Has anyone formed 260 Remington cases from 308 Winchester cases? If so please alert to any potential pitfalls to be encountered.
As I see it, it looks like run the case in the full length die and perhaps turn a few necks and I will be there. Any insight is appreciated.

I have formed many of these because there was no factory brass when I first had a 6.5x.308 barreled up. (There's factory brass out there now in case you want the easy way out...)

But, back to your question: No neck turning will be necessary unless you have a very tight chamber. First, make sure you lube the inside of the case neck in addition to the body of the case itself. Then simply run them through the FL die, degrease, chamfer & deburr.....and you're set to begin loading.

So you're saying to put a factory .243 into a .260 chamber and fire it? Not the headspace that I'd be worried about, but the .243 bullet sorta bouncing off the walls of the .264 barrel.

Perhaps I misunderstood? Guy

I've formed cases for my 260 Rem from 243's, 7-08's, and 308's. By far the easiest, no-fuss cases are the 243's. Simply run them through the 260 Rem FL dies and you've got a 260 Rem case.

7-08's work very, very well, too - a close second to the 243. I usually don't use 308's any more for my 260 cases - more times than not, the necks will be just a bit too thick when the finished cartridge is chambered.

The only fly is to keep the reformed cases in clearly marked boxes...otherwise, someone might go thinking the 260 Rem cartridges are actually 243's and try to shoot them in a 243 - with unpleasant results.

For my part, I don't have a 243 - but I don't want someone to think I may be shooting one.

TXLoader

Is there a particular reason you don't want to buy some brand new Remington brass?
I had a 260 barrel built for my target rifle a few months back and decided to take the easy way out and buy 1000 pieces of 260 brass. So far it has been a good choice. Still going thru the new brass cause it takes a long time to fire form 1000 pieces of brass. Even with the virgin brass, the rifle is shooting 1/2 moa on both the 300 and 500 yard group testing using Reloader 22 and Sierra 120 matchkings with Federal match primers.
People have done some bad mouthing of Remington brass, but so far I have been happy with it.

Bruce, that's the most commonsense solution to the "problem." I don't really understand taking on a case forming task, even an easy one, when there is readily available commercial brass. Then again I like to keep my shooting and loading simple.

My .308 cartridges are on .308 brass and go in rifles marked .308 on the barrel. No confusion about whether the brass that is marked .308 is really a 7mm-08 or a 6.5x308 or whatever! Somehow it all just seems simpler that way. Guy

My reasoning for wanting to form these cases from 308 Win is quite simple. I'm a Lapua brass disciple. Lapua also makes 243 Win brass but it is double the cost. I just personally believe by the time I work factory brass and cull out those that are unacceptable I will be doing even more work than forming the cases from the near perfect Lapua brass.

I have the 260 remington and my buddy posted the question on forming brass and had thought about buying remington brass but if i want to shoot long range with it i am looking for more consistent brass. I am going to buy .308 lapua brass as NeMd has some in .338 lapua and is very consistent on weight and neck thickness etc.I also have a .300 win mag and have remington brass. I had 300 pieces brand new and cleaned flash holes sized primer pockets etc and then weighed all the cases and can only come out with 50 pieces that all weigh within a grain of each other. I would like to have a better consistency with the .300 brass but can't find anycompany that makes good brass for it. I am working on tryin to make up loads so i can shoot out to a 1000 yards with it but don't know how good it will be.I also have chronographed all my loads and have seen fluctuations due to difference in case weight so i am looking for more consistent brass for the .260 even if it means forming new brass and a little work. any other suggestions you may have would be appreciated

Okay, I can understand the interest in finding the best brass available. I've seen .308 Win brass necked down in one step to 6.5x308, all it needed afterwards was a bit of neck turning to get it to spec and everything was fine. Mind you, we were doing this before the advent of Remington's .260, but what the heck, Lapua brass has an excellent reputation. Regards, Guy