, threads might not always turn out as nice appearing as you might want. The important part is how well do they fit the nut and reloader body? There is not a great deal of force involved and as long as there is not too much shake, they will work just fine.

When threading a material that likes to tear, I usually make two or three passes without advancing the compound when getting close to final depth and then take very light cuts. Do not hesitate to use a three cornered file to clean up a threading job. I also flat the sharp V with a flat file when done.

[DebosDave]

They didn't turn out un-usable, but not how I would have liked. I did top the threads with a file when I was done, and the fit to the press and lock ring are great. It just doesn't look the best LOL.

[rws]

So, once you ream the die, what will you do to harden it? Looks fine to me, although I don't like the Hornady style decap rod.

[deltaenterprizes]

That looks like a LEE style decapper to me.

[DebosDave]

So, once you ream the die, what will you do to harden it? Looks fine to me, although I don't like the Hornady style decap rod.

Well, I am likely going to use a torch and oil quench, then draw it back in my kitchen oven. It doesn't have to be exact is my understanding, but I could be wrong, good thing, other than time which equates to experience, I have little money into the thing, so I can build another easily. I have a friend who has a heat treat oven I have access too, but will try the torch and over trick first.

[chriskat]

I might have missed it but what material did you use for the die? Given that you will be heating and quenching in oil I'm assuming it's oil hardening drill rod?

I've read, somewhere can't remember where, that dies don't need to be hardened since you are using steel to shape brass. Anybody got a comment to that? Only issue I can see is grit in the brass scratching the die. Do you think hardening would be necessary if the die was made from 4140 pre hard?

Jeff

[DebosDave]

I used a piece of 12L14, I understand it is oil quench. As to hardening I think the issue may lie with the carbon or other residue and not the brass itself. I suppose if you got it exceptionally clean, there would be little cause for scratching the inside of the die. I don't know. Callahan die blanks state they don't need to be hardened either, but I don't know what they use for the material. It is standard practice with commercial dies to harden them, so I am going to give it a go. This is all more for learning and trying than for a commercially sellable product, so I think it would take a lot to disappoint myself with the results :)

[JCHannum]

12L14 is hardenable with oil quench. It probably should be drawn back by heating and holding at 500 or 600 degrees F. The inside of the die can also be hardened with Kasenite. This might be simpler to do as it is a one shot process.

I don't know if all dies are hardened, I have heard that some are left soft purposely. I can't say how true this is, but in reality, only the full length resizing die needs to be hard. As long as care is taken with clean brass and lube, for occasional use, a unhardened die will last a while.

You might want to leave it unhardened initially incase modifications are needed.

[rws]

I've never hardened a die myself before, but my understanding is when it is heated to the proper temp, it scales quite a bit, and you have to deal with that once you're done. Heat treating shops use a vacuum furnice, and the scale problem isn't there.

Now, one other option is to have the die coated with TIN or similar, instead of heat treating.

JC is right, only a sizing die needs to be hardened.

[JCHannum]

Scaling can be a problem, particularly with using only a torch. This is another plus for Kasenite, if applied properly, it will prevent or greatly lessen scaling of the hardened surface.

[ulav8r]

"HEAT TREATINGAlthough 12L14 will respond to conventional treatments, it is not considered to be a case-hardening steel. Better results can be obtained with 1117 or 1018."

Taken from http://www.speedymetals.com/information/Material38.html .

At .14% carbon content, 12L14 will not harden enough to be noticable, even with a water or brine quench. To get useful hardness will require case hardening. If you need a hardened die, the best easy choice would be prehardened 4140-4143. It is relatively easy to machine and would be ready to use without more treatment.

[argon99]

If it was me I would hard chrome plate the die. This will give a good surface for the brass to form against and you know it will work without a lot of hassle trying to get the die hard when it's really not needed.

If you can find someone that does it you can use Boron Nitride Electroless Nickel plating. This will give a finish that will not require you to lube your brass before resizing. Getting the case lube off before reloading is the part of reloading I dislike the most. And if you do not get the lube off your bolt thrust goes up a lot and accuracy suffers.

[ironmonger]

That 12L14 is not going to respond to any quenching other than possibly super quench.
See this thread:
http://forums.dfoggknives.com/index.php?showtopic=5750&st=20
Hardening 'mild' steels is problematic at best and even the super quench was designed to harden higher carbon steels for special applications. The 4140 series would be much better, and can be machined annealed or normalized then hardened and tempered later. 1045 carbon steel might not be tough enough for dies, but if it is it can be oil quenched and used as is without tempering for many applications. The 1085 steels are more for cutting tools for wood and such any more as the alloy steels have pretty much replaced them for dies and such. Much easier to work with. I used some 4340 for blacksmithing dies, and was able to get away with water quenching them... nothing blew up when they were hardened, and they were then drawn with a torch... not critical stuff, and easily replaced if I screwed them up. Not so with your dies. If you elect to case harden them, they would most likely stand up to die use, but the surface finish will be a dog to try to maintain.

[DebosDave]

Thanks for all the input on the 12L14. I think I am going to go the Kasenit route as that seems to be the easiest with the most reliable and predictable results. I already have the material and the die is pretty well made already, so Kasenit will be the avenue this time.

Thanks again!

[gldwight]

Dave:
Please let us know how things turn out when you're finished.

IF it was me, I'd use water hard drill rod & bake it in the oven.
I've made quite a few items with it and they've turned out to be quite hard.

IF RCBS lube is used on brass. It's water soluable. Just rinse it off with hot water and then dry it real well. In the winter I set a batch of wet brass on the heat register over night.

OR in the summer, set it in the sunshine several hours during the day.

You do very nice work it looks like. These dies should turn out well IF your toerance's & measurements are correct size for the cartridge used.









Thanks for all the input on the 12L14. I think I am going to go the Kasenit route as that seems to be the easiest with the most reliable and predictable results. I already have the material and the die is pretty well made already, so Kasenit will be the avenue this time.

Thanks again!