|
Rocky’s Reloading Room |
|
If only… Testing the 256 Winchester Magnum
It’s common for gun writers to praise the products they review. Most articles about cartridges begin and end with assurances that the round is the best thing ever to grace a chamber. Not this time.
Well, not completely, at any rate.
I’ve been a fan of the quarter-bore for years. I am intrigued by the way that .25-caliber guns tend to be very accurate and superbly deadly but light in recoil. And so I had long wanted to see what the almost forgotten 256 Winchester Magnum would do. I firmly believed that the round had disappeared not because of any fault in its own performance but because of a lack of guns chambered in it. The little 25 would shine in a suitable firearm, I thought.
After all, John Wooters (a writer much respected for his honesty) created his delightful 25 Copperhead and found much to praise in it. The Copperhead is simply the 222 Remington necked up. Would not the little rimmed 256 round be almost as effective in a suitable gun as the rimless Copperhead? I believed so.
And so I added the 256 Win Mag to my long list of “gotta try” cartridges. As so often happens, it took years before I got around to doing so. I had long ago determined that the only practical and affordable way to shoot this round would be in a Thompson/Center Contender. After all, the only other kinds of guns ever chambered in the round were the Ruger Hawkeye handgun, the Marlin 62 lever gun and the almost mythical Universal Firearms Ferret semi-auto – all high up on the list of very cash-intensive collector items.
As luck would have it, a very generous owner of a 256 Win Mag Contender barrel offered me his barrel on loan for the purposes of this article. I will not reveal his name here out of respect for his privacy as a gun owner, but I am deeply in debt to his kindness and understanding. Shortly, a very clean 10” bull barrel plus loading dies and formed cases arrived on my doorstep. I also obtained a supply of custom-formed cases to supplement the cases supplied by the owner. And so my eagerly anticipated trials of this little boomer began.
Before I delve into the results of those trials, a little background on the round is in order. For those not familiar with the 256 Winchester Magnum, the cartridge was introduced in 1962 as a joint project of Winchester and Ruger. The first firearm for the round was the unique Ruger Hawkeye “revolver.” I put that description in quotes because the Hawkeye was based on the strong Ruger Blackhawk revolver, but was in fact a single-shot pistol. The cartridge was loaded directly into the barrel, and a massive block (which replaced the normal cylinder) was rotated into battery behind it. The block contained a very long firing pin that transferred the impact of the normal single-action hammer to the primer.
Because the chamber was actually cut in the barrel itself, the nominal 8.5” barrel was reduced to a mere seven inches of swept bore. Ballistics of the factory 60-grain hollowpoint bullet was less than stellar as a result. Neither the gun nor the cartridge lasted long. The Hawkeye was dropped from the Ruger catalog after only a year or two with about 3,300 guns made, and Winchester (the only ammunition provider) discontinued producing ammo about 1990. The lovely Marlin 62 was a sleek little repeater, but it also had a very short production run.
The 256 WM thus would have virtually disappeared from the scene, except for the Contender barrels so chambered in it. There are no exact numbers available, but I’d wager that Thompson Center didn’t wear out many chambering reamers making barrels in 256 WM. Most or all were in the short 10” version -probably to cater to shooters in the handgun metallic silhouette game.
|
|
Making a Case For It
As to the cartridge itself, the 256 Win Mag is simply the standard 357 Magnum handgun round necked down. Case capacity of the reformed case is right at 22 grains of water, full. That capacity puts in right between the older but highly regarded 25-20 (19 grains of water) and Wooters’ Copperhead (28) and far behind the also obsolete 25-35 Winchester (37). Factory ammunition, as mentioned, came in only one loading: a 60-grain jacketed hollowpoint. It was claimed to achieve 2700 fps and 1015 ft-lbs of energy from a 24” barrel. Out to around 200 yards it would pack considerably more power than the 22 Hornet, 218 Bee, or the 25-20. Think of the 256 WM as a 25-20 on steroids, in fact, and you pretty much have the picture. If the round actually achieved those ballistic numbers, it ought to be a great round for called-in predators, I had thought. But “if” is a mighty big word, as we will see.
With barrel, dies and brass in hand, it was almost time to begin shooting. My first obstacle to that end was a temporary shortage of suitable pistol scopes. All my available scopes were mounted on other barrels for other active projects. The only Contender barrels in my safe that saw little use both wore fixed 4X scopes. I’d normally mount a barrel with at least a 7X scope for load testing, but not only were all my high magnification scopes already in use, but their objective bells would reach the muzzle of that dinky 10-inch barrel. I wasn’t willing to risk damaging the objective lenses of any of those scopes with muzzle blast debris, so one of the fixed 4X tubes got the nod.
My second obstacle came in the form of a lack of factory ammo for ballistic baselining. I always fire factory ammo in a test gun before beginning handload trials, if possible. Factory ammo gives me a chance to check for proper feeding, fit and firing. More importantly, it also allows me to set numerical standards for velocity, grouping and case expansion, plus subjective standards for recoil and blast. Fresh factory ammo for the 256 WM is a bit tough to find, however. I found a couple of boxes at a well-stocked gun shop in my own city, but was a bit shocked by the price: $50. A dollar a trigger pull is high living for a handloader; but there was no choice, and I ponied up.
I checked my shelf of reloading manuals and found data for both 60- and 75-grain bullets. Most such data came from older manuals, as newer books seldom list the 256 WM any more. As usual, I began with the heaviest bullet contemplated, and assembled several combinations with the supply of Hornady 75-grain hollowpoints I had in stock. A few of those, plus the factory ammo were taken to my local range for first efforts. I began by getting on target at 100 yards using factory ammo, and was pleased with the low recoil. Muzzle blast was quite pronounced, but not what I’d call fierce with this ammo.
Once on paper, I set up the faithful Oehler 35P and began official work. The tape for the first two five-shot strings showed that factory ammo churned up 2360 fps with a standard deviation of 40. The two groups looked like they spanned about three inches or so through the spotting scope: hardly exciting, but not too bad considering the four-power scope.
My first groups with reloads made me smile. The book-recommended charge of sixteen grains of IMR 4227 under the 75 HP clocked 2335 with a SD of 20 and another 3” group average. As it turned out, that would be the about the standard group average I’d get with any bullet. At this first session, I’d gotten results that were a match for factory ammo, yet used a heavier bullet. So far so good, I thought.
Back at the bench, I learned that factory ammo expanded cases to 0.3773” just above the web. That became my limit for reloads as well. The book load that matched factory ammo in velocity also matched it in expansion, which served as a confirmation.
Right here is where my third small obstacle raised its head. I had used some of the custom-formed cases (the supplier is no longer in business) when I loaded my first batch of test loads. When I sized those cases for the second round of tests, I was shocked to find that bullets simply fell into the sized cases! Suspecting some problem with the custom brass, I took a few standard 357 magnum cases, lubed them with Imperial Sizing Die Wax and gingerly ran them into the sizer. One neck crumpled, but two others formed into 256 WM cases with no seeming problem. Again, however, bullets just fell through the necks.
Scratching my head, I turned to the small supply of cases sent to me by the barrel’s owner. Surprise: these cases sized and held bullets normally. Now totally confused, I made a quick call to the Customer Service folks at RCBS. There, John Hallmark enlightened me. Original RCBS dies for the 256 Win Mag were cut to work with early 357 Magnum brass, which apparently had thicker brass in their necks than the current cases. Those dies may not size modern brass enough to hold a bullet. He asked me to send him the dies I had, plus some fired cases for examination. Sure enough, after a week or so, John called me and confirmed that the dies I had were a bit large in the neck. He graciously custom-cut a new set of dies for me based on the fired cases I had sent him. Even though he expedited the work, however, the new dies did not arrive until my local shooting range had closed for the winter.
With four months at hand before I could resume shooting, I had plenty of time to cogitate a bit and plan the rest of the shooting tests. I first made a supply of reformed cases from new 357 Magnum brass. Following an old but almost unknown trick, I first polished the inside of the seater die with Flitz metal polish. Lubing cases with Imperial wax and running them through the seater die produced cases of almost fully formed dimensions and with no losses. After examining them for cracks or defects (there were none), I then re-lubed and ran them through the RCBS sizer. Again, there were no losses, and 100 ready-to-load 256 Magnum cases were the result.
Having already established that I could match factory ballistics, I now endeavored to try some powders that hadn’t been around when the manuals were written. I ran the 256 WM through my copy of Load From A Disk software, and found that about the slowest powder that might be useful in the case was in the neighborhood of 4198 in burn rate. Several powders introduced in the last few years are just a bit faster or not much slower than 4198, including 1680 and XMR2015 from Accurate Arms, LilGun and Benchmark from Hodgdon, and Xterminator from RamShot. I also included good old Alliant Reloder-7 as a possible useful powder, and set about guesstimating charge levels.
By being cautious and methodical, I was able to work up to maximum loads with all these powders. Some loads reached maximum by virtue of filling the case, and some by virtue of near-factory case expansion. Those that filled the case proved to be too slow, delivering lower than usual velocities and minimal case expansion. First to be eliminated on that score were Xterminator and Benchmark, which delivered only 1800 fps and/or poor accuracy.
Accurate 2015 and Alliant RL-7, on the other hand, did very well indeed. Both turned in speeds of 2100 fps and groups in the 1.5 to 2” range. That’s well under factory speeds, granted. But this bullet was also 20% heavier than the factory bullet. These two powders were accurate and pleasant to shoot with low blast. The best RL-7 load put four of those 75 HPs into 0.85” for example with one just a bit out for a five-shot group of 1.2”. That’s about as good as I can hold with a 4X pistol scope. Case expansion was only 0.3768 with that load, too.
With powders faster than 4227, results were pretty good, also. I found one recommended load using Alliant 2400 powder in this bullet weight, and tried it as printed. A charge of 13.5 grains delivered 2122 fps and an SD of only 10, and groups right at 3”. Case expansion was just under factory levels. Back when it was first developed, 2400 was considered a rifle powder. First lots of this powder gave 2400 fps in the fledgling 22 Hornet, and that’s how the powder got its name. Even though more tons of 2400 have probably been burned in magnum handguns than rifles, I have found that it is still a great rifle powder in certain limited applications involving small cases or in cast bullet loads in larger cases.
I was very curious to see what Accurate 1680 and Hodgdon LilGun powders would do. Usually, 1680 burns faster than LilGun, but in this cartridge that is apparently reversed. With 1680, I worked up to 16.5 grains and may have been able to get to 17.0. But I stopped when I reached nearly full case expansion. At that level, I had 2100 fps and four shots into 1.1” plus a called flyer. This also is a good load combination. LilGun peaked out with only 15.0 grains, but delivered the highest velocity of any powder with this bullet – a very common happening with LilGun! Speed was 2397 and SD15 at maximum case expansion, but groups were 3.5” or so. Perhaps a bit of tweaking bullet depth or a bit lower charge might improve that, and if so, this would be the supreme powder with the 75-grain bullet weight.
By the way, I re-fired some of the better loads using the Hornady 75 Vmax bullet and got essentially duplicate results. The Vmax is known for its reliable and positive expansion at even low speeds, and has better ballistic numbers to boot. If I used the 256 Win Mag as a predator cartridge, this is probably the bullet I’d select.
Having wrung out the 75-grain bullets, I moved now to the bullet that was created especially for the 25-20 and other small-cased quarter bores, the 60-grain Hornady flat-nosed softpoint. The flat nose is there to be used in lever-action rifles, and it does lower the ballistic coefficient of the bullet substantially. But these aren’t long-range rounds, so the true difference is moot. This bullet weight would give me a chance to truly measure performance against the identical factory bullet weight.
With the 60-grainers, I began using the charges that proved maximum with 75-grain bullets as start loads. That’s precisely why I always begin development with the heaviest bullet I’ll use in a given cartridge. I also tried a larger number of book loads in this bullet weight, as more of them are published. In addition to the traditional powders such as 4227, I also used the newer powders that proved useful before, as well as a few even faster ones. In addition to the 1680, 2015, RL-7, LilGun and 2400 used before, I also tested Alliant Blue Dot, Accurate AA-9 and WW 296.
Again, the traditional powders worked very well indeed. IMR 4227 gave 2529 fps and groups in the two-inch range with a 16.5-grain charge. That is half a grain over the book maximum as listed by Hornady, but a bit under some other loads I’d found published. Alliant 2400 again turned in great results as well. Fifteen grains gave 2450 fps with an SD of just seven! Groups ran just about three inches but centered very low.
I might say here that large changes in point of impact were the rule with this cartridge, even within a single bullet weight, but dramatically so when changing bullet weights. That off-target low group with 2400 powder was the first group fired in the 60-grain bullet weight, and it hit over a foot lower than the last group made with the 75 Vmax. If one hunted with this round, he’d best sight in and stick with one bullet and one load or risk a lot of misses.
Accurate 2015 delivered 2260 fps with the lighter bullet, with groups of 2.5 inches. With a half grain less, however, it gave 2200 fps and a best group of only 0.8”. The gun simply did not like the pairing of Reloder-7 and the 60 FP bullet, though. Velocity was a mere 2170 fps with miserable four-inch-plus groups.
The faster pistol powders gave mixed results, too. Blue Dot managed to deliver 2350 fps and groups again about three inches, with very mild blast. Blast was so mild that I had to look twice at the chronograph printout, in fact. I couldn’t believe that a load with such a mild report was really going that fast! Accurate AA-9 proved to be a poor choice, with very low speeds of 1800 fps and large groups, but 16.0 of WW296 raised my eyebrows with a whopping 2525 fps and 2.5” group average. Perhaps I shouldn’t have been surprised, as WW296 is an outstanding powder in the 256’s parent case of 357 Magnum.
I saved loads with AA-1680 and LilGun for last, hoping to have my bell rung once again. The 1680 loads only managed to churn up 2300 fps with groups in the two-inch range, however. The bell bonged with LilGun. Sixteen grains pushed the little 60-grain pill across the Oehler at 2597 fps! The SD was a bit high at 43, and groups ran about three inches again. But as with the 75 grainers, I believe that a little tweaking of bullet depth or primer type might draw those groups in.
With two bullet weights then, I had found loads that tie or better the 2300 fps factory velocity at equal or better accuracy. With both bullets, the new Hodgdon LilGun proved the velocity champ. With 75-grain bullets, LilGun managed 2397 fps and with the 60-grain it hit 2597 with less than factory case expansion in both instances. Call it 2400 and 2600 fps, respectively. Assuming I can tweak the accuracy, those are very respectable numbers indeed from such a small case.
Next-best loads, though slower, were quite accurate. Traditional IMR 4227 under the 75s gave 2300 fps and very usable groups with mild blast: a very acceptable combination. With the 60-grain pill, WW296 gave a surprising 2500+ speed. Or, with either bullet, one could use Alliant 2400 with perfectly acceptable results. All in all, the 256 WM turned in a fairly good performance. So why did I pen the almost deprecating language at the start of this article?
A few factors combine to bring about my rather captious review of the 256 WM. First, the fact that neither guns nor factory ammo are still made is one strike against it. Even Contender barrels in 256 WM are a special-order item from Fox Ridge, the T/C Custom House or from custom barrel makers. Second, the round is essentially a handload-only proposition now that factory ammo has been discontinued for over a decade. Third, I simply did not achieve the accuracy results that I’d hoped for. Factory barrels are sometimes reputed to have overly-long chamber throats, which can lead to poor accuracy. But this barrel was made by the craftsmen at Bullberry Barrel Works. I can see no fault with it whatever. The muzzle crown is perfect, and the throat area looks clean and sharp. The fact is there, however, that three-inch groups were the norm with most loads. If that truly represents the inherent accuracy level of the cartridge rather than this individual barrel, I cannot in good conscience make a recommendation that varminters or predator hunters try the round.
If this barrel were mine, I’d make a chamber cast to see just where the throat leade lies. I’d truly like to re-run this whole test with a carbine-length barrel by Bullberry. I honestly think the little 256 WM would perk right up and sparkle from a well-made barrel of 18-21” length. In such a gun, it might excel as a lightweight walking varminter, or a called-in predator rifle. Like the old 25-20, I think it would also shine on small edible game with cast bullets. I’d sure like to find out.
But when I return this barrel and dies to their owner, I am pretty sure that I’ll have fired my last round of 256 Winchester Magnum. That’s a shame, really. I still like the concept of this potent little package, even though the “magnum” sobriquet has no business whatever in its name. And what I’ll do with most of a $50 box of ammunition on my shelf, I have no idea. Maybe if I stare at that box long enough, I might even be able to justify a call to a barrel maker. Come to think of it, I do have a spare rifle scope…
Rocky Raab
Load From a Disk software W Square Enterprises 9826 Sagedale Dr Houston TX 77089 www.loadammo.com
Bullberry Barrel Works 2430 West Bullberry Lane Hurricane UT 84737 www.bullberry.com |
|
Rocky found that Hodgdon Lil Gun is THE powder for the .256 Win Mag with either 60- or 75-grain bullets. He used Winchester primers and reformed cases for all loads. See text for loads tested. |
|
Custom form dies are available, but you can simply use the seater die as a form die instead. No cases were lost using this method. |