Co-worker is complaining of his 7400 jamming on occasion, though at times itll shoot several w/o jamming. After looking at the rifle, lubing with some Militec, cleaning barrel, running Kroil and Tri-Flow thru gas port and running dummy shells thru it several times, I couldnt find any reason why it would jam, afterall, it did eject the dummies very well. Now, why is it jamming with factory Remingtin shells? Any ideas? Jay

Jay,

The local gunsmith recommends that anyone wishing to hunt with the 7400 should have two of them. One to hunt with while the other one is in the shop getting fixed.

Jim

FWIW, Steve just picked up his rifle and he was saying the thing mainly jams when the loaded shell is going in, in fact, he showed me one such shell in his Remington ammo container, had a little ding about half way down the case. BTW, my 6mmRem. never had one jam in over 125 shots, most were my reloads, too. Dads 6mm 742 never jammed on him as well. Hopefuly Steve will have better luck with his '06 when he gets up north today. Jay

i have a 740 that i run dry. it never jams w/ spitzer bullets. i have yet to try round nose. back in the day when my dad got it from my grandfather it jamed all the time because they over lubed it.

This rifle was very dry when I looked at it, but, it was very smooth and didnt stick in any manner when manually cycling the action. Dont think I overlubed it when I dropped a few drops of Militec in the action.

Dad used a 740 and my oldest brother had a 742. Neither jammed and the only thing the action was ever lubed with was a very small amount of powdered graphite. There is about 65 years of hunting between those two rifles so I would suggest it is hard to argue with that logic. I have seen two things that will screw them up
#1 lube the action with oil or any kind of spray
# 2 drop the clip so the feed lips get bent.

Please dont take this the wrong way. The rifle jammed because it is a semi-auto. I have yet to see one that doesnt although everyone who has one says they dont. I think that of all the semi auto rifles and shotguns I have been around have jammed at one time or another. And please dont write back to tell me yours doesnt.I allready know, of course it doesnt!

quote:

Originally posted by snowman:
Dad used a 740 and my oldest brother had a 742. Neither jammed and the only thing the action was ever lubed with was a very small amount of powdered graphite. There is about 65 years of hunting between those two rifles so I would suggest it is hard to argue with that logic. I have seen two things that will screw them up
#1 lube the action with oil or any kind of spray
# 2 drop the clip so the feed lips get bent.

I always lubed my 7400 6mmRem with synthetic gun lube(a few drops on the parts that slide on one another), as did my dad with his 742 and neither ever jammed. As I said in my earlier post, I put over 125 shots thru mine testing my reloads, thing was a shooter for an auto, it would put 5 shots in an inch @100yds,(next year I sold it) only tried that once, but it did do it and I was quite surprised at that. Jay

quote:

Originally posted by bwest:
Please dont take this the wrong way. The rifle jammed because it is a semi-auto. I have yet to see one that doesnt although everyone who has one says they dont. I think that of all the semi auto rifles and shotguns I have been around have jammed at one time or another. And please dont write back to tell me yours doesnt.I allready know, of course it doesnt!

Definitely a baffling post. You don't even allow somebody to disagree with your statement . By the way I've had 2 BARs 1 cal 30-06 and 1 cal 300WM and I currently have a lightweight one cal. 300WM. I've shot at least 400 rounds with each, at the range and while hunting, almost all reloaded by me. I've had 0, ZERO jamming so far, but, of course, I'm a liar.

quote:

Originally posted by Jay Gorski:
FWIW, Steve just picked up his rifle and he was saying the thing mainly jams when the loaded shell is going in, ...

That is different than the jams most folks "occasionally" experience. Most of these occur simply because the Chamber has Trash in it from Cleaning.

As the Bore Brush moves into the Chamber from the muzzle, the bristles "spring forth" and toss Trash into the Chamber. The Patch just won't open wide enough to wipe the Trash out. So, the Chamber really needs to be cleaned through the Ejection Port. Hoppe's makes a "T-shaped" clening rod that has a flexable Nylon Shaft which is great for this style Action.

It is also of great benefit to designate one "Spent Case" to use in the Chamber when cleaning. That way most of the Trash goes "inside" that case. Just rinse it out later.
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Jamming on the way in, when being cycled by hand, sounds like the Feed Lip issue that "snowman" mentioned. Easy enough to find out buy buying one new magazine.

If that is it, just watch how the two Feed and adjust the old one's Release Timing by s-l-o-w-l-y reconturing those Feed Lips.

If he has another magazine, ask him to try it. If he doesn't, then he needs a spare anyhow.

Best of luck to your buddy.

HC, He's on his second magazine now, also had other buddies clean it out, Im hoping they cleaned the chamber out as I did, bought a new angled brush from Remington a couple years ago for cleaning autos. I cycled 4 dummy shells thru it several times, they all came in and out w/o flaw.

Was thinking about the way the unfired shell he showed me had that dent half way down the brass, figured it never caught the base of the shell as the bolt face was coming forward. But just how would that happen? Shell was canted upward in the mag? Highly unlikely, though possible, I suppose. He had mentioned he'd get fired shells jamming on the way out but wasnt sure how many and the frequency of that type of jam.

Hey Jay, Maybe the magazine spring is weak. Does this occur when the magazine is Fully Loaded?

Does it happen from both sides of the magazine?

Has he tried a different Lot of Factory ammo?
-----

Jamming on the way out is totally different from what is causing jamming on the way in, which I feel sure you all recognize.

If the Extractor is "Tearing Through" the Case Heads, it is a high probability there is Trash in the Chamber, or some kind of Burr which is holding onto the Case.
-----

He might have to "panic" and take it to a Gun Smith, but it can be fixed. The Remington Semi-Autos have their quirks, but normally seem to work real well.

He said the thing jams pretty much whenever it wants. Tried his uncles reloads with round nose bullets, they also jammed. As far as I know he hasnt used any other factory besides the Rem. brand. The magazine seemed pretty stout to me, on par with my 7400 when I still had it. The way the unfired shell looked, it seemed like the bolt was never catching the case head, so trash in the chamber would be moot point. Like the shell never got out of the mag. When I looked at the rifle, it was very clean, only thing I found was the bolt face a had a bit of gunk around the edges(inside), sprayed & brushed it, good as new.

Oh, and looking at a spent shell I noticed the primer was pitted, the most pitting ive ever seen on a spent primer.

One of the problems with the 742 and 7400 is the rails in the reciever that the bolt slides on wear out. As far as I know the rails can not be replaced with out replacing the reciever.

quote:

Originally posted by Jay Gorski:
......I cycled 4 dummy shells thru it several times, they all came in and out w/o flaw.

Was thinking about the way the unfired shell he showed me had that dent half way down the brass, figured it never caught the base of the shell as the bolt face was coming forward. But just how would that happen? Shell was canted upward in the mag? Highly unlikely, though possible, I suppose. He had mentioned he'd get fired shells jamming on the way out but wasnt sure how many and the frequency of that type of jam.

Hard to evaluate without seeing the rifle or the jams. It appears, if the bolt is catching the side of the case during feeding, either that the magazine is not lifting the case up quick enough; possible but not probable given the second magazine. The more likely is the bolt is not cycling completely back to pick up the next cartridge from the magazine and is digging into the side of the case. The other indication of this is the sometimes failure to eject.

I would check the gas system to ensure it is assembled correcly. I'd also try other ammuntion as you haven't mentioned what is being used. There is some rather anemic '06 ammo that does not have the port pressure the 7400 is designed for.

Larry Gibson

When I sprayed Tri-Flow into the gas port, I could clearly hear it run thru the system, U know, that hollow sound as the fluid is spray in the gas port.

Since he mentioned at times itll shoot several times w/o jamming would indicate the ammo he's using is anemic. I almost loaded some shells for him to try but dont really have extras laying around. He'll give me a full report on his return to work in a couple weeks. If it still jams, Ill suggest some new ammo other than Remington brand, or better yet, ask him if I can reload some that should be way better than factory fodder.Hmmmmmm, maybe a load of 50grs RE15 and a good 165 Hornady SP. Jay

Hey Jay, The next time it jams during loading, get a good look at where the Case is "on the Bolt Face".

And make sure the magazines are completely seated.

Can you reach a Q-Tip in and see if there is a Burr, Rust or Trash on the Bolt Face?

Definitely, ask him to leave it jammed until you can see it, if possible.

The magazine latch on these rifles, IIRC, is available in about 6 different lengths and must be selectively fitted to the individual receiver. If the bolt is overriding the top cartridge in the stack thereby causing the feed jam this is a likely place to look...

When I cycled the dummies thru it always caught the next shell, never ran on top of the shells or anything like that, did this dummy cycling about 7 times, all ejected and fed just as perfect as you can get. I mentioned to him to do the "tap the mag on the helmet" thing, to make sure the bullets are seated, said he always made sure the shells were back far enuf, but he didnt "Tap" them.

My son's rifle did the exact same thing. All the things listed so far were either tried or eliminated. In the end the problem turned out to be the magazine retaining system. When inserted the mag looked correct altho' in reality it was sitting a fraction lower than it was designed to be. This caused the bolt to override the case as it moved into battery and thus the ding in the brass about halfway up the case. In some instances it would grab the case near the head but past the rim pushing it forward but not allowing it to rise normally for entry into the chamber.

The gunsmith replaced the trigger assembly and we have not experienced any issues since.

Don't know if this is your problem just what we experienced, hope it helps.

SFC E7 (retired)

Of the fixes noted, SFC's has a lot going for it due to production tolerances. A bad magazine is always considered the first problem to look at, though. Have your friend try a BRAND NEW, FACTORY-PACKAGED, magazine. Next, check for burrs on the bolt, extractor, ejector, and back into the action to ensure there isn't a problem there. Clean out the back of the action so the bolt has full rearward travel. I was sent through the Remington training back in the late 60s and we went through 1100s and 742s for a few days. Mic McPhereson's book on working on factory rifles has some info on the 760-series pumps which are very similar (many interchangeable parts) to the 740-series guns.