Shortening a FL Die Question

[alf]

Bought a new AR barrel chambered in 22DTI, and dies are over $200 with a 4+ month wait from Hornady.

The 22DTI is just the 6.8 SPC necked down, with the shoulder changed from 23 to 30 degrees.

Sure looks like a shortened 22 Nosler die is the easy button.

6.8 case specs:

Shoulder diameter	0.402 in (10.2 mm)
Base diameter	0.421 in (10.7 mm)
Rim diameter	0.422 in (10.7 mm)
Rim thickness	0.049 in (1.2 mm)
Case length	1.667 in (42.3 mm)

Base to shoulder...........1.3012"
Base to start of neck.....1.4136"
Shoulder length........... .1124"

224 Nosler case specs:

Shoulder diameter	10.2 mm (.400 in)
Base diameter	10.69 mm (.4207 in)
Rim diameter	9.6 mm (.378 in)
Rim thickness	1.1 mm (.045 in)
Case length	44.7 mm (1.760 in)

Base to shoulder............1.389"
Base to start of neck......1.515"
Shoulder length............ .1260"


So the base to start of neck difference of the two cases is .1014".

So would cutting off .110" be the place to be?

 

[Rocketvapor]

Looks like it might work.
A Redding body die would be easy to shorten.
Then shorten a Lee collet die for the neck.
I shortened a .223 collet for 22N.
Less money to play with even if it didn't work.

 

[dellet]

You will end up with a very small base die after cutting .100” off the .200” base. The body taper will start .100” early. Basically you will crush the web area about the same as putting the case on top of the shell holder and running it into the die, which is .125”.

You might be better off cutting the die off a bit shorter and staying off anything below the .200 line of the case you are forming. Or only kissing it with the die.

A form and trim die might also be an option if one is made for the 224 Nosler.

 

[alf]

I should add, I'm not a machinist, so I'm not doing the work.

I was hoping for some feedback, & for some hard numbers to forward to the machinist/smith.

If the body taper was linear, there's .0207" taper in the Nosler's 1.389" length.

My virgin 6.8 brass measures .417" at the base, so .004" under SAAMI.

 

[NZ_Fclass]

If you have some ammo or a good drawing, perhaps a die could be made - Whidden and others?

 

[alf]

If you have some ammo or a good drawing, perhaps a die could be made - Whidden and others?

Whidden could do it off reamer print, chamber cast, or 3 fired cases, but 4+ months out & well over $200.

 

[alf]

I did order a set of 224 Valkyire dies last week, before throwing the Nosler in the mix, of which I just ordered.

The Valkyrie case measures 1.2033" from the base to start of the shoulder, which is .979" shorter than the 6.8 case.

My thought was I could run the case in just far enough to neck it down and form the shoulder. I figured that would get me going on load work while waiting on the dies from Hornady. The downside is fired brass not being sized at the web if needed for reloading, which sent me down the 22 Nosler path.

I have fired & virgin 6.8 brass, & it looks like the taper is linear, as best I can measure. If that's right, taking .100" off will leave the base 1.5 thou tighter.

I did do a chamber cast, but only for the neck dimension, not the base.

 

[dellet]

The problem with cutting .100” off the base of a die, is that it completely removes the the portion that would size the base.

If we define the base or web area as that from the bottom of the case to the 200 line, where any taper would start, a normal die will only touch .075” of that. The other .125” of the base will be in the shell holder.

When you cut .100” off the bottom of the die, you cut off the portion where the base diameter of the die would be, completely. The taper will start at .125” from the bottom of the case head instead of 200”.

The problem this creates, is that it is a lot harder to blow out the web area below the .200” line than above. So you are likely to get a bulge in the case right where a case head separation is likely to happen. Repeatedly sizing and blowing it out at that area will likely lead to short brass life. Since your use is temporary, until proper dies can be obtained. It may not be an issue, but something to be aware of.

You could also have the base diameter of the die opened back up by whoever does the shortening.

I would probably cut the Nosler die so that it does not size base at all when the shoulder is formed if I used it.

If the Valkyrie die will set the shoulder where it needs to be, I would lean that direction. Since the Valkyrie case is a larger diameter, you may need to use either the Nosler die, or a 6.8 die as a body die after forming the shoulder. The shoulder to body junction might end up being too large in diameter to chamber.

It’s not nearly as complicated as it sounds, but trial and error is unfortunately part of the process sometimes.

The other thing would be to not get discouraged by accuracy until you get a proper sizing die. Cobbling something together to fire form brass to a chamber is a lot different than actually trying to have good results on target.

 

[alf]

Thanks for taking the time to reply....

I decided to cancel the 22 Nosler die order.

I'm sticking with forming & seating with the Valkyrie die for now.

I ordered a stripped Lee 6.8 SPC full length die that I can get cut off, to size the web if needed.

How much work is it to get a carbide blade for the hacksaw & cut it in half?

 

[divingin]

You will end up with a very small base die after cutting .100” off the .200” base. The body taper will start .100” early. Basically you will crush the web area about the same as putting the case on top of the shell holder and running it into the die, which is .125”.

That assumes you size to the capability of the die. You should be sizing to get your base to shoulder correct, which means you won't be running the die against the shellholder.

Raises another question: Are dies cut with a compound taper from the die mouth to the shoulder? Or is it a simple taper?

 

[Loggins J]

Give Harrell s precision a call they may be able to help you

 

[dellet]

That assumes you size to the capability of the die. You should be sizing to get your base to shoulder correct, which means you won't be running the die against the shellholder.

Raises another question: Are dies cut with a compound taper from the die mouth to the shoulder? Or is it a simple taper?

I explained in greater detail in post #8.

The original question is what will happen if he cuts .110" off the base of the die, to get the shoulder and neck where he wants it. If he does that, he will likely need to bottom the die out against the shell holder..

Because that length takes off the base of the die past the 200 line, if he sets the die up to contact the shell holder, it could taper everything above the shell holder .003-4" more than a regular die.

That's why I suggested taking off more than the .110" to make sure it would stay off the base, or at least getting rid of the taper and restring the .200" line.

It could be better or worse, depending on the die he starts with.

 

[geo.ulrich]

Wow you guys make stuff really difficult. Face the die and polish it open to dia. needed... I guess there wasn't any wildcats being made until the factories would make dies for you...

 

[Uncle Ed]

Remove slightly less off the top of the shell holder and fine tune it and see how it works. The shell holder could be fine-tuned and be far cheaper than screwing up a good die. I have removed .003 to .005 off a shell holder but never more than that but it still makes for a cheaper screwup.