A very nice essay about the Remington 740/742 and 7400 with a detailed description of the decades long battle that Remington was engaged in resolving the "bolt rail battering" issue.
Overall, nice rifles, dependable, fairly accurate, light and nice looking.
However the 740 and 742 seems destined to become wall hangers one day if they shoot enough rounds (still many people had them in hunting services for years)
A gunsmith can shave and repolish the rails a couple of time but eventually there will be no metal left.
So, if you buy one used, be aware that the infamous problem may have already show up...you can easily inspect the rails (remove the magazine, keep the bolt back and inspect with a light)
The 7400 seems to have resolved the issue (Remington slowed the velocity of the action)....still there is a bit of rail battering but way less than before and, because the bolt has now only 3 large lugs instead of the small 15, the impact surface is large enough to do not create a ding.
If used for many several thousands of shots, probably even the 7400 may eventually develop problems but that kind of usege is unlikely for the averge shooter and for the purpose that rifle was designed for anyway.
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The American sportsman has historically not much used semi-automatic rifles for his hunting purposes, but there have been a few successful models that some hunters have put to such good use that the guns have become legends. In 1955, with the U.S. now flooded with men that had become fond of the M1 Garand's power and reliability during their service in WWII and in the Korean War (let's face facts, it WAS a "war"), Remington introduced the model 740. The 740 was an instant success for Remington. Named the "Woodsmaster," it offered top big-game rounds, dependability, semi-auto firepower, decent accuracy, and a sporting appearance. With its sleek lines, basket-weeve checkered walnut stock and deeply blued steel, it was a beauty that no doubt haunted many hunters' dreams. It was a little pricey compared to the more traditional bolt actions and lever actions, but many hunters managed to get their hands on a 740. Those first few hundred 740s out the door were likely the talk of the hunting camps, and as others began seeing the 740s prove dependable enough for their buddies, more hunters went to get their own.
The 740 was issued in .30-06 Springfield. This initial chambering was one contributing factor to the gun's early popularity as there has probably not been a more "standard" big-game round in use in America, and that round had already proven itself with America's servicemen for half a century by the time it was offered in the 740. Soon after the initial chambering was offered, the chamberings of the .244 Remington (6mm Remington), .308 Winchester and the .280 Remington (7mm Express) were also offered. The 740 offered a 4 round detacheable box magazine, and came equipped with adjustable iron sights and was drilled and tapped for a scope mount. Since the ejection port was on the right side, the scope mount could be attached directly over and in-line with the barrel which was an added benefit to the design.
The 740 design used a gas pulse to operate a piston located beneath the barrel in the hollowed forearm. The bolt head pivotted in its carrier and locked secure inside a barrel extension instead of the receiver which was revolutionary for its time. To aid in its fast cyclic rate, the bolt used smaller locking lugs than guns normally did, or do today. But, it had a total of 15 of these small lugs which actually gave the bolt's lock-up more strength than many bolt actions and certainly better than the lever actions of the period.
After only a few years, Remington was hearing of complaints regarding one particular area of the gun, however. The top inside of the receiver had a long built-in rail on which the bolt body rode during cycling. The speed at which the 740 operated was causing the bolt heads to over-rotate when the bolt was at its rear most posistion. This was causing the locking lugs to hammer that rail to the point that dents were raised enough to cause the bolt to stick momentarily in the rear posistion. In bad cases, the bolt handle had to be forced forward to get the lugs unstuck. In the field, most shooters simply attributed this phenomenon to a "dirty" gun and would clean and oil it. The problem of course would not be resolved, and thus many shooters began to curse the gun that had been serving hunters so well for several years. In worse-case scenarios, the bolt would become locked solidly in the battered dents and would have to be disassembled to get the bolt out of the rearward posistion. To resolve the problem, Remington had to create another model.
The last year of production for the 740 was 1959. In just under 5 years of its production, with its 5 different grades of configuration, a quarter million 740s had been produced. But the "Woodsmaster's" saga had not ended.
The following year, in 1960, Remington offered the model 742. It also was offered in 5 grade variations, two of which were carbine versions with 18.5" barrels as opposed to the rifles' 22" barrels. Essentially, the 742 was the 740, except the action tube part's weight was increased in an effort to slow the bolt's movement enough to keep the lugs from battering the rail inside the receiver. Also, the barrel's retainer nut was changed with the 742 so a common wrench could be used to remove the nut and barrel. The earlier 740 model had a spanner nut that required a special wrench. The 742's tolerances were loosened a bit also so it was less sensative than the 740 had been to slight variations in the barrel nut's tightness.
The 742 was offered in the .308 Winchester, .30-06 and .280 Remington chamberings. The .244 Remington chambering was renamed as the 6mm Remington.
Still, the bolt lugs battered the reciver rail, however. The problem wasn't as bad, but it still happened. Generally, a 740/742 can stand about 1000 rounds before the bolt lug battering becomes problematic. A gunsmith can stone-polish the raised dents to allow the bolt to operate properly again. After a few hundred (perhaps 500 or more depending upon chambering), the battering will again cause problems. Gunsmithing can again fix the problem with stoning of the displaced metal. However, that is likely the final repair that can be made to the rail before it will allow the bolt head to over rotate and stress the carrier and link pin. The final repair may only solve the problem for a couple hundred more rounds. Since the rail is an integral part of these receivers, once they can't be repaired, the reciver, and hence the gun, is "dead."
Because of the inherent design flaw in the 740 and 742, Remington no longer will service these guns, and has classified them as "obsolete." This practice is fairly common among gun makers once models have been out of production for a few years, so there was nothing wrong with Remington doing this.
In 1981, the 742's long production run was ended. They had made a few small changes over the years, including changing the weights of the action tube as a counter weight, and changing the extractor a bit, but the model remained esentially the same. In total, Remington had produced just under 2,340,000 model 742s. Obviously, a lot of hunters still appreciated a decent sporting semi-auto rifle for hunting.
In 1981, Remington introduced a new variation, the Model Four (not 4, but Four). The Four was a 742 that had a clean look to it, and had a slight redesign to again attempt to end the problematic bolt lug battering issue. The Four was only made until 1988. Not as many of these were sold, but Remington doesn't have any hard figures available as to just how many were made. It was offered in .243 Winchester, 6mm Remington, .270 Winchester, .280 Remington, .308 Winchester (discontinued by 1984) and .30-06. The Four was actually a version of the 7400 variant, to be discussed later.
In 1984, Remington introduced the model 74 "Sportsman." It was only offered in .30-06, and was a base model of the Four. It was only made through 1987, and again, Remington has no hard figures as to the total production of this model available. The 74 was a more affordable option that Remington was using no doubt to compete for a shrinking hunting market against more competition that also were offering affordable guns and semi-autos.
Also introduced in 1981, and still in production today, was the model 7400. The 7400 never has had an official moniker, and really has not earned one. The 7400 is the best design of all of the 740 series. However, with a shrinking hunting market, and with more and more competition, the 7400 just never has become the legend that had its predecessors. The 7400 has essentially been a hunting tool where the 740 and 742 were considered more special.
The 7400 has been offered in 6mm Remington (discontinued in 1995), .243 Winchester, .270 Winchester, .280 Remington (7mm Express), .30-06, .308 Winchester, and .35 Whelen. The .280 Remington was labeled the 7mm Remington Express from 1981 until it was renamed the .280 Remington in 1988. The .35 Whelen has been the largest bore and most powerful chambering of the series. This chambering was only offered between 1993 and 1995 however due to lack of interest.
There have been 4 grades of the 7400 model, not including the Four and 74 previously discussed. A carbine version, with the 18.5" barrel like its predecessors had, as well as 3 rifles with 22" barrels. Some grades have had decent wood with a standard checkering pattern. Others have had oil-stained wood with fancier checkering. And still others have possessed synthetic stocks and matte blued finish. As with all of the earlier models, the 7400 comes equipped with adjustable Remington iron sights, and are drilled and tapped for scope mounts.
The biggest changes made to make the 7400 were designed once again around an effort to resolve the bolt lug battering problem. The action arms were beefed up to both strengthen them and to increase weight. The bolt carrier was permanently fixed to the action arms to strengthen the connection. The inertial weight was made lighter, but longer in an effort to spread the operation over a longer period of time instead of a sharper snap that the 740 and 742 created. The cone in the front of the weight (action tube) was increased to allow the gas pulse to expand more and thus slow the operation of the weight a little. A "flex arm" part was added to help secure the action arms which allows the parts to flex a very small amount and thus slow the operation yet some more. All of these changes have managed to slow the cyclic rate enough to virtually end the bolt lug battering problem that plagued the 740/742, but the problem does still exist. On 7400s I have inspected, all that have seen more than a few rounds have shown shiny spots on the rail where the lug contacts the rail. However, Remington removed the 15 small lugs in favor 3 larger lugs. This change increased weight on the bolt a little which once again works to slow the cyclic rate, but also serves to make the contact with the rail one wider impact instead of 5 smaller impacts. The wider striking surface spreads that impact over a wider area, and serves to keep the rail from experiencing the amount of metal displacement that the earlier models showed. I have never seen a 7400 that had enough lug battering to create a problem. This is partly because hunting rifles do not normally experience the number of shots that it would require to cause this problem anyway, but mainly is a result of Big Green finally making enough changes to have slowed the process enough that the vast majority of 7400s will never see the number of shots it would require to damage the rail. In short, Remington fixed the problem for all intents and purposes.
The other big change was the switch from using a barrel extension in which to lock the bolt head, to actually having the lug seats milled directly into the breech of the barrel. This allows the gun to handle higher pressures better. It also served to remove an extra piece.
There are many 740s and 742s still is service, and they should remain in service. The shooter should simply be aware that someday, the bolt will hang briefly upon the rail. After that begins happening, the issue will not be resolved with cleaning and oil, but will require a gunsmith's services. The shooter also should keep in mind that the problem will occur again in a few hundred shots, and eventually the gun itself will be relegated to a "wall-hanger" or a "parts gun" status. Also, when looking at a used 740/742 at a gun show or yard sale, the shooter should keep in mind that the gun will eventually die, and unless the seller can offer advice as to how many shots have been fired, or if any repairs have ever been done, the buyer should beware that the gun could be on the market because the problem is advanced. If the problem is well developed, sharply racking the bolt back and then releasing as fast and hard as possible can sometimes reveal the slight hang-up of bolt lug battering, but more often than not cannot reveal it if the problem is not advanced. Keep in mind that the magazine must be removed or the bolt will lock open.
All of these guns require a standard amount of care. The receiver, being closed, isn't prone to collecting water or debris in the field. To clean the gun, the action can be opened and locked back with the magazine installed. Simply clean the bore as normal, except it must be done from the muzzle unless a "snake" is used. The chamber especially must be kept cleaned and dried of excess solvent or oil. The speed of the cycling begins opening the bolt and thus extracting the casing while the brass is still expanded and gripping the walls of the chamber. Any solvent, oil, or debris in the chamber, or on the casing upon chambering and firing can cause the brass to sieze. The extractor on the bolt head is small, and can rip part of the rim off the case head, leaving the spent casing siezed in the chamber until the bolt attempts to feed the next cartridge into the rear of the spent casing. This of course will cause a serious jam.
To clean the open action, simply use a swab with solvent to wipe the bolt head and any accessible parts clean. A bent toothbrush also can be used to scrub parts. Dry the excess solvent from the parts that are accessible, and then apply a drop of oil on the operating rails. That is all that needs to be done for general maintenance.
The forearm can be removed to access the gas system. These parts should only be disassembled by a gunsmith, but the shooter can clean them as best as possible as above, and lightly lube the bearing parts' contact points.
Any feeding problems that these models experience are generally the fault of the magazine feed lips which can be bent. Magazines are still offered for these guns, so a spare should be obtained while they are available. A lost magazine turns these guns into unique single shots.
Accuracy of all of these models is about equal. None can become true target or varmint-class rifles. This is because the semi-auto action cannot lock each round secure each time the same way, and because the barrel is burdened by the gass system with its harsh and very violent operation shot after shot. However, as a big game hunting gun, it is more than adequate for most shooters' needs. Groups often can be kept to 1 m.o.a. but 1.5 m.o.a. is more usual. Again, however, this is all the accuracy that most hunters require. As a fast-handling brush or timber gun, the 740 series guns, and especially their carbine versions, shine. These guns offer plenty of short to mid range power with rapid follow-up shots. With the safety posistion above and behind the trigger as with the other similar Remington trigger groups (870, 1100, 760, etc.), the gun can be put into very quick action. While the cartridges offered do have decent long range power for medium sized big game, the accuracy may not be sufficient to allow ethical shots. This decision however can only be made by each individual shooter with regards to their own skills and the loads they have chambered.
The 7400 shows no signs of being discontinued anytime soon. It is a strange mixture of an old design that probably should have died off long ago except that it has had a reputaion as a classic hunting arm for so long, and newer designs that deserve to remain in service for some time to come.
There are many shooters that now disparage the 7400 out of memories of problems they or others had with its predescessors, or because they have personal prejudices against semi-automatic hunting rifles or the guns' appearance. However, all of the guns are unique and deserve respect as hunting rifles. With proper care, they operate very well, and with sufficient accuracy to satisfy just about any hunter. I must admit to being one that once disliked the 740 series based upon their looks, but after learning about their design features and even their problems, I have gained respect for them. The 7400 variants are the best of all the variants, but for me, it is the classy looks of the 742 Woodsmaster series that I most admire, problems and all. As long as one knows the quirks in the gun, a fond appreciation can develop with any of the models. With appreciation, even a gun with some quirks can earn itself a fond reputation from its user in the woods.
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I'm not sure how much it was shot, but knowing my dad, he probably didn't clean it. Ever. 
