A different for method for neck sizing brass
 

I picked up a 280 Remington and noticed I don't have a 280 neck sizing die. :sHa_sarcasticlol:
So, I put the shellholder in the press for the 280 and threaded the 7mm mag full length die in, I then ran the 280 brass into the 7 mag die and voila, neck sized 280 brass.:sHa_shakeshout:
I didn't need to lube the cases as the 280 is quite a bit smaller in diameter and didn't touch the inside of the 7mag die, it did the same thing as a 280 neck die would do.
I have never done that before with 280 brass, it works.:sign0111:

Are they still concentric?:confused:
Cat

Exactly what I was wondering.

Me as well.

Yes, the shellholder for the 280 kept them straight. I was curious to see if they would stay concentric as well, it seems to work.
I am going to see if it is accurate, that will tell.

Did you spin them with a dial indicator or eyeball them?
Shooting them will certainly tell the tale however.
Run a few groups of five neck sized and a few groups FL sized i your 280 dies, that should tell you what you need to know.:)
Cat

The brass went straight into the 7mag FL die as it would on a 280 neck die, the 280 doesn't touch the case wall at all, that's what gave me the idea of using the 7mag FL die.

Just finished reading somewhere of someone else doing the same thing.

I have done it before as well, but just for fun, to make dummy rounds for wildcats that cross my mind. Not live ammo i plan on shooting groups with.

Why not just back your FL die off the shell holder 1/2 turn or so?

How do you know they are concentric?

it works better with seasoned brass,,or brass thats bin fired a few times..
i have run into problems ,with annealing it then sizing it .necks are to soft.
better so size it first before annealing ,....
i use the 7wsm die alot the wetherbys have long necks and work great .for doing this kinda stuff.

Such techniques were common practice from the time the brass case was invented. While it is unlikely that sized cases are perfectly concentric, it is a method which can work well in a pinch. Neck sizing dies, such as those which were supplied by RCBS for years, also offered little support to the case body and frequently produced eccentric necks.
Neck wall thickness almost always varys from side to side. Consequently, when the neck is sized without some lateral support for the case body, the neck is likely to end up with a bit of off set. Interestingly, this offset is in a direction which mitigates some of the eccentricity of the inside of the neck so the bullet itself could end up being better aligned. I make no claim that this is actually the case however. Perhaps I'll do some testing to determine to what extent this occurs.
In the end, I don't necessarily consider loading 280 ammo with 7 Mag dies to be good practice but I don't condemn it out of hand. A person can do things however he wants as long as it is safe (this is). If the performance of the system is good enough for him, it's good enough, period. Leeper

Hi Leeper, I'm not loading ammo, just neck sizing the 280 with a 7mm mag FL die to see if it works.
I marked all around the 280 case neck with a black marker and ran it through the 7 mag FL die, it resized over 90% of the neck and the black marker was pushed down uniformly the same all way around the case neck.
This makes me believe it is going in straight and coming out straight, the case wall is not touched just like a 280 neck die would do.
Food for thought......:)

Because I only want to neck size, backing the die off still partially resizes the case body which I want to avoid.
And besides, eveybody does it that way........:2mo5pow:

Yup
I myself have used different dies when making wildcats or if I get a rifle that have to compromise with as far as loading goes
That is why I suggested he shoot them and compare!:)
Cst

Nothing new here. Load them up and shoot,accuracy will be as good or better than with cases that have been full length or neck sized with off the shelf dies.
I have shot out barrels on several wildcat cased coyote rifles with ammo neck sized with with nothting more than a universal die body and bushings and a Hornady floating bullet seater die.

At last, a guy who knows what the hell I'm talking about:sHa_shakeshout:

Sooo, how did they work?:thinking-006:
Cat

lee collet dies are like 20 bucks..they sell them ya know...at the store...

Done stuff like that lots of times.

Why wouldn't they be concentric?...unless the brass had uneven neck wall thickness before it went into the die.

303 Carbine,
I think everbody on the thread knows what the hell you are talking about. However, not all are clear on the concept of maintaining or improving concentricity and the part the body portion of the die plays in this.
First, it is important to understand that no die can fix brass which in which the inside and outside is not co-axial. So, while the outside of the case may be perfectly straight, the inside will remain eccentric. When a case like this is sized in a die which does not support the body (like a 7 mag die sizing a 280, for instance), the neck is likely to be reduced further on the thin side and end up offset in comparison to the body. The same thing can occur in a piece of well-used brass which has work-hardened to a greater extent on one side. Now, in the first instance, the outside of the case neck ends up eccentric to the body but the inside may actually be close to concentric than it was before. I believe I can demonstrate this but I have work to do first. I will get back to it.
Good, concentric brass will allow the production of concentric ammunition much more easily; even with half-assed methodology. Crappy brass is likely to produce crappy ammunition regardless of the method or equipment used.
So, as long as the brass is good, the neck is likely to remain concentric, just as Rembo has stated. If the neck starts out eccentric, it will probably remain so although the point of eccentricity and the amount may change.
When all is said and done, whatever works does just that; it works. When I was a kid, I loaded ammo for my 303 using a 300 Savage sizer to neck size because that is what I had. This was used in a Lyman nutcracker tool. I seated bullets with a 30/06 seater in the same tool. While none of this was geared toward the production of precision ammo, it worked well enough for me. I could shoot good groups and shot a bunch of gophers with ammo loaded this way.
Your method of sizing 280 brass in the 7 mag die will serve you well and your brass life will be better than if you fl sized. Keep on shootin'. Leeper

The reason I used the 7 mag die to neck size 280 is the 280 neck sizer doesn't touch the case body, neither does the 7mag FL die. So, I can't see the difference in the neck sizing process.

That's entirely correct. Functionally, there is no real difference. Neck sizing dies rarely offer any support to the body of the case. Leeper

Concentricity as with any other measurement is a function of tolerance. If your tolerance is 0.003" runout, then 5 thou isn't concentric, but 2 thou is. It all depends on what you intend to do with your bullets. The OP will not know whether the casing necks are concentric until he establishes his own tolerance and properly measures runout.

For my part, I would be more inclined to ensure concentricity within my tolerances rather than wasting powder and components downrange to be the indicator. There are other parameters which define repeatedness on paper besides concentricity. Seating depth, neck tension come to mind.

And this is the crux of the matter. Being cheap is expensive. I know because I've been a victim. That said sometimes ignorance truly is bliss. :)

I get a chuckle out of guys that tell themselves that they shoot a lot and that they know their schit, when in truth they would need a second job just to buy the primers that an avid shooter goes through annually.:)

Hi Cat,
My 280 (stamped 7mm Remington Express) just arrived this afternoon in the mail, I was keeping myself entertained with a couple different neck sizing procedures.
I have two sets of 280 FL dies for the cases that didn't fit as I had gotten some brass from a gunshow source.
All brass will be run through the FL die just to be sure of fit before hitting the range.

Now I really don't understand.

WHAT???

Hilarious.....:-)

Hey, I think I'll use my 280AI dies to neck size my 280 cases.....I do have 280 dies though.