As a followup to the question on the Remington Mod 8 and the 'first' successful autoloader, I did a bit of research and some cut and paste (Shamelessly!) and here is what I found re the "wind-Changer" self loaders:
“This thread will generate a yawn from most of the readership but there are a few things to consider about the old .351 Winchester S.L. (self loading) round so it bears a look-see. Perhaps someone out there in NOR land is wishing to reactivate one of the Winchester Model 1907 rifles and maybe this will encourage them to do so. Besides, I like this old underdog of a round.
The .351 Winchester was brought out in 1907 as the latest and greatest incarnation of the line of self loading rifles Winchester first introduced in 1905. The Model 1907 later designated as the Model 07 in Winchester catalogues was the only gun ever to chamber this round. Because of this the rifle and cartridge are so intertwined that they will be discussed together The Model 1907 must be given credit as the first successful semi-automatic rifle marketed in the US. Its immediate predecessor the Model 1905 was not a commercial success as it was chambered for a couple of low velocity, ineffective rounds, the .32 S.L. and the .35 S.L. Few of these rifles were sold and the last ones were moved in the early 1920's probably made up from pre World War I parts. Another model rifle of the self loading design the Model 1910 was chambered for the fairly potent .401 S.L. and represented the limit of the design. Better known for his developmental work on the famed Model 12 pump shotgun T.C. Johnson was the main designer of the rifle. It features what is described as a hesitation blowback system. It is a simple system where the bolt/breech block is held against the rear of the chamber by a spring and is extended forward into the forearm in the form of a heavy weight. This massive one piece apparatus is the secret of the rifle's operation. It is heavy enough to provide the inertia to keep the action closed until the much lighter bullet has exited the muzzle. There is no locking lug. It doesn't require heavy recoil springs, is simple to manufacture, and is easy to maintain. Its main drawback is that the ammunition must be very uniform in order to function it properly. This weighted bolt must be increased in mass if the design is adapted to more powerful cartridges. The .401 represented the upper limit of practical size and weight. It was calculated that if a rifle of this design system was made to fire the .30-06 the bolt would have to weigh 42 pounds. Perhaps the best thing about the design was that T. C. Johnson managed to get around John Brownings patents for his recoil operated semi-automatic design.

"The Rifle That Shoots Through Steel"

This was the slogan adopted by Winchester in the original advertising that accompanied the rifle's debut. The fact that the steel plate used was 1/4 inch thick was overlooked in the ad's copy. Still it isn't a bad round. Sort of a .30 carbine on goat glands. Employing a 180 grain bullet of .351 diameter at a velocity of 1850 fps, it yielded 1370 foot pounds of energy. I chronographed some of the last Winchester factory ammunition I purchased at retail and obtained a velocity of 1924 fps. See, it offers practically the same velocity as the .30 carbine but also offers the additional punch of a larger, heavier bullet. There is nothing else quite like it now available. This intermediate cartridge is housed in a compact, rather sleek, modern, and attractive rifle that also has a very businesslike look about it. To its detriment it is very heavy for its size. Fortunately it is well balanced so carries nicely in spite of its weight. The rifle is very finely fitted and the machine work and polish is excellent. It is designed with a take-down feature which is an aid for cleaning and maintaince. “

“Winchester’s first semi-automatic rifle was the Model 1903 blowback in .22 caliber. Since standard .22 bullets were not uniform as to powder charge, this often resulted in the ’03 failing to reload. Winchester then developed a uniformly charged—as much as possible—automatic cartridge that should have sent sales through the roof. However, due to the need of the special cartridge, trade was slow, and only 123,000 or so were manufactured by the time the rifle was discontinued in 1936. (4)
The ’03 was followed by the .32-caliber Model ’05, which utilized the same basic design. Although Winchester had spent two years developing a blowback that fired a heavier cartridge, the ’05 was still underpowered. Therefore, regular production halted after serial number 29,113 in 1914. (5)
The Model 1907 was Winchester’s answer to its customers’ requesting a self-loader capable of firing a more powerful round. Its .351 caliber, capable of penetrating a quarter-inch steel plate, (6) became the company’s bestseller of the blowback repeaters, with a production run in excess of 58,000. (7)


The ‘07 maintained Winchester’s attractiveness in its symmetry, beauty, and compactness, while still being simple and strong. The working parts of the rifle are few and tough. There are no moving projections on the outside to catch clothing or tear hands, no screws or pins to shake lose, and the attached sights offer the shooter championship accuracy.
After serial number 18,300 (1909), heavier stocks became standard, and the ‘07 was regarded as a lawman’s rifle due to poor civilian sales. (8) The detachable magazine holds five rounds.


10-Round Magazine
Ten-round models were available for $3.50 but had to be fitted at the factory. Because of its weight (7 ½ pounds) and cost ($28), the self-loader was available with a twenty-inch, round, nickel-steel barrel only and in plain, pistol-grip, walnut stock. A “fancy walnut, checked†stock and forearm could be purchased for $48. (9) Police rifles were produced with sling swivels, heavier stocks, checked-steel butt plates, and bayonet attachments upon order. (10)
The barrel makings appearing on the 1907s during production varied. Early markings are found on top through the first 17,300:
MANUFACTURED BY THE WINCHESTER REPEATING ARMS CO.
NEW HAVEN, CONN. U.S.A. SELF LOADING MODEL 1907. PAT. AUG. 27.-.351 CAL.
DEC. 10, 1901, FEB. 17. DEC. 22, 1903. AUG 21, 1906. OCT. 30, 1906.


Barrel Markings
After number 7,100, this additional marking is on the left side of the barrel:
-NICKLE STEEL BARELL-
ESPECIALLY FOR SMOKELESS POWDER
Model ‘07s approaching number 17,300 may have the last line of patent dates replaced to read:
AUG. 21. OCT. 30. 1906. JULY 5. 10
By number 3,500, the added line and changes became standard barrel markings on the left side. After number 24,300, nickel steel was replaced with:
-WINCHESTER PROFF STELL-
Somewhere between number 47,900 and number 48,300, this marking became standard until the end of production:
MADE IN NEW HAVEN. CONN. U.S. OF AMERICA—WINCHESTER-MODEL 07-.351 CAL.
-WINCHESTER PROFF STEEL-TRADE MARK-
Tang markings through number 15,900:
WINCHESTER
TRADE MARK
MOD. 1907 S.L.
After number 15,900:
WINCHESTER
TRADE MARK
REG. IN U.S. PAT OFF.
MOD. 07 S.L.
After number 27,100 until production end:
WINCHESTER
TRADE MARK
MADE IN U.S.A
MODEL 07 S.L.
The ’07 was not only popular with lawmen such as the Texas Rangers and F.B.I, but also with the outlaws such as Bonnie and Clyde, Machine Gun Kelly, and John Dillinger. World War I Allied flyers whose copilots fired at German aircraft from the rear seat also used this weapon. (11)â€
So, with special thanks to those I 'Borrowed' this info from, here is probably more than anyone ever wanted to know about the Winchester Self Loaders.

Great info.

I have about 10 of these guns around the shop in disrepair.
I have alway thought about fixing one up.

-Spencer

TrapperP,Great info,thanks for posting this.i ran into some of these old rounds and couldnt figure why they were not being used in t/c pistols or lever guns.The little rounds look like they would be great fun to shoot!would love to have a little carbine auto loader that shoot this little devils!sad they didnt make it on the shooters market......

It would eventually turn out not to be a favorite of Bonnie and clyde when two of the 4 lawmen used these to mow them down.They were trained on bonnie,the 30 cal bar at the engine compartment to disable the car,and the buckshot loaded model 11 remington at Clyde..Thats right folks,not a tommy gun to be found despite what hollywood says.

PS
How many have you seen without cracked forends?

The ones that I have, many are missing the wood altogether.
I would say 1 or 2 maybe have in tact wood that has been shipped but not cracked so much.
Some have split wood all the way down the sides.
I don't think this would be a problem if the grips weren't so thin.

Curiously, a couple wear a hammered out piece of sheet metal as their handguards. I guess someone got tired of spitting wood and decided to make their gun a little more sturdy.

-Spencer

New to the forum here.

I've had a couple of the Model 1907's and currently have a really nice one with its forend intact. Have taken one deer with it here in Texas. A single good hit proved the .351's effectiveness. Mine was given to me by its original owner who purchased it new in 1923. He paid $42.50 for the rifle, two boxes of ammunition, a bottle of Winchester Crystal Cleaner, and a cleaning rod.

BMc;
Isn't that all YOUR research at the top of this thread? It sure looks familiar from the NoR site!!

Didn't you learn in high school to always cite your sources? All that information was taken from this website. The author of that webpage derived most of his information from George Madis' The Winchester Handbook.
Now, I've been researching the Winchester Self Loaders for two years now and have found out most of what there's to know about this rifles, so please allow me fill you guys in.

The Winchester Repeating Arms Company originally had two designs for self-loading firearms. First William Mason and T. G. Bennett developed a toggle-link design much similar to Hugo Borchardt's pistol design. They made a .44 semi-rimless, centerfire caliber carbine and a 20-gauge shotgun off the design principle. (Patent Number 695,784). Encountering numerous extraction problems with the shotgun design, the company decided to stop work on perfecting this comparatively complex design.

Thomas Crossley Johnson had been designing a inertia-delayed blowback rifle at the same time and had been achieving success, patenting the Model 1903 in 1901. A much simpler design, the company decided to continue with T.C. Johnson's design principle in making the Model 1905, 1907, and 1910 self-loading rifles. He used the .44 Semi-rimmed cartridge developed for the Mason-Bennett carbine as a jumping off point for designing the 32 WSL, 35 WSL, 351 WSL, and 401 WSL cartridges. (Winchester Repeating Arms Company, 1860 - 1981 by Herbert G. Houze)

The Model 1905, first patented with the number 694,157 in 1902, was brought to market in 1905 with a great deal of press attention. (Henry M. Stebbins, Rifles - A Modern Encyclopedia) 22,213 were made within the first three years of it's production. That's more than the 1910 or even the 1907. Unfortunately, the 32 WSL and 35 WSL cartridges were only as powerful as the 38-40 and 32-40 blackpowder cartridges of the late 1800's, not meeting the high expectations that many folks had of the new smokeless powder. The 32 WSl pushed a 165 gr. bullet at 1392 ft/s muzzle velocity. The 35 WSl, a 180 gr. bullet at 1396 ft/s muzzle velocity. The modern hunter demanded more performance, especially as the Remington Model 8 was introduced in 1906 chambering the Remington Rimless series of cartridges. (Townsend Whelen, The American Rifle)

Thus, the Model 1907 was introduced with the 351 WSL cartridge pushing a 180 gr. bullet at 1861 ft/s. Obviously, it proved to be much superior of a rifle/cartridge combo than the Model 1905 rifle. Therefore, the Model 1905 fizzled out of production after WWI.

Now the Model 1910 was developed with an eye towards big and dangerous game. In advertising, Winchester promoted it as an elk and brown bear rifle. The 401 WSL cartridge pushed a 200 gr. bullet at 2141 ft/s and a 250 gr. bullet at 1875 ft/s. Because of difficulties with penetration in the soft-point offering on large game, it being a large, short bullet for the caliber, Winchester quickly dropped the advertising claims. On lighter game, the .406" diameter bullet in the Full Metal Jacket offering, failed to consistently expand. Naturally, this was a common difficulty with most new smokeless powder, high velocity cartridges of the time. Teething troubles, right?

Now because of the inertia delayed blowback action, this rifles necessitated a big chunk of moving steel hidden within the forearm. This breechblock extension weight was finely calculated with the recoil energy of the cartridge to ensure that the action opened after the igniting powder gases have ceased to expand. For handloaders, if you used too hot of a load, the action would open prematurely and spit hot gases out the ejection port. If you use too light of a load, the action will not cycle in semi-automatic.
Nevertheless, these rifles were highly regarded as extremely reliable with factory ammunition and have been used all over the world in many climates and weather conditions. Many went to South America for the rubber plantations, some to Alaska and Canada, and even in WWI, some were bought by Britain, France, and Russia for arming airplane pilots. France and Russia had some for special shock or assault troops to be used in the trenches. (Herbert G. Houze, American Rifleman May 2003)

This site is not a learned publication. People can cut and paste from other sites and sources. I don't care if someone fails to provide a BlueBook cite in proper format on what they post. I appreciate the information.

Not to be combative, but I sure appreciate it when people provide leads to where they found their information, especially this being a research thread, otherwise, it's just plain old hearsay and ALOT of that's been not only hashed out on the internet, but in print by a number of the famous gunwriters. AND I'm only thinking of the Winchester Self Loaders...