Necking down for a wildcat

[Hengehold]

When creating a wildcat case, many times there is an option to use a parent case that needs to be necked up in caliber or a different parent case that needs to be necked down. Are there any inherent problems with the necking down in size?

To illustrate my question, think of making a 6.5-08. For example, using a 308 Win case and sizing the diameter of the neck down to make a 260 Rem rather than using a 243 Win case and opening the neck diameter to make a 260 Rem.

Thanks,

-TH

 

[jepp2]

Are there any inherent problems with the necking down in size?

When necking down the brass has to go somewhere. The more you go down the thicker the neck is going to be. I like to go down in neck size in steps. Prevents wrinkles and I think it distributes the thickness more evenly. YMMV

 

[ShootDots]

If you look on the "Search Forums" and find the title "308 FL Type S Bushing Die for 260 Rem." and scroll thru it til you come to my posting on there. I laid out in great detail the "step-by-step" process to take .308 Palma Brass down to PERFECTLY FORMED .260 Rem brass. If you follow the procedure as listed, you will come out with PERFECT brass.
http://forum.accurateshooter.com/threads/308-fl-type-s-bushing-die-for-260-rem.3925302/
^^^^^ Above is the correct thread...

 

[yotehater]

Given the choice I prefer to neck up.

Turning necks on brass necked down is time consuming. Then the possible dreaded donut from the thick shoulder junction.

 

[okie]

is .260 rem brass scarce??

 

[okie]

is .260 rem brass scarce??

oh, you want the small primer.

 

[mrjdasr]

When creating a wildcat case, many times there is an option to use a parent case that needs to be necked up in caliber or a different parent case that needs to be necked down. Are there any inherent problems with the necking down in size?

To illustrate my question, think of making a 6.5-08. For example, using a 308 Win case and sizing the diameter of the neck down to make a 260 Rem rather than using a 243 Win case and opening the neck diameter to make a 260 Rem.

Thanks,

-TH

just finished this exact thing [80 .308 military to .260 Rem] did it in two equal steps never lost a case
i do have an advantage, i have a lathe and can make my own bushings

 

[ncboiler]

oh, you want the small primer.

Or just buy it with the small primer already to go...

https://store.alphamunitions.com/product/260-remington-srp/

 

[okie]

Or just buy it with the small primer already to go...

https://store.alphamunitions.com/product/260-remington-srp/

thats good to know

 

[okie]

the info. you got here is sound--always easier to go up in my exp.

 

[Ray B]

Necking up or down requires a tapered expander or die with shoulder angle 25 degree or less. Necking down 308s to 7 mm or 6.5 will work with the standard die because the shoulder slope is gradual enough that the brass follows the die into the neck. If necking a case down to one of the improved sizes with 30-40 degree shoulder angles, the result will be several squashed necks because the angle was too steep and pushed the brass down instead of in. In those cases, a forming die is needed.

 

[Hengehold]

Necking up or down requires a tapered expander or die with shoulder angle 25 degree or less. Necking down 308s to 7 mm or 6.5 will work with the standard die because the shoulder slope is gradual enough that the brass follows the die into the neck. If necking a case down to one of the improved sizes with 30-40 degree shoulder angles, the result will be several squashed necks because the angle was too steep and pushed the brass down instead of in. In those cases, a forming die is needed.

What is a forming die and how is it different than the FL sizing die that one would use for resizing brass for the wildcat? Does the forming die have similar body dimensions as the wildcat with a more gradual shoulder angle such as a 25degree shoulder rather than a full 30 or 40 degree shoulder?

-TH

 

[dkhunt14]

What is a forming die and how is it different than the FL sizing die that one would use for resizing brass for the wildcat? Does the forming die have similar body dimensions as the wildcat with a more gradual shoulder angle such as a 25degree shoulder rather than a full 30 or 40 degree shoulder?

-TH

It is usually a series of dies or bushings made to take it down in steps. There is a guy here that sells them. Matt

 

[fguffey]

Are there any inherent problems with the necking down in size?

Reloaders have lots of assumptions. I have formed cases to wildcat cases, I have one that I form cases for that dies not go up and or down, I have never assumed "here is what happens"; the case length shortens .045" from the end of the neck top the case head.

I have never assumed the case neck got thicker and or thinner, when I neck a case up the neck shortens. when I neck a case down the necks gets longer. I know and understand, it sounds cool with thicker and or thinner.

And then there is that part about choosing another case: The neck on one of my wildcats shortens .045" in the forming process. The neck on that chamber is .217", that is short. I am told the 300 Win Mag case neck is short at .267", if that is true .217" is shorter. So I choose to from 280 Remington cases, the Remington case is .041" longer than the 30/06 cases.

F. Guffey

 

[fguffey]

What is a forming die and how is it different than the FL sizing die

The forming die forms the case, after forming it is necessary to size the case with the final sizing die. That is one of those foot notes in the RCBS Special Order Catalog. I believe I am the only person on this forum that orders the catalog every year.

There are cases that do not require forming, the foot notes in the catalog list them as foot note #1, by now that could be hash tag ONE.

F. Guffey

 

[KMart]

It is usually a series of dies or bushings made to take it down in steps. There is a guy here that sells them. Matt

Pbike on this site makes one that uses bushings. Works very well.

 

[dkhunt14]

Pbike on this site makes one that uses bushings. Works very well.

That's the name, couldn't think of it. Matt

 

[dkhunt14]

I have never assumed the case neck got thicker and or thinner, when I neck a case up the neck shortens. when I neck a case down the necks gets longer. I know and understand, it sounds cool with thicker and or thinner.

F. Guffey

You must of never measured neck thickness with a ball micrometer. Every case I ever necked down a size gained .001 thicker. If the case was .015 on the thin side it was now .016 and where it was thicker like .016, it went to .017. That's why sometimes they need turned after necking down. Matt

 

[dmoran]

Sizing/forming down cases can be very problematic to achieve consistency from case to case. Inconsistent volumes plague capacities, shoulder and neck junction inconsistency plague wall thickness, etc.. To get consistent sets from forming down, can demand a lot of cases to be made, that then need to be heavily qualified and segregated, to get case consistency to a set. Basically, forming cases down is old school, in terms of accuracy advancement and achievement.

Expanding cases out, has proven to be less problematic to achieve consistency from case to case. That is basically a continuation of how cases are made (not a reversal as is forming down). Wildcatting by fire-forming, or other expansion methods, has pretty much retired "case forming" when it comes to case consistency and achievable accuracy there after. And is why "Ackley Improving" became so popular over the years, and remains so popular yet today.

My 2-Cents
Donovan

 

[Hengehold]

Sizing/forming down cases can be very problematic to achieve consistency from case to case. Inconsistent volumes plague capacities, shoulder and neck junction inconsistency plague wall thickness, etc.. To get consistent sets from forming down, can demand a lot of cases to be made, that then need to be heavily qualified and segregated, to get case consistency to a set. Basically, forming cases down is old school, in terms of accuracy advancement and achievement.

Expanding cases out, has proven to be less problematic to achieve consistency from case to case. That is basically a continuation of how cases are made (not a reversal as is forming down). Wildcatting by fire-forming, or other expansion methods, has pretty much retired "case forming" when it comes to case consistency and achievable accuracy there after. And is why "Ackley Improving" became so popular over the years, and remains so popular yet today.

My 2-Cents
Donovan

I did not realize that, thank you for sharing.

-TH