Forming LC match .308 brass to .260 Where do I start?

[USW.260]

Hey, I have a lot of unfired LC-77match brass ".308" and I would like to form some of it into .260. I know I will need to turn the necks once I've formed them but which way should I go to form them...a form-die set, or just by my .260rem seater/sizer and a 7mm08 sizer and step it through? No I haven't google it, No I haven't called RCBS yet....

 

[Fuzzball]

Run it through your 7-08 and .260 sizers with a good but thin coat of lube on the necks.

I doubt you will need to thin the new necks. Check by measuring the diameter of your fired necks and then the finished diameter of a dummy loaded new case; if the loaded neck is the same or smaller than the fired neck you're good to go. You WILL benefit from properly annealing your new necks tho, otherwise they'll split fairly quickly.

 

[sinister]

Not knowing anything about wildcatting, wouldn't it be easier to anneal, then step/neck down thinner-walled commercial brass (like Federal)?

 

[USW.260]

Well this brass has never ben loaded its as new from LC in '77. Its already annealed. I'm mostly worried about the "donut" at the base of the neck. I think one pass through a neck turner will solve that problem if I have it. I will anneal them with in the 2nd or 3rd firing after forming sooner if I have a neck split. Mostly going to be running the lighter wieght bullets out of a Savage 10 Predator Hunter Max-1 rifle. Its going to be for the local Coyotes. I'm thinking of running the 95gr Vmax or the 123Amax, and then something a little heavier this fall for Deer.

 

[kyshootnman]

The donut is usually a problem when necking up. I haven't had the problem, but others have stated having it appear necking 243 up to 260. As you have already said, the only issue with necking 308 down will probably be turning the neck to reduce the thickness.

 

[Fuzzball]

As stated, necking down doesn't make donuts. With that change, your new necks will be about 2 thou thicker than typical, meaning your cartridges will be about 4 thou larger than typical in loaded diameter. It probably won't be enough to matter but check it.

To see if you need to thin, carefully mic a fired case neck and a loaded new one; if your new necks are the same or smaller than fired, you're good to go. If you have to thin, outside turning actually improves the concentricity of the necks while inside reaming only thins what you have.

There's no need to anneal before sizing down but there is afterwards.

 

[turbo54]

Fire a few pieces of actual 260 brass from your rifle.

Measure the diameter of the fired casenecks.

Neck down and seat (.264") bullets into several pieces of the 308 brass.

Measure the diameter of the loaded casenecks.

If the fired casenecks are at least .004" larger than the loaded casenecks, proceed with a smile.

If they are NOT .004" larger, you'll need to neckturn...which sucks....meaning you should sell/store the 308 brass and buy 260 brass.

 

[Fuzzball]

Fuzzball,

Wouldn't inside or outside neck turning depend on the type of sizing die used? Inside ream if using a bushing die and outside turn if using a expander ball?
Thanks.

No, not really. Regardless of the type of sizer used, if one side of the neck is perhaps 2 thou thicker than the other, or if the inside cylinder isn't concentric with the outside, it needs a hand held turner to uniform the thickness AND correct for misalignment of the inner and outter cylinders. A reamer will do neither, it will simply follow the existing hole.

When neck turning, it really is mechanically helpful if the neck's inside diameter snugly matches the turner's pilot; a correct expander ball accomplishes that nicely. That's part of why rather than use any bushing die I much prefer to a body die and a Lee neck die; The Lee die insures minimum brass working and leaves necks as straight as possible.

 

[msiebert]

"If they are NOT .004" larger, you'll need to neckturn"

Which will make them even smaller...you dont add by turning. Yet it's O.K. if they are .004" or larger???? I dont understand that one.

Personally, I have never bought 7mm-08, 260 or 243 brass, ever. I have always necked down Lake City brass to what I need and have not had a problem yet. The 308 brass is shorter in length, but even that has not been a problem for me that I know of. Maybe my Obermeyer barrels will fall apart tonight when I get home??? I have always done it in increments, e.g. 308 to 7mm-08 then to 260. No real reason, I just thought it might be a little easier, but someone else posted on a recent thread about this same thing that he just goes right to the 260 die...I tried it and sure enough it works fine. If the cases have been fired a few times I always anneal them but you have new brass so dont worry about it. Best thing I can tell you is take 20 cases, size them to 260 and shoot the rifle....I am pretty sure if you do that you will come on home and go ahead and size the rest of your cases and move on. One thing I have always noticed about L.C. brass is that the necks seem to be a little inconcentric in thickness which means it's best if you go ahead and outside neck turn them if you want the most accuracy you can get.

One other thing I will add...in 34 years of reloading I have not one single time ever had to inside neck ream a single case ever. In fact, I couldn't even tell you why I might have to and I have done everything imaginable to brass cases including some really strange things to try and get them to shoot better.

 

[turbo54]

"If they are NOT .004" larger, you'll need to neckturn"

Which will make them even smaller...you dont add by turning. Yet it's O.K. if they are .004" or larger???? I dont understand that one.

The method I wrote ensures adequate (~.005") neck clearance with the necked down 308 brass in the .260 chamber.

It is not a difficult concept to understand.

 

[msiebert]

The method I wrote ensures adequate (~.005") neck clearance with the necked down 308 brass in the .260 chamber.

It is not a difficult concept to understand.

After reading it 16 times I get what you are saying...yeah but, who doesn't want to outside neck turn and have the accuracy benefits of concentric necks, not to mention if he's coounting on finding L.C. brass that has good concentric necks on size he's gonna be doin alot more searchin' than shootin'

 

[bunsen27]

Hey, I have a lot of unfired LC-77match brass ".308" and I would like to form some of it into .260. I know I will need to turn the necks once I've formed them but which way should I go to form them...a form-die set, or just by my .260rem seater/sizer and a 7mm08 sizer and step it through? No I haven't google it, No I haven't called RCBS yet....

Honestly, buy Lapua or another .260Rem brand of brass. I've been where you are and although it doesn't sound too difficult to make .260Rem from .308Win it is a pain in the arse. It's your time and your money, but now I just buy Lapua, load and go shoot.

 

[my human host]

I guess I don't see neck turning as that big of a deal. It's like anything else, the more we do it, the faster and better we become. I have to admit tho, I don't shoot matches that cost me brass.

 

[lkessler]

I have done the sizing thing with LC and Fed. brass,it works but is a pain. If you have a 308 use the brass for that,and go ahead and buy yourself some good 260 brass and go from there.

 

[Fuzzball]

I've been reforming surplus .30-06 and 7.62 cases into 7.65 mm, .250 Savage, .243, 6 mm International, .22-250 and a few others for some 35 years. I've seen a couple hundred web posts saying what I'm doing is too hard and/or too much trouble, go buy commercial stuff but for the life of me I can't see why. It isn't difficult, most of us have both the skills and tools to do it, it fills a need and is interesting to do.

If I was happier just going out and buying everything I need to shoot I would get factory ammo and wouldn't be into handloading. ??

 

[Heman]

Agree with Fuzzball. I neck down LC .308 for .260 Rem and LC68 Match for .280 Rem. I will neck turn both. Reason being the stuff is hard and the primer pockets last. The brass is cheap and the consistancy is good. For palma I'm shooting my LC LR brass now and I can't tell a difference in accuracy between it and my Lapua brass, but the pocket book sure can tell a difference.