Question about tight neck when resizing .243 down to .224....

[VaniB]

Yes I ran this question at the other websight too, but it's quiet about it:

QUESTION:

....when I leave the expander ball/rod out of my new Redding die, I'm getting about a .205 size diameter opening when sizing my fired .243 cases down to .224 cal. That's wayyyy tight. With the expander ball/rod applied, that .205 hole is pulled back open to about .222-.223

For comparison sake, I checked my Lee FL sizer in .223 calk to see that it sizes cases to only about .219 with the ball/rod left out.

So, I'm concerned that this expensive Lapua brass is really going to get squeezed and stretched back and forth in excess quite a bit.

At first I thought that this custom die was machined a bit too tight. But, is it just perhaps that .243 brass is a thicker metal mouth then .223Rem, and so this tight .205 opening is to be expected? I've also discovered that the expander ball pulling this mouth open really doesn't help with case concentricity either!







BTW....I'm just using old .243 brass for practice. The die is actually for a 22x47 Lapua. The brass is just as thick.

 

[mikecr]

Couple things;
-20thou is too much sizing for one bushing
-Brass thickens as it's downsized

You might pick up a Sinclair neck thickness gauge so that you can see this.
Don't forget about the loaded neck diameter/clearance.. It's likely that you'll need to turn the necks, unless the reamer accounted for very very thick necks(not the kind of chamber desired). Then you'll have a better idea about the bushings needed to get desired tension.

 

[keithcandler]

Van, try sizing down the brass with the bullet seater...

which is larger than the sizer.

You are probably in a situation where you are going to have to turn the necks or buy a Bushing die to accomodate the fat neck.

I do not know what the dimension of the loaded round would be in comparrison to the neck dia that the neck in your gun was cut with...very important to know these dimensions. You will know if the brass is too thick if the loaded round will not chamber in the gun, and DO NOT FORCE IT!

Be sure to put a heavy outside chamfer on case mouth before you neck it down, and lightly lube the neck.

Good luck!

 

[345 DeSoto]

Perhaps a Lee Collet Neck Sizer, in the appropriate caliber might help. Unlike a Bushing type Neck Sizer which indexes on the outside of the case neck, the Collet type indexes on the inside of the case neck. Then, all you would need to be concerned with would be neck wall thickness...which neck turning would remedy...

 

[VaniB]

Sorry guys. I see I haven't provided enough information to help you understand where I'm at. So let me fill you in;

The final intended cartridge I intend to make is a 22x47Lapua.
I'm starting with 6.5x47Lapua cases to make the final 22x47Lapua case

I do not have the rifle or barrel made yet. My intent was to make a couple of dummy rounds with all my new dies, cases and 75&80 Amax bullets, and send the dummy cartridges off to Dave to make a reamer. So luckilly, there is no barrel already made, or perameters I must adhere to yet.

I have a forster 6x47L FL sizer die which sizes the 6.5 x47 Lapua case down to a 6x47. I also have a new Redding 2 die set which includes a FL 22x47L sizer die, and a standard Redding seater die. THEN, I also ordered and have in my possession a $125 (ouch) Redding FL 22x47L bushing die. I did not order the bushings for it yet until I would know the aproximate case neck size.

So far, the Lapua cases, or the scrap .243Win cases are all being squeezed down to a .205 opening (with the expander ball removed) I've noticed that a 6.5x47 Lapua case starts out very straight, but ends up getting diostorted out of concentricity. It seems I read in another thread to remove the expander ball from the die and buy a Sinclair neck expander to prevent distortion caused by the pulling on the neck. I suppose fire forming would later remove a lot of the inconcentricity too...and then I can solely rely on the Redding FL bushing from that point on.

Anyway, this is where I'm at now, and wonder what you guys think.

I was hoping on having Dave make me a tight neck chamber, as I didn't want to turn case necks. But, I'll do that if you think it's necessary for me to obtain 5 shot 1/4" -3/8" MOA groups.

 

[mikecr]

I was hoping on having Dave make me a tight neck chamber, as I didn't want to turn case necks.

A 'tight neck' chamber means the brass has to be fitted because in standard form, it will not fit. Brass for a tight neck chamber IS turned.
It's a good move on your part to make ammo first.
But the chances of ending up right are pretty low if you don't make everything right. That means getting the right tools first(including books) and then deciding -up front, what it is that you want. Then simply make it that way(that's the easy part).,

For this;
I would be surprised if the neck thickness you're creating would group well. I'll guess that Lapua starting out ~13thou in 26cal will thicken to ~19thou by 22cal. ES will be ugly do to tension variance unless you constantly anneal.
Plan on turning the brass
The barrels will also burn up quick, so have atleast 2 barrels chambered at a time. Otherwise your gun will be out of service waiting for finished barrels more than it will be at the range shooting well.

Well, that's about all the fragmented notions I could put together now.

 

[VaniB]

I meant the chamber in my 20Tac is "tight" as in competition chamber tight, but not neck turning tight.

As well, I wanted to make the new 22x47 chamber "competition tight", not tight so that neck turning is required.

As far as burning out barrels, (which is a little off topic on this thread); This won't happen as quick, as you are suggesting. I will purposely be using 75-80 gr bullets at velocities maintained at or below 3,250- 3,300FPS. If I were to pursue pushing an extra 100FPS to 3,400+FPS velocities, then this would do the damage that you warn of.

Guess I'll call Redding and ask them if turning necks will be required. There's just way too much technical advice and discussion required to set me straight, and I can't blame if nobody desires to read such long posts, and have to write a book in response, like you did for me.

Thanks.

 

[henrya]

You're making this too hard.....

You're going to have to turn necks if you use that brass necked down to .22. I'd turn them while at 6mm to something like .010 and then size them down to .22 caliber. Maybe turn again after necking down.

A .22-250 Improved would be lots less work and give practically the same result. Order a reamer that's .002 over loaded round neck diameter which you can easily make a sample of since all you're doing is seating a bullet in a factory case. Send the .22-250 case in with the 75 grainer seated most of the way into the neck. Stay just above the neck shoulder junction.

Load 'em, shoot 'em and your cases are made. If you're not going all out I don't think you'll see any benefit from the Lapua brass. Even then maybe not.

 

[VaniB]

.....A .22-250 Improved would be lots less work and give practically the same result. Order a reamer that's .002 over loaded round neck diameter which you can easily make a sample of since all you're doing is seating a bullet in a factory case. Send the .22-250 case in with the 75 grainer seated most of the way into the neck. Stay just above the neck shoulder junction......

henrya,

As mentioned, I already purchased $250 in dies and another $100 in Lapua cases. I don't think I'll be switching to 22-250 at this point.

I suppose I need to call Dave at Pacific and ask him what outside diameter I ought to be trying to obtain with the 22x47 cartridge . I suppose if I'm going to have to turn case necks , then I I'll have a pretty good choice of diameters to choose.