Home Forums Reloading Varmint Rifles .256 Winchester Magnum

Are any of you loading for this?

I aquired a Winchester 1892 chambered in this cartridge.

I don't mind a reloading adventure and 92's are hard enough to come by, so I thought I'd give it a shot.

Now that I've got it home, I'm having a hard time finding components and consistant information on loads, brass, and bullets.

Apparently the .25/20 doesn't have enough following to demand the local retailers to stock .257 bullets appropriate for a lever rifle. I may have to order them. Do you have preferences? I'm looking at Hornady 60gr FP #2510 and Speer 75gr SPFN//CANN #1237

Is there a source for cast bullets? My usual is Oregon Trail (Laser Cast), but the web site doesn't show anything below .30.

The few places I found that list brass (spendy)show out of stock. As far as making my own ... The opinions seem to range from "easy" to "near impossible".

What are your experiences? Suggestions?

Thanks

Loaded for the 256 many years ago in a Marlin mod.62. Had many of the same problems then as your having now. The Hornady 60gr is a good choice, never tried the Speer bullet, used quite a few of the Rem. 86gr flat points meant for the 25-20 they are still available but hard to find. A quick check shows that both Beartooth cast bullets and Montana Bullet Works offer .257 bullets but in weights that are awfully heavy for the 256. Brass can be made but unless you want to buy an expensive set of forming dies it can be difficult. Not trying to discourage you because the 256 is a fun little cartridge well worth the trouble. Just be patient keep checking the speciality brass sites such as Huntingtons as well as the popular sites. Might go to the Marlin owners site probably more 256 owners there than any where willing to help.

I have the C-H case forming die set and the dies work well. The price was quite reasonable. I bought these several years ago but when I called the fellow at C-H he said they sold several sets of 256WM form dies every year.

The three jacketed bullets mentioned work well in our Marlin Model 62. We can also use the 75-grain spitzer and hollow point bullets.

The Marlin chamber is cut a bit long and large at the base. This is a poor combination makes loading the cartridge to high pressure difficult.

I suggest you use only new 357 Magnum cases for forming.
The problems begin when you try to load the 357 Magnum cases to high pressure for the 256 Win. Mag. The 357 Magnum is rated by SAAMI for 46,000 CUP and the 256 Winchester Magnum is rated at 46,300 CUP with quite a bit of highest-level load data running well in excess of this figure.
When loading re-formed 357 Magnum cases to the highest load levels I seldom get more than four loadings per case.
Reducing load levels to about 75% of maximum gives me virtualy unlimited case life. I am talking about 60-grain loads at 2,700 fps or less using the 357 Magnum case.

For loads which go above the 2,700 fps level I have used cases formed from 357 Maximum brass with good results.

I load the Lyman 257420 65-grain bullet n the 256 Win. Mag. With good results. I generally load these to 1,600 fps and slower. Alliant Unique, 2400, IMR 4227 and Hodgdon Lil� Gun are all good powders for the cartridge with cast bullets.

For accuracy testing single load the Hornady 75-grain V-Max ahead of 12.0 grains of Hodgdon Lil� Gun which gives us 2,170 fps on most days and excellent accuracy - under 1 �� from our rifle at 100-yards - three shot groups.

I have never located any of the 60-grain Hornady JSP bullets but I have hope every time I walk the gun show isles.

Greg Mushial on his web site GMDR, has medium and low velocity data for the 256 Win. Mag. Greg Used a Marlin 1894 to develop his data. Greg�s Marlin shot smaller groups than our Marlin with most loads.

If you are careful, lube well and press the handle slowly, you can form cases with ease by first running them into the SEATER die. Seater dies are cut larger in the neck to allow for the expanded diameter of a round with a bullet, so they make a good intermediate size die for case forming. Be sure to back it out a touch to avoid the crimp shoulder.

If you can't find blunt bullets, shoot it as a two-shot. You may have to finagle the length so they'll feed.

William's advice is excellent.

Strider: A question about your Rifle.
My good friend Jack from Yelm, Washington had a 256 Winchester Magnum built on a Winchester Model 92 action many years ago (20+ years back) I can not remember if it was a Winchester 92 or a Browning 92.
Anyway he had real nice wood put on the Rifle and if I recall correctly he had the metal (receiver/barrel) finished in high gloss.
He used the Rifle as a "two shooter" (one cartridge chambered and one in the magazine) and he Hunted local Coyotes with it for a couple of years before he traded it off.
Does this sound like your Rifle?
Anyway, best of luck with your 256!
Hold into the wind
VarmintGuy

My best guess would be that it was rebuilt in the 60s when the cartridge was still in the public eye. The barrel work feels 1960's to me and the cartridge wasn't around until 61?

It appears to be a custom barrel with a match tight chamber, not a rechambered .25-20. No rear dovetail; it's been tapped for a receiver sight, same as a 94.

They dropped the blade front sight that is normally part of the band and replaced it with a sweat on base type with a dovetail copper bead like you would find on a custom bolt rifle of the period.

Wood is above average by today's standard, but I wouldn't call it fancy. I'm pretty certain it's replacement wood, because the tang was drilled and there is no screw hole in the wood.

Bluing reminds me of the old S&W finish. It would probably rate 98% if it weren't for a bit of light rust around the receiver sight. It has a williams on it now, but you can tell it had a larger receiver sight on it at some point and it rusted underneath it. I'd like to know what that other sight might have been , so I can get another one and hide the rust.

The rifle dates at 1912, so who knows. The receiver locks up tight with a pleasant snap, the action is smooth as can be. It was definately quality work, though I wish it were original. I'd say it's been shot very little.

Nowhere near Yelm, but that doesn't mean anything after 20 years.

Try this: http://www.tennesseevalleybullets.com/products/bullets.html

He has an 85 grain cast lead bullet for $30 per 250.

Strider: Thanks for the reply.
It could be my friends old Rifle - I only saw it a couple of times.
Again best of luck with your nifty Rifle.
I will call my man Jack and see if he can remeber what sights he had on his Rifle.
Hold into the wind
VarmintGuy

Meister makes an 85gr Flatbase cast bullet in 257, I use them for light loads in my 25-204. They are very reasonably priced.






erich

I had a Marlin 62 in 256 Win Mag that work well with the Remington 86 grain 25-20 bullets. I got stung by the 218 Bee and rebarrel the Marlin 62. I never made any brass for the 256 Win Mag, as the rifle came with 1K rounds of white box factory ammo and 300 new Winchester/Olin cases. I've shot about 1/2 box of factory ammo and a couple hundred rounds of reloads with the 86 grain Remington 25-20 bullets.

Standard disclaimer; "YMMV and since my experience is mine alone, your experience is likely to be different.".

Jeff

Well, I finally got an assortment of bullets. Formed 500 pieces of brass. I was so pleased with the way the cartridge looked that I loaded up all 500 rounds. They are really a cool little cartridge.

There is just one minor little problem. They don't chamber.

I can't believe I loaded 500 of those little buggers without running some dummies through the action. I suppose it was because they take so much time to make that I didn't want to waste any.

As I pull 500 hard to find bullets, I'm sure I will remember not to make that mistake again.

It must be close. Trying several, you can force the chamber closed on perhaps one in three. And naturally, it's hard to get them back out again. I see no bullet deformation, lan marks, or scratches on the neck. It appears to be tight around the cartridge body. That's where I see rub marks on the brass.

I'm sure the correct answer is to cast the chamber and take some measurements. I don't have the materials. I'll have to order them.

Any other poor man's fixes?

I'm thinking of reducing the thickness of the shell holder to set the shoulder back a bit.

I'm using RCBS dies.

Maybe try a different brand of dies, before I go with custom made ones?

Interesting puzzle to solve.

I'd pull a couple of bullets and try the cases in your rifle. If they go in OK, them you'll need to seat your bullets deeper. But, if they don't, you'll need to pull all of your bullets and resize the cases to fit your chamber.
If you've crimped your bullets, you probably can't seat them any deeper w/o crushing the cases. E

The bullets won't be wasted, if you pull them carefully. For that quantity, I'd get a collet-style puller. (In fact, when I made a similar mistake and had 1,200 rounds to pull, I even bought one of those little Lee presses as well - just for pulling bullets.)

Pull ten using an inertia puller or whatever you have. Size the cases again with the die as is (but do remove the decap pin!) and try those cases in the gun without bullets. If they chamber, your problem wasn't the size die at all.

Don't overlook the possibility that it was the SEATER die that bulged the cases a bit. If the case mouth hit the crimper, that can happen all too easily. If your trial re-sized cases go in the gun easily, a "seater die bulge" is the first thing I'd suspect.

Certainly a crimp buldge just below the crimp is the first thing to look for. This is hard to see visualy but is pretty easy to measure with a caliper.
Its good advice to pull 2 or 3 bullets and size the cases and then attempt to chamber them.
I assume you are forming your cases from 357 Magnum? I found I had to set the die hard against the shell holder on the first sizing after I formed and trimmed the case. After that if I did not push my loads toward maximum pressure I could size so the die just went to the bottom of the neck on a smoked case.
I have a Marlin and it is very sensitive to case length from rim to the point of the shoulder and base diameter. As I increase pressure and approach maximum loads I run into the problem of Marlin having cut the chamber a bit long from rim to the point of the shoulder and yet the pressure ring on the case still needs to be sized to allow the action to close properly. The chamber dimensions of the Marlin require a balancing act and case life with maximum loads is short when using formed 357 Magnum brass. 357 Maximum increases case life significantly.
If your chamber is a tight one as you suspect you will probably be as lucky as Greg Mushial from GMDR,
.
http://www.gmdr.com/

At the GMDR home page go to the upper right and click on the additional data tab. Greg had a custom chamber cut for his Marlin lever-action rifle and case life in his rifle was much better than mine.

Sounds like good advice.

A straight edge doesn't reveal any bulging. But with the cartridge shape and the annealed brass, I wouldn't be surprised.

I may have over crimped it. I get worried about lever loads pushing back into the case. I've seen factory .30-30s do it enough. Even with the infamous Lee factory crimp.

I may not get to it until this weekend, but I'll be sure and report back what I find.

Thanks

Well ...

An empty case sized hard will chamber with a little effort. It might be good for the brass, but I can't imagine it would be good for the rifle.

An old factory round goes in slick as a whistle.

The cases are dimensionally identical (within .001) length, rim, diameter at shoulder, neck, and base. In all cases, if there is a difference the factory round is the bigger of the two.

One dimension is different - shoulder height. It's visible, probably .05. The factory brass is also a little more round at the curves of shoulder and neck.

I wonder what brand of dies winchester was using for .256 in the 1960s?

Different dies would be a gamble.

I could probably accomplish it by taking a bit at a time off of the die base. Maybe the shell holder.

Anybody ever tried that?

How did you form the cases? The root problem could be there.

Suggestion: Pull one bullet, re-size the case and see if it chambers. If it does not, progressively add shims under the case in the holder and re-size to see if eventually that will produce a case that chambers. If it does, the thickness of shims added will tell you how much to shave from the top of the holder.

If that original re-size (without shims) will chamber, you might try pulling another bullet and merely neck-sizing that case to see if that alone will enable it to chamber. If so, the size issue is with the neck.

Have you checked to see of the cases are too long? Otherwise properly sized case of too much length will give the symptoms you noted.

Someone explained the "bulge" that sometimes is produced by crimper if the case is pushed too far into the seating die. This will certainly cause similar chambering issues. The bulge usually appears right where the case shoulder begins - small end.

Once saw a guy, with a similar problem,insist on using his press/die to re-size the loaded rounds instead of pulling and dumping. I stood way back, and do not recommend such a practice.


Hope this helps.

The shimming was an interesting idea, but you can't get more than a single sheet of paper between case and shell holder.

Length, rim thickness, and diameter at shoulder, base and neck are all the same or .001 smaller than a factory round that chambers fine.

The only thing different is shoulder height and shape. The die is just longer than the chamber.

I guess I'll try thinning the shell holder a few thousandths at a time. It's the cheaper of the parts.

I don't think there is any way a loaded round would fit in a resizing die to shrink the neck on a bottle neck cartridge. You would only crush the neck into the case. I suppose you could custom make one with a larger neck. I wouldn't care to try it.

I have seen a taper crimp applied with a sizing die on long tapered cases like the .38-55. It worked fine, but lends itself to risk if done improperly.

I took a little off the die at a time until a sized piece of brass would just chamber without resistance when the die is screwed tight against the shell holder. A sized piece of brass is now dimensionally identical to an old factory round (shoulder height and measured diameter at base, shoulder and neck). Except it's trimmed length is set to the minimum (1.271). The factory round is at the medium (1.275). Max would be (1.281)

If I had to guess. I'd say this chamber is based off of an unfired factory round. It fits like a glove. It's definately a tight chamber.

How did I make the cases?

Using Starline .357 brass, I annealed the case necks by standing them up in a metal dish pan with just enough water to cover them when tipped on their side. Heat the case mouth with a propane torch untill it just starts to turn red in a dimly lit room and tip the case over into the water with a bamboo skewer.

I polished the inside of the seating die with a tight fitting bore mop and flitz on a drill. Lube the cases well and run them through the polished seating die. Then run them through the sizing die as usual. Trim to length.