.256 Winchester Magnum

[Bigjohn]

I currently have some spare time to do things which I have always wanted to and the other day I was sorting through some barrels when I found one chambered for the .256" Winchester Magnum.

Now, I know a little about this cartridge; both good and bad, but no 'hands on' experience.
A check of the REDDING Catalogue turns up the case forming dies and I could round up a die set for reloading from one or two sources.

I am thinking along the lines of a CB shooter (NO 'J' word bullets) for small game from ambush. Some of the country I live in is ideal for this sort of hunting, basically, locate their areas, trials and feeding grounds then pick a spot and wait.
Their have the advantage if you stalk them, all close range, bushy cover and you need lots of skills with a shotgun.

This barrel is chambered and fitted for a Martini Cadet Action, which I have spare and could be done up quickly for little outlay.

What I need is some practical information on the cartridge, it's loads and idiosyncrasies.
Can you help?

John.

[beagle]

I had a .256 Contender barrel for a while. Shot only cast in it and it was a pretty good shooter out to about 100 yards with Lyman's 257420 70 grain GC bullet.

I kept the dies and I also kept a set of Redding forming dies in hopes that I'll one day rebarrel a M1894 Marlin. The forming dies are pricey.

Cases are easily formed from unplated .357 Magnums. You have to do it in easy steps or you'll get lube wrinkles.

Other that that, nothing strange about it and it's a great little cartridge. Should be good in a martini. Too bad we never got it off the ground here in the US in a decent rifle.

It should be great for what you're intending to use it for./beagle

[JeffinNZ]

Hi John.

Sounds like a great idea. Jim is bound to have a mould suitable and it will make for a very versatile AU hunting round and paper puncher.

Does anyone know how hard/easy it is to reform .357 brass for it?

[Bigjohn]

I have practiced with resizing .357/38 cases to atleast .30". It should be relatively simple to take it the next step to .25.

Redding were still advertising the form die sets in their 2005 Catalogue and I check this morning at the local shop and he can get the Redding brand but it may take some time to get the form die set.

Meantime I can use the Simplex 5/8" neck dies to make up some cases for experiments. There were a couple of sample rounds included with this barrel and I can use them as a guide. I believe that I may have the chamber reamer which was used for this chamber in amongst some equipment I bought from this blokes estate.

John.

[beagle]

The Redding form set is a 2 die set. The first takes it down to about .32 and forms a shoulder. The next sets the shoulder back and sizes a bit farther. Then, I trimmed and FL resized. The key to good cases is keeping lube off that shoulder or wrinkles get real bad.

I ran into a guy at the range several years ago shooting formed nickel plated cases. Now, how he did that, I'm not knowing and he wouldn't tell me as I asked.
The cases looked like heat had been applied as the nickel was discolored around the shoulder area forward. No flaking was evident and I inspected half dozen or so. If anyone knows, I wish they'd post as I'd sure like to know./beagle

[Bigjohn]

I've gauged the twist rate and it comes out at 1 turn in 12". A little tight maybe but I have never used a .256 WM so I don't know for sure.

John

[PPpastordon]

I used to shoot the .256 and a wildcat .30-.357. The .30 was formed by sizing first in the seating die to where it would chamber. Then size in the sizing die. When I got the .256 I used the same process for going from .30 to .256.
The .30 Mauser (7.62X25) or .30 Luger dies can also be used for the intermediate stage forming die - if used carefully. You do not want to set the shoulder back too far. Perhaps there are other fairly common dies that can be used.
I have used just the .256 dies. I would size in stages, just a little at each stage. Fewer cases were lost that way. My friend told me to do it this way and, in his words, give the brass a chance to rest between stages. Golly Gee Whiz - it worked!

[4060MAY]

Beagle
I have a .256 win mag reamer and throater to shoot cast

pm if interested

[felix]

Guns from production runs were 14 twist. ... felix

[Leftoverdj]

Ought to be great for what you have in mind. Doubt I would bother with forming dies with .30 Mauser and .30 Luger being stock items. I made God's plenty of .30 Mauser cases from cutoff .223, and reforming .357 should be easier. I don't see any problem in going down another step to .256 although I would not try anything but anhydrous lanolin for the lube.

That 1-12" twist should stabilize 100 grain bullets. Even it you are not interested in bullets that heavy, you should probably use a longer than spec throat. The guns for which the .256 was chambered limited it to very deeply seated bullets which hurt performance.

I envy you. Cadet actions are scarce and overpriced in the US, or I'd be doing such a project myself.

Beagle, at a guess, he had annealed by dipping in molten lead. Lead won't solder to the nickle and gives a precise heat application that other methods don't.

[Blackwater]

John, I've had and always liked my .256 Contender pistol barrel. FWIW, my experience with forming the cases showed it CAN be done by annealing the case necks before you form them in the std. .256 die, in one step. Losses were many before I annealed the case necks, but after annealing before forming, losses were few, and these were many times used cases, too. Can't say what new brass might do.

If I do any more, I'll get the .30 Mauser dies as recommended above, for an intermediate step, to save BIG on the cost of regulation forming dies. The intermediate step need not be a precise set of specs, just an intermediate step somewhere in the vicinity of the original and the final case dimensions.

If you decide to anneal the .357's before forming, be advised they're VERY short for such doings, and you HAVE to get the water level just right. I experimented with the depth the water needed to be before trying to size many cases. I'd set the water level at a certain height, and try a couple of cases (had plenty but didn't want to waste any) in the sizer, and see how they did. I worked the water level from high to lower, only setting the final depth of imersion by my results on the press with the std. .256 die and a single step forming ram. I even did nickel cases this way, and they've worked perfectly done this way.

The REASON you want to proceed slowly and incrementally with the water depth in annealing is that you do NOT want to soften the case heads, since it's those that keep the pressure contained and the hot gasses away from your face. The Contender isn't as strong a gun as many, and I'd be VERY cautious about softening those case heads from too shallow a depth of the water, if you use the stand 'em up in water and heat the necks method as I usually do.

I also haven't shot this barrel with cast, but I guess I ought to. Ought to make a REAL nice squirrel gun with cast and loads at @ 1500 fps. or so. I'll have to atone for that soon, I guess?