forming dies

[Rayant]

Are the second forming and trim dies different from the initial form die? Or is the form and trim die really only a trim die. RCBS and Redding list a form then another step the form and trim die. I guess what I'm asking is how much difference is there between the two dies, or is it you trim with the form and trim die.

[Mk42gunner]

Depends what caliber you are forming, and from what caliber. Many times you cannot go straight from one caliber to another in one step, such as forming .256 Win Mag from .357 Magnum.

What are you trying to make?

Robert

[samari46]

Years back when only Norma 7.65x53 Argentine Mauser cases and non corrosive ammo were available I bought the neck,FL,and seater die set and a form and trim die as well. Made cases up from boxer primed Israeli brass which at the time I had about 400 of. I sized them and then while still in the die cut off what sticked out of the die and filed the rest. Started out with only a few so could adjust the form die to give a slight crush fit in the chamber. One thing you may want to think on is will your cases need neck reaming. Remember you are pushing the case neck down to where the brass is thicker, hence the neck reaming.still have all 4 dies and a decent amount of both Norma and PPU brass for the 7.65x53mm. This only one case forming story.Others may do it differently depending on what on what they are trying to accomplish. Necking down the parent case, necking up the parent case or in between. Frank

[Rayant]

Mk42 gunner-- If you look at the Popular case forming dies on the Redding website look at 221 from 222 or 223, 25-23 from 30-30 what is the difference between the form #1 and the form and trim. Is there a difference in the shape of the cartridge case? or is it you can trim with form and trim die?

[Mk42gunner]

Like I meant to say in my earlier reply, incremental steps. The form die #1 partially forms the new case, the form and trim die finishes it, (and you can use a hacksaw and file to trim excessive length) then at least with the Redding dies you still need a full length sizing die.

Hope this helps,

Robert

[Bent Ramrod]

The ones I have and have seen try to divide the forming into steps, arranged in such a way that the minimum percentage of cases will be spoiled by the process.

For instance, the first die will move the shoulder back without affecting the neck diameter. The second will begin to reduce the neck diameter, leaving the case mouth slightly tapered towards the final diameter. The third one will fully form the neck down to the new shoulder, leaving the excess projecting from the die for filing and trimming.

Some of them have little reamers in the necks to reduce neck thickness. Most leave the case body somewhat tapered, to be loaded and fire-formed to chamber dimensions, which are duplicated by the sizing and seating dies in the accompanying loading die set.

Starting the donor case into the form/trim die might work, or might mangle the case, depending upon the modification and how it is done. Sometimes, gradually screwing the final die down while gradually sizing the case, will work (mostly), but then there is the time element to consider.

How much of this reforming operation can be mimicked by the use of standard dies depends on the percentage of cases the operator is willing to see scrapped during the forming process.

It just depends on what one starts with and what one wants as a result. I once saw a magazine ad for a Pacific Super Deluxe loading press that had a .30-06 case in the shell holder that had been crammed into a .250 Savage sizing die to form a .250 Savage case with an impossibly long neck. The ad copy said the press was powerful enough to do this in “One Pass!”

Always wondered how many tries they made to get that one case to go. The operator must have had arms like Popeye the Sailor.

[EDG]

The #1 form die can vary from set to set. Usually it has a significantly larger neck than the #2 die or a trim die. A #1 form die for a tapered straight case like the .40-60 or .40-65 Win is just a larger neck (than the FL die) with a tapered interior. My die set used to form 250 Savage from .30-06 has several form dies that push the shoulder back and reduce the neck diameter in steps. Once the neck is small enough it goes into a reamer die that is approximately the same as a FL die with a reamer guide on top.

Some times RCBS refers to the trim die as a form and trim die but they always seem to be just a trim die.
The RCBS trim dies that I have are all close to FL die dimensions except for the neck. The neck usually measures .010 larger than the RCBS FL die.

My other brands of trim dies vary all over the place and I do not have enough of them to say exactly what to expect.

If you have more questions I can check my dies and get back to you.

Mk42 gunner-- If you look at the Popular case forming dies on the Redding website look at 221 from 222 or 223, 25-23 from 30-30 what is the difference between the form #1 and the form and trim. Is there a difference in the shape of the cartridge case? or is it you can trim with form and trim die?

[Rayant]

Thank you Bent Ramrod and EDG, you answered my question. I have several sets of forming dies and was wondering about this. I have been watching you tube and everyone does it differently. I have come to conclusion that it is important to anneal your brass. Thanks again.

[fguffey]

I guess what I'm asking is how much difference is there between the two dies, or is it you trim with the form and trim die.

I suggest reloaders order a Special Order catalog from RCBS: The number for the trim die and forming die is the same.

And then there is utility; I have 16 forming dies, we all know that is not enough but some forming dies can be used to form other cases; it helps when the forming die is short. My favorite forming die is the 308 W forming die, if I only had one forming die it would the 308 W forming die, if I only had two forming dies the second forming die would be the 243 W forming die.

And then there are others I can not do without for the same reason; they are short.

F. Guffey

[blackthorn]

Post #8: "I have come to conclusion that it is important to anneal your brass. "

Certainly, some amount of annealing your brass may be of use. BUT, if you do a full anneal on your case neck(s) you increase the chances that you will collapse the case neck on the first pass. I have had better luck either not annealing at all, or rather doing a partial anneal (tempering if you will). I anneal by dipping the case neck into 700 degree lead and experiment with timing to get the amount of anneal I need. I save old, useless cases to find the amount I need.