Lapua, up or down? 260 Rem

[xtratoy]

When using Lapua brass to form 260 remington is it better to go up from .243 or go down from .308 brass? How many transition steps are required to resize the neck? Does the neck get thin stretching up to .264 from .243 or is it not an issue?

 

[ol mike]

Re: Lapua, up or down?

I'd say go up -243 to 264 -skip neck turning.

 

[boomtube]

Re: Lapua, up or down?

Use 308 and neck down for your .260, for sure. The necks WILL NOT be too thick for any factory chamber.

Necks will get thinnner when necking up of course but there is an even more important consideration; consistancy. Even the most precise brass will not be totally consistant, in thickness or hardness, around the neck circumference. The thin/soft places will expand more than the rest so you will lose a LOT of the advantage of the money you spent on that excellant brass because when necking up, NOTHING supports the case as the expanding occurs.

But, when necking down, the case is fairly well supported by the die so the necks tend to be better centered and, as a result, more consistant. The little bit of neck thickening will make the case-to-chamber fit a little better too.

Ideally, you would use a 7-08 sizer as an intermediate step but I often make .243 (without a need for neck turning) from .308 in one step so it's not really important. Use a good lube (Imperial Die Wax or Lee) and size slowly, go down on the lever until it gets quite hard, then lift it up and let the lube spread a little and repeat the process until you are fully formed. And lube inside the neckswith a Que-tip so expanding will go well too.

You might want to anneal the necks after forming, otherwise your work hardened case necks will tend to split early.

 

[xtratoy]

It sound like necking down is the way to go. I could use a thicker neck. My Shilen barrel seems to have a generous neck as fired with Rem brass. .2915 OD on a loaded case versus .2975 on a fired case. I was hoping for a tighter neck but I guess on a production Shilen-Savage barrel they make sure anything will fit. Does anyone have any neck thickness dimensions on necked down brass compared to Rem brass.

 

[ICANHITHIMMAN]

I would neck up from 243. If you go down then you could get a doughnut and you will have to turn the necks.

 

[boomtube]

"If you go down then you could get a doughnut ..."

Huh? I assume you have read about it but done little or no such case reforming?

The "doughnut" you fear relates ONLY to making shorter case bodies where thicker body brass is forced into the neck. It has NO application to a simple neck-down operation such as we are discussing.


XTRA - "Does anyone have any neck thickness dimensions on necked down brass compared to Rem brass."

I doubt anyone has that as a data point! I suspect you could get close by measuring the current thickness and multiplying that by the percent of diameter change in necking the brass down, but that's only a guess on my part. I just do it and deal with whatever it is when done. On those rare occasions I do NEED to turn a neck it surely isn't difficult to do. Most such operations are done simply to clean up the thickness variations a little and I do that on all of my "precision" brass anyway.

I do quite a bit of case reforming for three cartridges just to get "tight" necks in my factory chambers . The need to turn is more determined, for me anyway, by the actual chamber neck diameter as found with a chamber cast. I don't pay much attention to the book specs for neck diameter of my finished loads, it's MY ammo and it's not to be used by anyone else.

After major case reforming of common brass, such as R-P 30-06, to .22-250, I do turn the necks after a light ream to remove any doughnut and smooth the inside. I usually turn to leave maybe .002-3" of clearance in my factory chamber necks, it does help accuracy, a little bit anyway. I have very few "flyers", which gives me a whole lot more confidence in my ammo.

Using the right dies (a Lee Collet neck die and a Forster seater), my loaded ammo with reformed brass, the runout is typically .0005-7", or pretty darn straight!

 

[xtratoy]

great info! I have another question. I have the Lee Collet die set for the 260 and I don't know if I can use that to resize. I don't want to jam a 308 shell up in it and bugger it up. does this require a standard bottleneck 260 die to perform the process?

 

[MagMan]

For what its worth the word is Lapua is making 260 Rem brass. Who knows when it will hit the open market though.

 

[KRP]

great info! I have another question. I have the Lee Collet die set for the 260 and I don't know if I can use that to resize. I don't want to jam a 308 shell up in it and bugger it up. does this require a standard bottleneck 260 die to perform the process?

You'll need a different die, Lee collet dies aren't made to do this. I've heard you can use a 7mm mandrel in a 308 Lee collet die first and then the 260 die and it works. A regular 260 neck or full length die would be easier though I think.

 

[boomtube]

"I have the Lee Collet die set for the 260 and I don't know if I can use that to resize."

KRP is correct.

NO neck die is useful in reforming, IMHO. The otherwise EXCELLANT Lee collet neck die would be the absolute WORST choice for any reforming! You will need a FL die to complete the 260 case reforming to make the neck-to-sholder junction right so get one, there's no real option on that in my mind.

And, if you also have/get a 7-08 FL die for an intermediate step, you can use it for a "body die" later. Just use the Lee 260 neck sizer to finish sizing. Together, those two dies will help you make the straightest possible 260 cases, which is the first step in getting great concentricity of your loaded rounds.

 

[shegs]

Why bother sizing when Midway supply Remington, Nosler and Norma brass, all for a reasonable price.

 

[MagMan]

Why bother sizing when Midway supply Remington, Nosler and Norma brass, all for a reasonable price.

Because we know Lapua is the best and it makes us feel all warm and fuzzy.