During the late years of WWII, the US military worked diligently on a replacement for the M1 Garand rifle, which was designated the T20. This was basically an M1, with the addition of a trigger group allowing full automatic fire and with a 20-round box magazine in place of the M1’s 8-round clips. As long as the war continued, this project was pursued with some sense of urgency, and rifles were being actively tested in 1945 and late 1944. By May of 1945, the Ordnance Technical Committee actually recommended procurement of 100,000 T20E2 rifles – a sure step towards their general adoption. However, the war ended a few months later, and the project was no longer particularly time-sensitive. The large order of T20s was not formally placed, and the immediate plans to replace/update the M1 rifles in service were all shelved. Instead, it was decided to pursue a new lightweight rifle program based on the developmental T65 cartridge (which was to become the .308 Winchester and 7.62 NATO). The Olin Corporation had developed a new type of ball powder which would allow the Army to duplicate the performance of the .30-06 cartridge with a half-inch shorter case. This was seen as a valuable way to reduce rifle size and cost.
The head of US small arms R&D, Colonel Rene Studler, anticipated this change of focus, and in March of 1945 he assigned a 37-year-old designer named Earle Harvey to study the characteristics of military breech locking systems and develop an ideal light rifle. Harvey had been toying with designs in his own time since 1942, and he dove right into the project. By the end of 1945 Harvey had a completed design for what would be known as the T25:
Harvey was a skilled designer, and his previous work included a new gas system for the M1, which was made as the experimental M1E9, and would eventually be used in the M14 rifle. He used that gas system in the T25, along with a tilting bolt mechanism which locked into the top of the receiver (somewhat like a Bren LMG). Since the force of firing would push this type of bolt directly back against the locking shoulder in the receiver is would put the bolt in compression. A rotating bolt like the M1 used, by comparison, puts a large shear force on the bolt’s locking lugs, which requires tougher steel and more machining to construct. Harvey judged that his tilting bolt would be both stronger and cheaper than the M1 bolt – and was right, too. In a firing test on May 18, 1948 the T25 was found to withstand chamber pressures of 125,000 psi without an increase in headspace, and pressures of 150,000psi without any parts breakage.
Harvey also considered several other important factors in his design, including simplicity of manufacture. Given the new nuclear dimension of warfare, the component parts of the T25 were designed to be fabricated with generalized tooling and machines as much as possible, so that production could be distributed to numerous small shops in case of a nuclear strike on the US. Harvey was also very conscious of weight in the rifle, and made use of aluminum and deliberately lightened designs for parts not under direct stress (like the buttplate and trigger guard). The result was a full-power rifle (it was chambered for the 7.62mm T65 cartridge) weighing a mere 7 pounds (unloaded) – a significant technical accomplishment. To mitigate the recoil from such a light overall weight, the design utilized an in-line stock and muzzle brake.
The first four prototype T25 rifles were made under contract for Springfield Armory by the Bennel Machine Company out of Brooklyn, and first completed rifle was test fired in January 1948. A more formal endurance test in April 1948 saw 3500 rounds put through gun #3, with no parts breakages or weakened components. By August, Col. Studler was contracting with Remington for more prototypes to be made (12 were delivered in December 1949, having been delayed several months by design changes). Another 110 were ordered in the summer of 1949, although this quantity was shortly revised to just 50. Production of these early guns was repeatedly delayed by changes requested by the Springfield Production Engineering Branch, as being necessary to make the rifle practical for mass production.
In actual fact, the T25 was no more complex to manufacture than the M1, and the delays to prototype production were founded in an administrative bias at the Armory again new development, rather than actual shortcomings of the T25 design. The final lot of rifles made be Springfield Armory was finally delivered in the summer of 1951. This bias against the rifle would come back to haunt the T25 as one of the main reasons behind its cancellation…
Army testing of the T25 began in September 1948 at Aberdeen Proving Grounds, and the results were quite good. In the first test, the T25 was found to be more accurate than the M1 rifles used as a baseline, and to operate well under adverse conditions, considering its current level of development. Problems were reported with firing pin breakage and erratic ejection patterns, but nothing was particularly surprising or could not be fixed with some more work. In 1949, the decision was made to also restart development of a lightened M1 rifle, and for the following three years (1949-1951) that project would run parallel with the T25.
The next Aberdeen trials were in February, May, and June of 1950, with the T25 competing against the FAL and EM2 rifles (both in .280 caliber). The T25 showed some weakness in some adverse condition tests, but outperformed its European rival in others. It did have problems caused by poor-quality ammunition, as the batch of T65 ammo supplied for the testing gave erratic pressures. It also had problems with some improperly parkerized parts, and performance improved in the last parts of the testing after these parts had been replaced. Overall, the T25 was a fundamentally sound rifle in need of more development work. Earle Harvey was the only engineer assigned to the T25 project, and he had significant other duties as well. The quality of the rifle is particularly impressive considering the limited time and money that was allocated to it, and it reflacts very well on Harvey’s skills as a designer.
Ultimately, internal administrative bias towards the existing M1 rifle led Col Studler to decide to drop the T25 program late in 1951 or early in 1952, although this decision still had to be made to look like a fair and objective choice. Another round of testing was scheduled for 1952, to include the T25, T44 (Springfield’s product-improved M1, which would eventually become the M14), the Belgian FAL, and the British EM2. Harvey was unable to get the time and engineering assistance necessary to iron out the issues with the T25, as intended by Ordnance Department higher-ups, and the result of the testing was the T25 (and EM2, for what it’s worth) being formally dropped from consideration.
For all the work and political maneuvering of the T25 and T44 (and the other shorter-lived experimental rifles of the period, including the roller-locked T28 and John Garand’s bullpup T31), the program was ultimately doomed to failure. The entire premise of the light rifle program since its inception in the autumn of 1945 was to devise a single standard rifle which could serve as light machine gun, rifle, carbine, submachine gun, and sniper rifle. It became clear to Harvey and the other designers, as it should have been clear to everyone, that the requirements were contradictory and impossible to fulfill. A 7-pound weapon using a full-power cartridge could never be an effectively controllable LMG, and the same gun would yet be too large and heavy to be an effective replacement for the M1 Carbine. The T25 was repeatedly found to be too light to be controllable in full auto, but the design requirement was never altered. This giant elephant in the room of the light rifle program was studiously ignored clear through the adoption and mass production of the M14 rifle, and only really addressed with its replacement by the M16.
The least successful general-issue rifle ever. Sad.
Which rifle was that? BTW, the light rifle program was in direct contradiction to the studies produced by the Germans, British, Soviets and Americans showing that full power rifle caliber rounds were overpowered for general infantry use. These studies showed 1) that most firefights happened at less than 350 meters, regardless of terrain or conditions, because most targets were spotted and engaged at less than 350 meters 2) most infantrymen, regardless of length of training, could accurately engage targets beyond 350 meters, 3) that targets were exposed only for very short time, 4) that very high velocity small caliber rounds were more accurate out to 350 meters because of their flatter ballistics and caused more traumatic wounds, and 5) the base of fire for a squad should be a light or general purpose machine gun firing the full power round, the MG suppressing the target while the rest of the squad maneuvered and then conducted a close assault, where automatic weapons firepower and grenades were more important than semi-automatic rifles capable of long range fire. Later studies by the Israelis confirmed this outcome. These studies were produced before 1959, when the M14 was adopted. The M16 and other light selective fire rifles chambered for the 5.56 x 45mm meet the requirements postulated by these studies, especially given the wound ballistics of the 5.56mm M193 round. The British recognized this with their 7mm round and the EM2 assault rifle, as did the Soviets who first adopted the AK-47 in 7.62 x 39 mm and later the 5.45mm round, which was deliberately designed to tumble on penetration of the human body. US Army, and especially, Marine Corps officers and NCOs wedded to the full power round, what some have called the “gravel belly” or Camp Perry clique have repeatedly resisted these studies. One of the results was production of the M885 round which reduced the wound ballistics for more penetration and modifying the M16 with a heavier barrel so that the sling could be used for deliberate aimed fire and no full auto selector, only three round bursts “to prevent troops wasting ammo”. As far as the experience in Iraq and Afghanistan, the problem there was lack of BOG which meant commanders were using squads without GPMGs to perform tasks that should have called for platoons w/GPMGs. What should have been done was to retain the M193 round and modify the M16 for a cyclic rate to produce more rounds fired at a target to increase the chances of a hit, while fielding 13 man squads with a GPMG rather than repeatedly reducing squad size to fit the maximum force structure into authorized strength.
I meant could not engage and hit a target over 350 meters.
The Army wanted the 30-06 because machine guns were used for long range support back before mortars were common (now mixed with grenade launchers and even TOW missiles)
They did see the appeal of the .276 round in a rifle- but backed off during the Depression- an understandable, but unfortunate cost savings.
THey discovered later that all rounds oscillate in flesh, though the 5.56mm does so in a lot shorter distance (~4″ vs ~12″) than 7.62mm.
Really interesting design, with obvious FG-42 influences. I wonder if anyone has ever tried to reproduce any of these old prototypes? You could design a custom stock for standard M1 Garand, and install sights like this. I once saw a special stock that makes an M1 Carbine look like a Thompson.
Interestingly Stoner owned an FG42 and talks about it in short length as to how it functions but merely calls it a “German automatic” and shot it outside his house along with his newly just made AR15 prototype (I’m just calling it that, not being more specific for length issues), and another machine gun I can’t remember, and I can’t find my book that talked about this either 🙁 I think it was a Bren, but not 100% and all I’m thinking of as I read this was, “god almighty they talk like it’s the most mundane thing,” for reference, the only FG42 I’ve seen for sale was 285k starting price at auction and that was almost a decade ago, wonder where Stoner’s is. ..
Probably in Reed Knight’s collection!
Anyone know where blueprints for the t-25 could be found? I’m intrigued by the possibility of a semi auto version!
There is and excellent book on US small arms development and acquisition called “Misfire” by William Hallahan. Much or the troubles were due to the Board of ordnance in its different iterations, refusing to accept new ideas & technologies and when finally doing so, ruining the process with micromanagement, the “Gravel Belly” attitude, penury and just plain ignorance. A good read.
CB in FL
I’m also interested in seeing those blueprints… Anyone know if the T25 influenced the design of any other guns, civilian or military?
I have always wondered why the 6mm was never considered.I know in the late 19th century the USN used a 6mm Lee rifle and found it not powerful enough.But with modern powders a 6mm(243/244) could fire 110gr bullets at 3000fpm and make for a very deadly round out to 500yds.The 243 is a very popular medium game round and it seems to me that its smaller size and weight would make it possible for infantry men to carry about the same amount of ammo as they do for the 5.56 round.Has the 6mm ever been proposed?
Well, I actually believe that a 6.5 or even better, a 6.8 round should’ve been designed for the rifle that would replace the M1 Garand. Personally, I believe that they rushed things A LOT when they decided to adopt the AR-15 as the M16. If they wanted to replace the M14, then they should’ve taken their time. The Ar-15 was rushed into service without even being tested. I believe that this design, the T25, chambered for a 6.5 or 6.8 round would’ve been much better than the AR-15 to replace the M14.
They couldn’t take their time. Thanks to the Eisenhower Administrations concentration on strategic nuclear warfare and the Army’s fumbling of both the Light Rifle project and M14 production, the US Army’s berlin Brigade and the Battle Group intended to reinforce it in 1961-62 was still armed with M1s. This was four years after the M14 was adopted. That mismanagement allowed McNamera to step in and push the AR-15 after it had been successfully tested and fielded to both the US Air Force and the ARVN and the projections by the SALVO project on would ballistics of high velocity small caliber “spritzer” type bullets were proven. Colt was ready by then to mass produce the AR15. The travails of the AR15 (M16) after 1963 was a result of DoD and Army mismanagement (the change in powder, lack of spare parts and cleaning kits, training, etc) and Colt’s refusal to sell the production package to the Army for distribution of production contracts.
You are mistaking something about the .243Win, because its case is the same size as the .308Win/7.62NATO the number of rounds an infantryman could carry compared to 5.56NATO is a ratio a bit closer to 1:2 than 1:1, and as long as tactics are dependent on all the riflemen producind a high volume of fire that is also significant throughout the logistics chain getting the ammo to the infantryman. (A 6mm bullet can be used in a smaller cartridge case, but the ballistic trade-off is a another question, haven’t looked at that myself, yet.)
Actually the 6mm Navy Lee is beloved by those who collect and shoot it, and of all the archaic rounds I see, that one is always for sale along with the 7.5 and 6.5 Arisaka in magazines, with the rest being the usual far more popular suspects, so it’s STILL popular enough to warrant manufacturing in numbers, never having shot one myself though nor loaded for it, nor even held the round IRL, I cannot give a personal opinion but I can answer as to why it wasn’t adopted like so many other logically better things than what was issued, just like a slew of other military items from calibers to canteens, to torpedoes and so much more, it’s often due to politics, and favoritism… The 6MM has an interesting story that’s too much for me to cover and I’m not a big fan of it myself, but if you ever read this there is a book about that round, though remember there are other 6MM rounds, even of the same name there was a British 6MM Lee and an American 6MM Lee lol extremely confusing, not even 100% they were different but were listed different so guess they were, go check out the book I think it’s name is bluntly like; The story of the 6mm Navy Lee
I can imagine if the Board ever understood that a 7 pound rifle firing a full powered cartridge won’t be very controllable in full auto and didn’t have such an anachronistic erection for a rifle designed in the 30’s (maybe even actually going back to the original development of an intermediate 7mm), the T25 or its conventional stocked T47 would have become a pretty nifty service rifle. Shame it never got the chance to fully mature.
so the t25 was a short stork gas piston with a tilting bolt that was lighter than a rotating bolt gun. someone should make a semi auto version, he would make a lot of money.
and it looks like the tilting bolt is both stronger and cheaper than the rotating bolt. so why is the rotating bolt system much more popular as to be the dominant locking mechanism for gas operated guns? is it because bolt action rifles are rotating bolt and so there is a bias among fire arm designers for rotating bolts?
A few things:
1) The bolt wasn’t tilting, The bolt had two major parts the bolt head, and a locking flap. The operating rod cammed the locking flap up into a recess in the top of the receiver.
2) The gas system is the “gas cutoff end expansion system” whereby a metered quantity of gas is bled from the barrel, trapped, and allowed to expand in a gas cylinder end piston arrangement. The advantages of this actuating system lie in the facts that-the applied power may be regulated as to magnitude, duration, and rate of application. Since work accomplished is the product of force and distance it will be seen that in this system, forces of a relatively low order acting over a relatively long distance produce operating energy equivalent to that produced by the conventional gas piston which gives a very short impulse of high intensity.
Why are rotating bolt preferred? Tilting bolt aren’t necessarily cheaper to produce. The T25 bolt design requires a rather close tolerance in between the bolt head and locking flap (it very similar to the locking system used on the M61 Vulcan), and the rotating bolt head of a AR-15 or .308 AR is probably easier to produce in quantity.
The other disadvantage of the tilting or flapper locked bolt is there is little or no slow initial extraction. The extractor has to snatch the spent case from the chamber in one quick jerk. With slow initial extraction, the case in first broken loose through part of the unlocking then extracted. The loads on the extractor are much larger if you do not have slow initial extraction. Also, with a true tilting bolt, the face of the bolt is not parallel to the base of the cartridge during some portion of the cycle.
3) Everyone always states or implies there was some conspiracy, towards the M1/T44/M14. However, certain facts are continually overlooked, or simply incorrectly put forth. In regards to the testing of the T25 against the EM2 and FAL, the 1950 test results state: “Of the 3 models tested, the EM2 gave the best performance in the dust, mud, cold, dry and automatic accuracy tests, but gave the poorest performance in the disassembly, sea water immersion, salt spray, rain, elevation and grenade tests and gave the greatest number of parts breakage in the endurance test. The FN rifle gave the best performance in the disassembly, endurance, salt spray and flash (with flash hider) tests but gave the poorest performance in the semi automatic accuracy and cold test. The T25 gave the best performance in the rain, elevation semi automatic accuracy, sea water immersion and grenade tests, and was the only rifle to complete the cook-off test but gave the poorest performance in the mud, dust and dry test.
. . .
The ejection pattern is erratic . . . from 11:00 to 1:00 o’clock during automatic bursts and have been struck by bullets
. . .
It is concluded that . . . No model was sufficiently developed to give its best performance.
. . .
It is recommended that . . . The desirable features of all tested rifles be combined and incorporated in future model”
In short, the T25 was far from “acceptable” or “good”.
4) And last – While the T25 was abandoned at the end of 1951, the design development was continued in the T47, which introduce may simplifications into the design, such as eliminating the open-bolt full automatic mode. This design was considered a higher development risk that the T48 (FN FAL) and the T44.
There simply isn’t a perfect infantry rifle caliber. I was a Ranger/LRRP and a four man recon unit usually carried two 5.56 M-16’s, and a cut down M-60 7.62 belt fed, and the trusty “Elephant Gun”, the M-14 in 7.62(often with a brown plastic stock!). Special Forces asked for and received a reworked Eugene Stoner SR-25; effectively an shortened M-16 platform in 7.62 NATO. The two latest rounds being used are the vaunted .338 Lapua for accurate distance shots with deadly punch and the favorite of Army and Marine snipers. H&K has developed the 4.6 x 30mm for their carbine and PDW that has a high muzzle velocity with penetration and defeats all things Kevlar. So you see, there is no one-size-fits-all infantry ammo as we found out in Viet Nam, as the Brits found out in the Falklands (FN-FAL), and as coalition forces have found out in the Middle east conflicts. The fact that the current M-16/M-4 no longer has an “auto” setting but a choice of single or three shot bursts tells us something about automatic fire in assault rifles. Both the M-14 and the FN-FAL were impossible to control when fired automatically. Hopes this helps.
It can be argued that the “three round burst” option was adopted in lieu of proper troop training in fire control and application. Unless aimed at adoption by the US military, no other selective fire individual weapon in production or service uses a “three round” burst selection. In fact, when the Canadians adopted the M16A2 as the C7, the replaced the “three round” burst selection with full-auto.
The USAF GUU5P I was issued in 2008 still had full auto.
Just remember you all are comparing apples to oranges some what. The m-16/ ar-15 is an assault rifle. The m-14/M1a is a battle rifle. There is a slight difference. As you have said before there is no do it all rifle cartridge. It still comes down to proper breathing, proper stance, trigger control, and sight picture.