What grade bolt is best for die making?

[corbinace]

I would like to make a forming die for brass shotshells, from a 1-1/2-12 bolt. This die will reduce .0650" OD shells to .614".

What grade of bolt is best for abrasion resistance? Is it even a factor to consider? I do not want it to embed particles and scratch subsequent cases.

Is it even a factor in what I am trying to do.

I know a grade eight is stronger in at least tensile strength, does it still give the best performance for my intended use?

[JSnover]

Tensile strength increases as hardness increases but surface finish might be just as important. If you're not able to heat-treat your die, make sure it's well polished. The guys on the Swaging forum could probably tell you exactly what you need.

[Idz]

Unless you're going into mass production even mild steel will work fine for forming brass shotshells. You're not going to be able to embed brass into even mild steel. If you really want commercial production dies you can use a case hardening compound which will give you a harder surface than a heat treated and tempered die.

[skeettx]

Sorry for being so nosey but are you trying to attempt in taking .650 to .614 in brass hulls??
You trying to take 24 gauge down to 28 gauge??

http://www.midwayusa.com/product/679947/magtech-shotshell-hulls-28-gauge-2-1-2-brass-box-of-25

The body is much easier to take down than the head of the brass!!!

If you have 24 gauge brass hulls, how many do you wish to sell??

Mike

[M-Tecs]

Grade 8 will be the most abrasion resistant.

[country gent]

For hardness an allen head bolt is harder than most hex head bolts but will also be harder to machine. Pre hardened 4140 runs about 47 rockwell and would be easier to work with. Single point or chase the thread and work it to what you want. Its already hardened and some is stress relieved also so once machined its done no hardening tempering and finishing. Cold roll will size alot of cases before wear becomes an issue and if brass is clean grit shouldnt be a issue. A good radious leading in well polished and flowed out is mandatory here as any sharp edge corner between will tend to want to grab and scratch cases. I would bore to with in .002 - .003 size then slowly polish with fine sanding papers low rpm high feed to finish and size. last polish would be simichrome, flitz, or jewelers rouge ( red) on a soft clean piece of flannel to a mirror finish. Another thing to keep in mind is if this is a straight case ( no taper to sides) then the first .150-.200 of the die is doing 90% of the work. A standard cold roll bolt could have a 3/8" thick hardened ring fitted into the end and machined ( think carbide pistol dies) and machined to what you want giving a nice hardened sizing ring and softer more forgiving die body above. This ring could be threaded in to the body left long to tighten into place machined and radioused out with the die body in one shot.

[corbinace]

Sorry for the tardy reply, but life got in the way.

Skeettx, nosy is not a problem.

I am trying to form a slight neck for a .577 snider cartridge on 24ga shot shell cases. The shells only need about 5/8" of the neck reduced, so it should be a pretty easy task. Sorry, I do not really have an overabundance of extras. I have 25 used cases that are in various states of disrepair and 50 new untrimmed brasses. With the thin walls and my slow learning ability, I think I should stand pat. Brownell's show them in stock at the moment for $28.

The commercial dies size the case way too small for my .600 conical bullet. I need to size the brass each time I load because chamber is large and the case opens up too much to hold the bullet. After the initial sizing on the new brass, it will barely move it at all.

I do not have the skill set to case harden the die and with the limited production I think it would be overkill. How many .577 Sniders can a person load in one lifetime?:Fire:

Thank you one and all and please accept my apology for not responding in a timely manner.

Tim.

[skeettx]

Use an RCBS Bullet puller die body and it will do what you need done.
Start SLOW and work up.
http://www.sportsmanswarehouse.com/sportsmans/RCBS-Bullet-Puller-Body/productDetail/Reloading-Tools/prod9999004477/cat130001

Mike

p.s. I had a mould opened up to .600 and it works GREAT

BUT also my dies were made in England for a .595 bullet and they work just fine

[dkf]

Problem with grade 5 and grade 8 bolts is the surface finish often isn't so great when turned. For a die you want the inside to be nice and smooth. You'd be better off IMO to get a piece of 1 1/2" 1144 prehard and machine the die. The 1144 prehard is 30Rc, not as hard as a Gr5 or Gr8 bolt but the machinability is superior on the 1144. You'll get quite a bit of use out of the die at 30Rc.