Remington 740/742/7400 Semi-Aut

Model 740: The Remington model 740 with a 22" barrel & a detachable 4 shot box magazine that was introduced in 1955 . This magazine was designed so that on the last shot the action remained open. In reality the only reason for this was so you could have the action open for cleaning, as in normal shooting, after the last shot, you now have to push the follower release button allowing the bolt to go forward before you push the magazine release button to remove the empty magazine. It was produced initially in 30-06 & 308 calibers with 244 & 280 coming available from 1957 until this model died in 1959. The wood was plain uncheckered walnut. It had a receiver mounted pivoting bar type ejector. There was a 740A in the product line & I suspect it was simply a 740 that used the newer plunger type ejector.

The early 740s were not drilled & tapped for a scope. The later guns being tapped for the Weaver #62 scope base. Also there was a 740ADL which was similar to the 740A but had a checkered stock, pistol grip cap & sling swivels. The 740BDL was similar to the ADL but had select wood.

One problem with this firearm was that the forearm attachment screw was a single pitch thread, pulling the forearm tight against the front of the receiver. When firing rapidly the 2nd & 3rd shots seemed to always climb & the gun would shoot higher with each successive shot. Williams Gunsight Co. made a aluminum spacer that went on the forearm screw & between the metal forearm liner & the gas nozzle block, making the forearm float at the rear.

These forearms are rather thin wood that is glued onto a sheet-metal liner as reinforcement.

Model 742: The 742A superseded the 740A in 1960. It was produced in 244 Rem. (6mm Rem.), 243, 280, 30-06, & 308. The normal barrel length was 22" & a carbine version that had an 18 1/2" length. The receiver was again drilled & tapped like the later 740A guns. The checkering on the wood was a pressed in design. It was also made in a BDL or deluxe version that had a cheekpiece on the buttstock & basket-weave design for the checkering to differentiate it from the ADL. It had a longer flat on the top rear of the receiver with a small flare at the rear. It was also made in a Left Hand version.

Sights were improved & Remington's own rear sight with a sliding dovetail ramp for elevation & a cross dovetail for windage was implemented.

The 742 incorporated a different forearm attachment screw which had a dual pitch thread. When installed correctly the 2nd pitch threads pulled the forearm slightly away from the front of the receiver, making for more accurate shots after the barrel warmed up.

The 742 has an improved bolt system incorporating a bolt latch system, which is a small thin lock that holds the bolt head from rotating out of battery while it is traveling rearward & forward during cycling.

In Feb. 1977, date code (LO), on the 742 & 760, the barrel threads were changed from RH to LH, to help stop the problem of the barrel extension (locking lugs) from unscrewing from the barrel during the firing cycle. This date code is shown below in the gunsmithing section.

Gunsmithing These Models: These firearms are now obsolete & if you contact Remington, they will say they don't have any parts. As a matter of fact they don't even have the part numbers in their parts computer system anymore or if they do it does not reference to these 740/742 models.

If your gun does not fire when you pull the trigger, but may on a second pull, you very likely have could have a gunked up trigger housing assembly. By the nature of this gun, with the magazine well being open & the operating port somewhat open, debris can accumulate in the bottom & in the trigger housing. If there is any oil also accumulate there, over time all this can harden into something that may restrict movement. This could be the safety itself or even the hammer plunger. Thus plunger is spring loaded & if it gets gummed up may well become sluggish, resulting in a delayed firing.

Be sure the gun is unloaded, use a long punch & tap our both the 2 cross pins holding this unit in the receiver. It should then come right out the bottom. Now you can manually cock the hammer, with the safety off, try to simulate your problem. You could find something restricting either the trigger from being pulled (safety) or movement of the sear to disengage the hammer.

If it is in the safety, there is a small cross pin in the metal housing above the safety, This pin only holds the spring & either a ball bearing or plunger (depending on vintage). Drive it out, & carefully remove the spring & plunger. Now the safety itself can be removed. REMEMBER WHICH WAY IT CAME OUT. Clean, oil with a light oil (NOT WD-40) blow all the excess off the internal parts & reinstall.

In operation on these 742 models, as the bolt moves out of battery the bolt latch locks the rotating bolt head, keeping it from rotating. This latch lies in a slot in the bolt body. The front of the latch has a downward angled front ear that goes into a recess. Directly behind this front angled recess is a small hole the dia. of the slot. There is a spring loaded (.087dia.) pivot pin that goes into this hole with a spring under it. This pin has one rounded end. This rounded end goes UP to act as a pivot for the latch. There is also another hole in the rear of the slot. The pin that goes into this slot also has a spring under it. But this plunger has BOTH ends square, as the upper end acts as a retainer against a square matching notch in the underside of the latch. However sometimes the rear plunger does not have enough tension to really hold the latch in position during cycling.

Remington’s solution was to drop a #7 ½ lead shot pellet into this rear plunger hole before you put the spring in. This increased the tension & improved operation.   Many of the 742 parts are now obsolete, this plunger being one, so if you make a new plunger out of .087 dia. drill rod, make it .280 overall length & you will have done the same as installing the lead shot as a spacer under the spring.   You may well try the spring & your new plunger in the assembled unit before you install them in the firearm, as if there is any debris in the hole or a slightly short hole, the latch may not be depressed far enough to allow the bolt carrier to depress the latch far enough, so you may have to shorten it.   Or if it is one that the factory or a gunsmith who attended one of the last seminars where this tidbit of information was passed on, the hole may be shorter already & it may be hard to get the lead shot out without drilling.

The first thing I would look at if a feeding problem seems to be the culprit, is the magazine. Feeding problems on these series of models can many times be traced to the magazine as with any semi-auto.   Here the average hunter is more likely to leave the magazine loaded even when the gun is put away.   Also the magazines will have been carried in a pocket where lint, twigs, dirt etc. can accumulate.   With this debris internally the live round can be restricted as it tries to feed up into the chamber, possibly causing a malfunction.   Also they can have became sat on & squashed so as to not allow the follower to come all the way up. You notice I do not use the word “Jam”, as it is so broad a term that it is essentially useless.

The followers from these semi-auto magazines will tax your imagination & patience to remove & then reconnect them back onto the trip latch.   I would suggest that to clean the internal parts of one of these, that either you soak it in solvent & blow it out with compressed air at the same time depressing the follower.   Or if you do disassemble one to get it clean, pay close attention to how it came apart.

The next to look at would be are reloads being used?   Reloads are not bad, BUT the reloader needs to be WELL aware of proper sizing for semi-autos. This is completely different than for bolt action guns.   A small base die needs to be used that sizes the WHOLE body back to original factory specs.   Also if a crimp is used on the case, it will have to be trimmed accordingly so there is no bulge at the neck.   This reloaded case MUST fall into the chamber.   Also it is advisable to only reload them to be used for hunting 2 or maybe 3 times.   As with this small base resizing will work the base & can create a case head separation of the brass after a few loadings.   You can reload them more, but use these multi loaded ones for target practice.   Believe me it is rather helpless seeing an animal you just hit, but did not go down & then run off with you holding a useless firearm.   You have a case head separation in your gun & about all you can do is to just can stand there with your finger in your nose.

Another thing to look at if you reload is that the pressure level has to be near the factory otherwise the bolt will not cycle enough to eject.   Read the reloading manual & try to pick a load at least in the mid range.

You guys that say I have reloaded for 30 years, therefore I know what I am doing does not mean a thing if it has NOT been for semi-autos that the reloader is in turn using themselves.    Hell, I have been eating for 70 years but that does not make me a cook.

Another problem with these guns is that the chambers tend to get rusty.   These extractors are a light metal "C" type clip with a small hole on one end that is used with a rivet to anchor it into the bolt head, & on the other side of this extractor there is a slight protrusion that has a sharp rear edge that acts as the extraction point.

At first the rusty chamber situation may just cause extraction problems.   Then since things do not improve by themselves, the extractor may get bent & not be as efficient as it should be.

As things worsen, the gun can malfunction by not pulling the case from the chamber because of the internal rust in the chamber gripping the fired case & or the faulty extractor.   If the rust job gets bad enough & the case is really stuck, the bolt will come back with enough force that it can rip the lips of the bolt face off.   This then leaves no metal to hold the extractor into the bolt head.   You now can have a really stuck fired case & a broken bolt head.

In the pictures below the barrel was almost ruined by neglect. The bore was bad also when I got the gun, but it was firing & extracting, much to my dismay. I was able to salvage this gun, by polishing the chamber with crocus cloth & fire lapping the bore, & the gun is still in service today.

A GOOD gunsmith/welder can weld the broken lips of the bolt & re-machine it back & reinstall a new extractor. If the chamber rust is not too bad it can be polished out with fine emery cloth wound around a slotted flexible shaft mounted in a 1/4" drill motor. It has been discussed on some message boards to not do this because it will change the headspace. Well, the gun is somewhat ruined now, whatever you do to get it operational makes it better than it was. Sure you may have made a slight change in the chamber, but using this method, you can not remove an excess amount. Also do not believe the BS about the chamber has to be slightly rough. Look at any new semi-auto & you will see a very smooth chamber. If it is somewhat rough, the extractor will indeed pull chunks off the case rim leaving the fired case in the chamber OR rip the bolt lips off that hold the extractor in place in the bolt. The roughness idea may have come from a retarded blowback pistol, which this is the case there, NOT HERE.

After many years of pondering why these guns were plagued with this phenomena & not the makes or models of others, the following answer finally came to me. It was the dedicated, hunt in the cold/rain, deer/elk hunters that seemed to have the majority of the problems. The sunshine hunters appear to not have any problems.

In the Pacific Northwest, elk season is later in the year when the weather is nasty, cold, rain, sleet & blowing. Also here the brush, replanted trees, & timber is thick, so the hunters usually get out in the brush in the morning, get wet & cold, and then drive around on logging roads in the afternoon to dry out & hope to see animals that some other hunters have put on the move. In the state of Washington, a loaded firearm in the vehicle is illegal, so they unload the gun, remove the magazine, & rest the muzzle on the floor possibly between the 2 hunters or in a gun rack for quick access.

This could also happen in a very humid climate. In the colder weather the barrel will condense water on the inside & since the action is spring loaded and has no means of being held open without an empty magazine inserted, the average owner simply leaves it closed. The gun has gotten wet & COLD, now it is subject to a forced HOT air from the heater, in this close proximity to heat, the COLD steel condenses moisture on both sides of the steel. With the bolt forward under spring pressure & the muzzle down, when the barrel warms up the inside has condensation, this rises & is trapped inside the chamber. But the inside has no place to go.

If the drive home is long enough &/or the firearm stays there long enough, the outside condensation will dry off. At the end of the day, he then takes it home & may stand it in the corner to dry off.   The condensed water inside of the barrel, then runs down & collects in the chamber area.   Then possibly the gun MAY see an oily cleaning patch run thru the bore but the chamber is usually missed.   This is not an area that the average hunter will even see if he runs a cleaning rag thru the barrel.   Usually the bolts are closed on most firearms when being stored.   This also traps any moisture inside the chamber.   The gun is set away with the bolt closed until the next year with the owner thinking that they have done the right thing.   The end result is a RUSTY chamber that we have seen MANY times, but did not understand what may have happened.

One of the most common problems with the Remington 740 & 742 is that after much use the receiver rails will get worn.   These rails guide the bolt lugs on the movement both rearward & forward.   The receiver is made of a soft metal since the bolt lugs engage the rear of the barrel for a positive lockup. The receiver simply holds the parts together.

This movement is under gas pressure on the rearward movement & spring pressure on the forward movement.   At the rearward stop position the inertia of this bolt lug exerts extra pressure caming it against the receiver rails, pounding them enough that they get worn.   There is a bolt latch on the 742 (this latch was not on the 740), this latch is supposed to lock the bolt head into the bolt carrier to help keep the front from over-rotating at the most rearward inertia's movement, but after wear on all parts, things seem to get sloppy & do not function as intended.

When this happens the bolt lugs, now slightly out of time, having been moving back & forth, may also chew up the front of the rails.   Then the bolt carrier & lugs can get bound up & in extreme circumstances actually stop the bolt unit from cycling when the gun is fired, or binding it on the return stroke enough to stop it before it completely closes.

Under some circumstances the operating handle may drag, usually on the bottom of the receiver slot that the handle operates in.   If this happens it is usually related to the above rail problem.

Since there are no new receivers available & the only used ones could be questionable in that may possibly be worn also, A GOOD gunsmith/welder/machinist familiar with firearms can usually salvage the receiver by welding the worn rails with a special long nozzled wire feed or heliarc welder.   This receiver can then be re-machined to factory or tighter dimensions on a vertical mill using special long cutters.   This is not a job for the average "gunsmith" however.

If you have to take the barrel extension of to do any rechambering or rebarreling you will need to make a barrel extension wrench. This extension is actually the barrels locking lugs. It is threaded & timed to the barrel so that the extension is indexed so the sights, barrel lug are all indexed for bolt lockup, headspace & everything where it should be. There is not any commercially available fixtures available to remove these extensions. If you try to use any other method, you will about 99% be assured of breaking the extension. However here is a picture of the one I made.

In the above photo, the inner slider is made to fit inside the barrel locking lugs. The 3/8" bolt locks the slider to the base. The bolt hole is also aligned with the barrel lug attachment bolt hole. In use, for removal the base is inserted over the barrel lug extension & the slider is then slid endwise into the lug recess. The bolt is inserted in just far enough to lock these 2 parts together, but not into the main barrel lug. Mark the relationship of the barrel to the barrel lug with a scribe mark on layout die. This will allow you to reinstall it in the same position.

Now Remington changed the threads at barrel date code (LO) from RH to LH to facilitate the extension not being backed off when used on the semi-auto guns. This will determine which direction, you trey to remove it from. You can nor put the barrel in a barrel vise, rap the removal handle in the proper direction & unscrew the extension off the barrel. They are usually on tight & require force to remove even after the initial bond is broken. Once it is off, if the barrel lug is stubborn & resists, you may screw the extension back on part way & do it over again but with the 3/8" bolt thru the lug & take both off at the same time.

The picture below of a fired 30-06 Winchester factory round that was fired in a early 742, barrel code (CM) that the RH threaded barrel extension had became loose & unthreaded as the case was being extracted. As luck would have it, the bullet exited the barrel in time to relieve pressure while the case was still somewhat in the chamber. You may notice a slight crease in the body behind the shoulder where this case upon being ejected was dented by the ejection port.

Remington has also discontinued making extractors for these guns, #14669 which was 30-06 size riveted type & are the same that had been used on the 700, 740, 742, 760, 788. These extractors are riveted into the bolt & require a special rivet & tool to install. They however are currently available from Brownells in Iowa 1-800-471-0015.

Bolt latches are also factory discontinued, but are being currently made by Wisner's Inc. Bolt heads are non existent, except from cannibalized guns, but by the time a gun has enough worn parts to warrant cannibalization, they too are usually worn or broken.

Magazine latches are also obsolete. However the latch off the newer 7400 series can be used if the new spring is also used.

Firing pins also are obsolete, however I think Pennsylvania Gun Parts is having them made.

Aftermarket manufacturers like Uncle Mikes make sling swivel kits to fit these guns.

Buttstock wood is the same for all of the models 740, 742, #4, #6, 74, 7400, 7600. The factory will not tell you this, but they will all interchange.   The finish or checkering may not match your original one however.   But at this stage of the game, you will more than likely have to take what you can find.

Forearms are a different matter.   All 740, 742 forearms are now obsolete, however if you replace the complete forearm, front metal plate & spacer, & the screw, then the current 7400 will fit.

Sights have changed many times over the years. If yours is one of the early guns (740) with a 3/8" dovetail, any aftermarket 3/8" sight, both front & rear will fit.   If your barrel has the sights screwed onto it like the 742s, & you loose part of the rear sight, you might be best to try to get a whole new one for the 7400 or even the 700 series, as the screw holes are all the same spacing.   The rear screw on sight has been changed 3 times & parts for the early versions are no longer available from the factory.

About all the newer type pump & semi-auto guns, be they rimfire, centerfire or shotgun use many of the same “Fire Control” (as Remington calls the trigger group) parts. This would be the 552, 572, for the RF, 740, 742, 760, 4, 6, 74, 76 7400 & 7600 for the CF. 11-48, Sportsman 48, 870, 58, 878, 1100, & the 11-87 in the shotguns. They are only supplied in Right Hand from the factory. You can not simply reverse the RH to make it function as a LH unit.

For many years there were aftermarket Left Hand replacement triggers available from sources like Williams Gunsight Co., Uncle Mikes, Herters, etc. However for some reason these companies dropped production. The guess is that if THEY sold you a replacement safety & YOU installed it improperly, that they were responsible legally because they SHOULD HAVE KNOWN that someone could also done something else wrong inside the “Fire Control” unit at the same time, creating a unsafe situation These companies also felt threatened by lawyers to the effect that they were making a product that altered the factory design.

You might find some enterprising machine shop that may possibly be making some LH safeties, but in all probability they too, would not be advertising it to any degree, because of the possible liability involved.

Early on, Remington supplied some of the trigger guard units drilled with 2 different safety plunger detent holes so that YOU could simply interchange the RH to LH. They even supplied a detailed drawing of this placement of the hole so gunsmiths could do it. However they found that beings as how this TG was made of a aluminum casting, that over time the THIN web between the 2 holes was prone to breaking & then the safety would not function as designed. More liability, so this whole idea was apparently abandoned.

Failure to eject after a scope was mounted is a situation that can also be encountered. The usual problem here is that the scope base mounting screws may be too long & dragging on the bolt lugs upon firing.

The factory has no cross-reference to the 742 parts interchangeability, & if a gunsmith orders the 742 part number, the order will come back saying -- discontinued--. This is very hard to understand in this computer day & age, but the factory service department underwent a total restructuring & moved to the southern US. The old people who knew anything were let go, so the new people either do not know or were told to not offer information that some of the new parts will fit. It is the belief that the factory does not want 740 & 742's repaired & therefore the above information seems to be more valid. They want you to by a new model.

There was a factory upgrade at one time, where you sent your non-repairable 740 or 742 back to the factory, that they would exchange it for a new 7400 for the wholesale price. This however was more than the original gun was worth even in excellent shape. This program has now been discontinued.

The factory even can not cross-reference the buttstock bolts, saying the older ones are obsolete. The 870, 7400/7600 stock bolts will fit.

For Remington factory date codes CLICK HERE

It seems that old guns are like many of us, in that just don't know when to give up. Sometimes however it is better to just let the old gun die.

Model 4 / 7400: There may have been some confusion with the other Remington #4, which was a Rolling Block single shot rimfire rifle that Remington made from 1890 to 1933.

When Remington dropped the 742, in 1981 they came out in 1982 with the newer internal design semi-auto, while still maintaining the same exterior configuration. It was designated model 4, & the model 7400. The calibers available were 6mm Rem. (discontinued in 1987) 243, 270, 280, 30-06, 308, & 35 Whelen. A carbine in 30-06 was introduced in 1988. The extractor was changed from the riveted in style, common with the 740, 742 & the bolt action 700 to a non-riveted snap in type. This new style extractor was also incorporated into the model 700 bolt action gun. But the 4/7400 utilized a slightly heavier/stronger version than the bolt action guns.

The model 4 was the deluxe version (or as the earlier 742 was designated, it would have been equal to a BDL grade).   The model 4 had high gloss checkered walnut wood with white line spacers under the buttplate, grip cap & forearm tip.   The model 7400 which was the same gun, except plainer wood, satin finish & pressed checkering (would have been equivalent to the ADL).

In the spring of 1982 the Remington factory sales reps told us (independent dealers) that "they" were advertising for the independent dealer & promoting the model 4 in all national magazines.   They did not tell us that there was also being made an economy model 7400.   We found out later in the early fall after we got our shipment of model 4s, that Remington had sold the 7400s to K-Mart, Wal-Mart etc. at a greatly reduced price as compared to the Model 4 that they were selling us.   The retail customer was not dumb, as he could buy a new Remington semi-automatic 30-06 from the "marts" for $100 less, he did not care what it looked like, only the price, & was discontent that we could not match their (the Marts) discounted price for our higher grade guns.   The situation was that the "marts" ordered only the 30-06 calibers, & the customer could not understand why we could not sell them a 270 Winc. for the same price the marts wanted for their 30-06.   We were therefore stuck with higher priced guns on our shelves.

Then in 1983 Remington acknowledged & then had the 7400s in their catalog & independent shop owners had to then buy the model 7400's to stay even somewhat competitive.   So the model 4's sat on our shelves & at the factory warehouse.   It took the factory a few years to figure out what was going on.

As time went on, new versions appeared including synthetic stocked models with glass-beaded dull metal finish & even a Electoless nickel finish on the metal.

Model 74: Then later, about 1985 there was an even cheaper model, the Model 74 made in 30-06 only, which took the place of the then "older" 7400, but with cheaper walnut stained birch wood & no checkering. The metal finish did not have the higher luster of the 7400. Now the "marts" could under-price us again because we did not know about these 74s. These guns also carried Remington's economy name of "Sportsman".

In 1987 Remington then phased out the model 4, & soon the Model 7400 started showing up with the better wood of the Model 4. So in essence the two above guns are the same except the wood & period of manufacture.

Magazines for the 740, 742, model 4, 7400, 74 are all the same & are interchangeable.

The models 4,74,7400 were designed with 3 larger locking lugs, a slightly cone shaped barrel breech for better feeding & a hardened rail insert in the top of the receiver to guide the upper locking lug, eliminating the possibility of the receiver rails being ruined. The scope base mounting holes were changed & increased in size from the normal 6-48 to 8-40 size. The firing pin was redesigned. The trigger group remained basically the same with the exception of a larger magazine release button.

About 2002 the magazine tooling wore out & there was only one company that was able, or wanted to do the deep drawing required for this operation. And they opted not to continue making the magazines. Remington then had MecGar make new replacement magazines out of 2 pieces with the bottom of nylon attached to the sides instead of a single drawn magazine.

Model 750: The year 2006 saw the model 750 replacing the wood-stocked model 7400 versions and features a restyled American walnut fore-end and stock with machine-cut checkering. Felt recoil is diminished by its ultra-efficient gas action and the addition of a revolutionary R3® recoil pad. It comes supplied with factory sling swivel studs.

It is supposed to have a better self-compensating gas system. But I can not believe that if both models are being produced that there would be any difference in the gas system. Maybe they just chrome plated parts of the 7400 gas system & are calling it improved. I believe the factory is simply pumping up sales information currently used on the 7400 gun. This model appears to me to be a regeneration of the earlier model 4 as a deluxe model.

A 7400 with a rusty chamber	Obviously someone used this one in a rainstorm & neglected to clean it