Have any of you actually formed .260 brass from .243 brass? Any special technique or dies used? I have a "ton" of .243 brass, mostly new and mostly nickel plated. Will soon have a .260 Kimber "Montana" and would like to use my .243 brass if it will work.

Yeah Lone Bull I have done quite a bit of it. I prefer necking down 308 and 708 brass.

However, depending on what die series you use, if you use RCBS just call their customer service number ( 800-533-5000) and tell them what you are doing. They will send you a neck expander to fit your 260 die that will allow you to do so without a lot of trouble.

If your 243 brass has been shot, but not resized back to 243, that makes the process even simplier.

You and the cartridge will become friends. I dont' know if you are planning to varmint shoot with it, or target shoot. If you target shoot, I highly recommend the Sierra 107 grain match bullets. Although they can be pushed to 3300 fps, their accuracy is best at 2800 to 3000 fps. They are very flat shooting and produce less recoil than the 120s and the 140s.

I have used them in competiton with excellent results to 600 yds.

Cheers and Good shooting
Seafire

PS, welcome to the 6.5 club.

Thank you for the great post, Seafire. I will take your recommendation. I do not intend to use my .260 for varmints, just target shooting and hunting. I need a light kicking rifle for girlfriends [one at a time of course -- I seem to change them on a regular basis] to use for deer, antelope, and elk. The .243 was a bit light for elk although it did an outstanding job on a black bear.

This is not quite my first 6.5 caliber. I brought a nice JP Sauer drilling back from Germany and the rifle barrel was chambered in 6.5x57 Rimmed. I sold it 20+ years ago. I wanted a 6.5 ever since and finally have done it. Within the past few years, "monster mashers" are no longer interesting, and I have slowly purged my arsenal of them. I may use that .260 myself!

How about nickel-plated brass? It seems harder than regular brass.

I did it just to see if it would work. No special trick....just ran .243 Win brass thru my .260 FL sizing die and presto....260 brass. Quite sure you could do it the other way as well.

It may not really be worth the bother to neck 243 brass up. Some downside points to it is that it increases the chance of a mix up of ammo. The 260 looks like a 243 as it is and the necks can't be as good as orginal cases.

You are getting an expensive precision rifle. Just spend twenty bucks on some new 260 brass and do it right.

Seafire,

You have become my .260 "GURU." Hope you do not mind another question. I have many rounds of loaded .243 ammunition. Do you think it would be safe to fire them in my .260 Rem.? Would that fireform the brass to .260 Rem.?

Best regards,

Larry
AKA Lone Bull

What do you other guys think??? Has anyone tried it?

Don't do it.

Larry,

You will find that will give a fair amount of throat erosion to the barrel, which I am sure you want to avoid. In those instances, I would disassemble the rounds. I use an RCBS tool that looks like a hammer. The round is put inside and it separates them by hitting the hammer on a board. I am sure it has a name but that escapes me at the moment.

I just disassembled 300 rounds of 223 loaded last year with Benchmark, and about 100 of 22/250 rounds, that had H 380 in them. I am going to use those bullets in the 22/250 that were in the 223 cases. I am going to use the Benchmark in my 260 Rem instead, and the H 380 is my prime powder for 223's with a 75 grain and 80 grain Match bullets.

Just my desires change, but it is not a big deal to disassemble rounds like that for me. Especially if it is left over from the previous season.

Yeah the brass would fire form, but as I say, I would not want the throat erosion especially on a new Nice rifle like that.

I plan on giving you a call to check that 260 out when I pass thru Montana in June or so. I have a high school graduation to attend in Minnesota and in Billings in June.

Cheers and Good shooting
seafire

Thanks guys -- I thought you all might say that. I just needed your confirmation that it was not a good idea. I will pull everything using my RCBS Collet type bullet puller. I gave up on the inertia [hammer] types and have great results with the collet style. It is fast, and [surprisingly] does not mar the bullets.

I would agree with Savage somewhat. My solution to the possibility of ammo fired in the wrong rifle, when I re-formed a bunch of .243 brass into 7-08, was to do away with any .243's(1) I owned. They make wonderful platforms to rebarrel into something useful.
One thing I did when opening up the .243's into 7-08's was to remove the resizing ball and stem from the die, chuck it into a drill motor, and hone a bit more taper to the nose of the ball. I also lubed the inside of the neck. I don't know if this would be needed in this case as your "jump" in calibre is smaller.

Good thought, Beemanbeme -- and that is my intent. I have two .243s for sale and more .243 bullets than some gun shops! There is a gun show soon in Helena and I have reserved a table to "move it all." I also have a lot of other gun "stuff" I no longer "love" or need. This gets to be an expensive hobby -- but oh what fun I have!

Sometimes it takes a while for something to sink in with us old set-in-their-ways shooters. I just ordered 500 new Remington brand .260 Remington brass. I doubt I will ever use that much, but the price was right and I can pass it on if anyone is interested in, say, 200 rounds. I found it not difficult to move my old .243 brass, new and 1X fired.

Larry,

Got have email!
seafire

I agree it's pretty questionable about being worth the effort to neck them up, but the concern about them being head stamped wrong and getting in the wrong gun is unjustified. Ever try and get a .260 Rem in a .243? Ain't going to happen. Even a .25 on a .243 case won't go in a .243, so there is no danger.