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.25 Winchester Super Short Magnum (WSSM)


In 2004 Winchester announced the introduction of a third cartridge to be added to their Super Short Magnum line, the .25 WSSM. Two years later, the entire line of WSSM rifle production was discontinued, disappearing into obscurity.
To understand how such matters came about, it is necessary to study the history of the Winchester brand. The following information and time line is very much over-simplified but is presented to give the reader a practical insight into the factors which have influenced Winchester rifle production.
In 1866, Oliver Winchester purchased the New Haven Arms company and re-named it the Winchester Repeating Arms company (prior to this, Oliver was a major stock holder). In 1931, the Winchester Repeating Arms company was sold to Olin Corporation. Olin owned the Western Cartridge company and through buying the Winchester brand name and plant, was able to combine the two divisions under the one ‘Winchester’ banner.
In 1981, due to financial strain, Olin sold the Winchester New Haven plant to its Employees. The Employees formed their own company called the U.S Repeating Arms Company (USRAC). Olin retained their ammunition manufacturing division along with the Trademark name ‘Winchester’. Olin then leased the rights to use this name to USRAC. For the next few years USRAC produced Winchester rifles however financial strife continued to take its toll. 
In 1989, the fully bankrupt USRAC was taken over by FN Herstal of Belgium. FN took over both the New Haven plant as well as the rights to the Winchester name - still leased from Olin. FN Herstal, its head quarters based in Belgium, has two divisions, the manufacture of Defense / Law Enforcement weapons and its sporting arms division. Of major interest is the fact that U.S gun designer John Moses Browning worked very closely with FN from 1897 onwards. FN eventually bought the rights to Browning’s military and sporting arms designs and while FN retained its own ‘FN’ branding for military rifles, the sporting division was renamed Browning. 
When FN Herstal purchased Winchester, it was adopted by the Browning division of this huge corporation. The Winchester saga had now almost, in a way, come full circle considering that John Moses Browning also worked with and designed arms for Oliver Winchester.
Regardless of this buy out, FN were unable to boost Winchester rifle sales for a worthwhile return. The short magnums were the most recent attempt to revive sales. Finally, in 2006, FN (using the name Winchester) announced the closure of the New Haven plant and the discontinuation of rifle production.  This meant an end to the production of the traditional lever action M94 rifle and the end of the famous Model 70 in all calibers including the WSM’s and WSSM’s.
In 2008, FN was able to revive limited production of ‘Winchester’ brand rifles by utilizing their military manufacturing plant located in Columbia, South Carolina. This plant is now producing the M70 once again along with 70% of all U.S infantry hardware.
As for the WSSM’s, Olin still manufacture ammunition but neither the Browning division of FN or its Winchester subsidiary division are willing to produce rifles in these calibers.
Looking back at the 2006 catalogs, between the Browning and Winchester divisions, the WSSM’s were available in twelve models. Combining the variations in caliber of .223, .243 and .25 with the variations in rifle style, this was a total of thirty six different options - surely a case of over diversification and over investment. What ever the case, the .25WSSM and its scaled down M70 action was perhaps the greatest youth combination ever invented, gone before hunters really had a chance to use it and become familiar with its strengths.
At this time of writing, the only thing keeping the WSSM’s alive is the ammunition produced by Olin. No manufacturer produces WSSM rifles and although custom gun makers are able to build WSSM’s, these rifles do not have the fully scaled down actions that are so well suited to young people. Perhaps the saddest aspect of the WSSM debacle is that most - nearly all of these rifles - were bought by adult hunters. The WSSM rifles were certainly marketed towards adult hunters and of the thirty six variations of 2006, none had scaled down stocks ideal for youngsters. Without question, the WSSM family was completely under utilized. 
There is currently a small group of hunters, mostly in the U.S, who own and shoot the WSSM’s and are thoroughly pleased with the results. The .25 WSSM is a definite favorite amongst the WSSM fans but is also the hardest to come by combination. 


The .25 WSSM is a true mini powerhouse. As previously stated, this cartridge is ideal for youths in a most unique manner. Unlike the other WSSM’s, the .25 can be loaded with 87 grain bullets at the beginning, working up to hard hitting 120 grain bullets as the young shooter gains confidence. This is a cartridge that can easily be adapted to suit hunters of 11 to 12 years of age yet serve them well into their late teens or for their full hunting career if that is what suits. The .25 can be downloaded or fully loaded to sizzling velocities, all from a 22” barrel.
Realistically, one has to see the performance of the .25’s on game to understand just how effective and efficient these cartridges are. That said, velocity is the ally of the .25’s and as ranges are extended, speed of killing is reduced. With either factory ammunition or hand loads, a good rule of thumb is that when driving any .257” fast expanding bullet at 3200fps, expect fast kills out to 200 yards on medium game and slightly delayed kills thereafter. Slower muzzle velocities will decrease this range, higher velocities will extend it.  This is a simple and true base line, especially helpful when building youth loads.
There is not a great deal of difference between the .25-06 and .25WSSM. Hand loaders can use the long actions of their .25-06 rifles to obtain greater flexibility over seating depths and COAL’s in comparison to the short magazine space available in the true super short actions. This leads to even further versatility in powder choice.
The .25-06 has between 80 and 100fps in its favor but to do so it must be chambered in a long action with a 24” barrel, ideal for adults but not for the very young. Is the extra 100fps of the .25-06 worth it - yes if hunting steep country where slow kills will allow game to run and then fall from steep bluffs into in-accessible ravines, it pays to use every fps available. The .25-06 has between 50 and 100 yards advantage in fast killing over the .25 WSSM. Again, these statements are only relevant to a single aspect of performance and do not take into account the usefulness of the .25 WSSM to youths. The .25 WSSM kills medium game in a clean manner out to and beyond 300 yards. 
The question of how big an animal will the .25’s handle seems to crop up continuously. The .25’s are ideal for light to mid (normal) sized deer species. The main advantage of larger calibers on heavier animals such as Elk, is the ability to produce faster killing through broader and deeper wounds, especially at extended ranges.

Factory Ammunition

Current Factory Loads from Winchester Olin include the 85 grain Nosler / Combined Technologies Ballistic Silver Tip at 3470fps, the 115 grain Ballistic Silver Tip at 3060fps, the 110 grain Nosler Accubond at 3100fps and for those on a more limited budget, the 120 grain Positive Expanding Point (PEP) soft point at 2990fps. These velocities are taken from a 24” test barrel while the actual rifles in this caliber typically have 22” barrels. Browning also produced a series of rifles with 21” barrels. Velocity per inch of barrel removed is the usual 35fps common with small bores. That said, some rifles do produce the factory stated velocities, the results depending on individual barrel and chamber tolerances.
Of the above loads, the 85 grain BST is better suited to varminting than medium game, however this bullet is effective on game up to 60kg (132lb). The 115 grain BST is a good all-rounder for lighter medium game but on heavier animals, comes into its own at ranges beyond 200 yards. Performance of this load is very consistent producing vivid expansion and adequate penetration on deer sized game with cross body and quartering shots. The 120 grain soft point is a good all-round projectile for hunters on a budget. This is a very soft bullet, has a little more controlled expansion than the BST but not enough to make any real gains in penetration. The soft point opens up just as quickly as the BST but does not hold its velocity quite so well at range (regarding hydrostatic shock) and is also effected by wind drift a touch more than the BST.
The 110 grain Nosler Accubond is definitely the pick of factory loads. This is a very expensive load but cancels out the need for any other loading in the .25 WSSM. Whether hunting varmints or medium game, this is an all-round bullet capable of handling animals up to the size of Red and Mule Deer with cross body or quartering shots.
Unfortunately there is no factory load specifically suited to hunting Elk sized game. The Nosler Accubond is capable of taking large animals of this size in cool hands, the key is practice, not at targets but on lighter game animals in order to best understand shot placement versus game reaction - both inside and outside of 200 yards.

Hand Loading

The .25 WSSM produces best all-round results when loaded with powders in the 4350 range. Spherical W760 and H414 are also extremely good for achieving high velocities. For those focused on varminting, Hodgdon Varget (ADI2208) produces the highest potential velocities with 75 to 87 grain bullets. All of the WSSM’s reach peak pressure very quickly therefore it is imperative that hand loaders work up loads a half grain at a time rather than full grain increments.
Realistic safe working velocities from 22” barrels include 3550fps with 75 grain bullets, 3450fps with 85 to 87 grain bullets, 3250fps with 100 grain bullets, 3030fps with the 110 grain Accubond, 2980fps with 115 to 117 grain bullets and 2920fps with 120 grain bullets. Please note, these are averages and some rifles have achieved much higher velocities. The .25 WSSM is very pressure sensitive to changes in powder type and projectile form so for top velocities, experimentation is a necessity. Also note that as bullet weight is increased above 100 grains, velocity drops dramatically due to the cramping of powder space. 
Another factor affecting the WSSM hand loader is the issue of brass neck thickness and therefore its malleability. The WSSM brass produced by Olin is known for being overly thick in the shoulder/neck area. This leads to cracking at the shoulder and neck due to work hardening and cases should always be annealed to prevent this occurrence. Also, should cracks occur, it is vital to clean the throat of the rifle chamber with an over sized bronze bristle brush to remove case compacted powder fouling which has the potential to both lift pressure and ruin accuracy.
The subject of projectile performance in the .25’s has been discussed in great detail in the .25-06 and as these two cartridges are very similar in performance, readers are directed to that text for further information. A couple of points can however be reiterated. Without a doubt the 100 grain bullet weight, particularly the Sierra Game King is the most spectacular medium game killer in the hot .25’s.  Nevertheless, while the heavier slower loads do not produce such a dramatic effect, they are the more consistent, clean killers over a broad range of game animals and hunting conditions. In this regard, the best of the best has to be the 120 grain Nosler Partition. This projectile is relatively inexpensive, extremely fast expanding and gives adequate penetration. This is the go to bullet for all hunting of game weighing between 80 and 200kg (180 to 400lb). For larger game, the Barnes X bullets are a must.

Closing Comments

It’s a sad story, the introduction and nearly immediate withdrawal of the WSSM chamberings. While the hunting world can certainly survive without the .223 and .243 WSSM’s, the .25 WSSM has (or had) some truly great advantages as a youth cartridge and rifle combination. For some reason, the design and marketing of the .25 WSSM was, in my opinion, badly off course. The Winchester M70 rifle could have been built with not only a scaled down action but also a scaled down stock suitable for the young, perhaps with recoil pad spacers for later on.
Hunters need to be aware that while it is very uncomfortable to shoot a rifle with too long a stock, the adult hunter can get behind a low recoiling rifle of youth stock dimensions and shoot both comfortably and well.  The miniature M70 could have been both a correctly fitted youth rifle and an extremely portable carbine for adults. It did not need a dozen variations in action or stock style, just a simple functional rig built with a clear purpose in mind.
Many hunters have wondered, why did the .25 WSSM designers not opt for a .25 WSM based on the .270 WSM case? Unfortunately, the wildcat .25 WSM is an incredibly pressure sensitive cartridge showing severe pressure problems with not only warm loads but also starting loads. For the skilled hand loader, the .25 WSM is an outstanding performer but for the novice, hand loading a .25 WSM poses many risks.
Suggested loads: .25 WSSM Barrel length: 22”
No ID   Sectional Density Ballistic Coefficient Observed  MV Fps ME
1 FL Win 110gr Accubond .238 .418 3030 2242
2 FL Win 115gr BST .249 .453 2990 2283
3 FL Win 120gr PEP .260 .344 2920 2272
Suggested sight settings and bullet paths           
1 Yards 100 150 273 310 350 375 400  
  Bt. path +3 +3.6 0 -3 -6.6 -9.5 -12.9  
2 Yards 100 150 270 310 350 375 400  
  Bt. path +3 +3.6 0 -3 -6.7 -9.9 -13.3  
3 Yards 100 150 255 290 325 350 375 400
  Bt. path +3 +3.5 0 -3 -6.3 -9.4 -13 -17.2
No At yards 10mphXwind Velocity Ft-lb’s
1 300 6.3 2414 1423
2 300 6 2413 1486
3 300 8.3 2196 1285
 25 wssm final.jpg

  Imperial Metric 
A .535 13.59
B .555 14.10
C 30deg  
D .544 13.83
E .299 7.60
F 1.157 28.38
G .300 7.62
H 1.670 42.42
Max Case 1.670 42.42
Trim length 1.660 42.16

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We are a small, family run business, based out of Taranaki, New Zealand, who specialize in cartridge research and testing, and rifle accurizing.