It was a rainy day yesterday and I looked for a loading project. I won a .308 browning lightning BLR recently and didn't have much brass to load for it. I was looking over my inventory of new cases and saw a bunch of new .243's sitting there and a little light went on in my head. I greased the inside of the neck with imperial wax and ran them over a hornady (love those eliptical spindles) 7mm die and then full sized them in my hornady .308 die. It took a little effort to run the case mouths over the expanders but they came out nice. Tried 'em in the gun and they fit like a glove. Ran them accross my rcbs casemaster and had excellent runnout to. Checking the case necks it looks like they thinned down .001" with the "stretch."

NOt being good enough to let well enough alone I thought I'd try the same procedure with fired brass that had been out of a .243. The first thing I noticed was it took alot more effort to get them over the expander ball. (They had been fired 2x's) Then I noticed going into the full length die it took alot to size the main body down. When I went to chamber them they wouldn't chamber. I tried screwing the die down a little tighter but it didn't change the fit and checking the headspace I found that even moving the die down didn't change that.
FWIW I guess what I learned is if you are going to try and make something out of another caliber your odds of succeeding are alot better if you start with new brass. The brass seems alot more "shapeable" and starting with good dimension's instead of something that had been out of another chamber is the way to start. Just thought I'd pass this along.

The 2x stuff was work hardened, the new stuff was still showing the effects of the factories annealing process. If your having to reform with used brass, it's often better if you anneal it (neck/shoulder area only) first.

As I am new to reloading, there are many things that I have to figure out. I was reading this post and was wondering why do this to the 243 brass? Does it produce a differently shaped case, besides the neck diameter? Thanks and sorry for the "stupid" question

Kraky - Interesting post. I've reformed a lot of cases in my life but obviously been too dense to realize NEW brass makes the process easier. And perhaps this is due to the fact that I seldom started with new brass to begin with.

I've also learned that the more powerful your press, the easier it is on both you AND THE BRASS. My favorite was the old RCBS A-2 press.
Talk about power! I was a fool to ever sell it.

Hunter333 - Brass is an extremely maleable metal and it will amaze you what can be done to shape and reshape it. My wildest creations were converting 30/06 brass into .308 X 1.5" ...although I finally settled on 300 Savage brass as the best for this project.

Anyway, with good brass, good smooth dies and a powerful press you can do some wild things to cartridges. Properly done it is completely safe.

Pecos, thanks for the info. Why would one want to change the shape of the brass? Does it make the neck longer and the body fatter? Does it allow for more powder increases? Thanks again.

Hello Hunter333,

The length to shoulder, body taper and size, etc. is all identical for 243 and 308 Wins, the only difference is the neck/bullet dias. I am not sure why the twice-fired 243 brass wouldn't chamber after full length resize, it should have.

I recently sized 243 and 308 (both new Lapua) to 260 Rem. Surprisingly to me, the 308 was easier, even though it had to "go farther". The 243 started easier, but required a lot more force at the neck/taper point. Finished neck dias were .291" with 243 brass, and .295" with the 308 brass.

Regards, Bill

Does this mean that one could load and shoot different rounds from a 30-06 after changing the neck size? I think that this is something I need pictures to understand, sorry for my ignorance....

Hunter333,

I am not sure that I understand your last question. You can take a fired 30-06 case and neck it up to 338-06 or 35 whelen, or neck it down to 270 win or 25-06. However, those rounds should only be fired in guns chambered for those cartridges. You can not take a 30-06, neck it up to 35 Whelen, and fire it in a 30-06 chambered rifle!

There are "families" of cartridges, based on a "parent" case. "Offspring" of the 30-06 case are 6.5-06, 25-06, 270Win, 280 Rem, 338-06 and 35 Whelen, plus "wildcats". "Offspring" of the 308 Win include the 243Win, 260Rem, 7-08Rem, 358Win and some other "wildcats". Many of the Weatherby magnums and the 8mmRemMag use the full length 375H&H/300H&H magnum case as a parent (I forget which H&H was first, but think it was 375). The 458WinMag is based on a shortened H&H case, and its' "offspring" include the 338WinMag, 300WinMag and 7mmRemMag. There are many more that I am forgetting (or just not putting down), but I hope you get the idea, in fact there are enough to fill a book(s)! I highly recommend "Cartridges of the World" to you.

Edited to add: The bullet must match the bore diameter. The 30-06 Sprigfield, 308 Winchester, and 300 H&H magnum, for example, have a bore diameter of 0.308" and shoot bullets with 0.308" diameter. To "make" a 243 Winchester, you would take a 308 Winchester "parent" case, "neck it down" for 0.243" bullet diameter, and shoot it in a gun with a 0.243" bore.

Hope this helps, Bill

[ 10-22-2002, 01:29: Message edited by: Bill M ]

Bill, thanks for the info!! I am going to get that book, this seems pretty interesting. I am loading some rounds for my buddies 270 and am going to reread this when I have casings in front of me.....

Hunter333,

You are welcome. Compare that 270Win case to a 30-06 Springfield case, and you will see that the only real difference is the neck/bullet diameter, .277 vs .308 inches.

Cartridges of the World is available at a number of places and I think is a valuable reference. Lots of good, interesting information.

Regards, Bill

Check those necks if you try this at home. Sizing a case down often thickens a neck and it must be reamed or turned before it is safe to use.

The reasons for reforming cases are cost and availablity. If you are sitting on a few thousand .308 cases you got for little or nothing, you are not likely to want to pay new brass prices for 7mm-08 or .358.

If, like me, you have a weakness for the truly strange, you have to reform brass.