Repairing a 742

[MTT TL]

- Is there a practical way to repair the locking rings on a Remington 742?

- There are some missing and worn away. This does not appear to effect accuracy or reliability, are there any other issues with badly worn down or missing locking lugs?

 

[Goatwhiskers]

What are you referring to as locking rings? I assume that you refer to the lugs on the bolt with matching lugs inside the barrel extension. I can think of no reason why any of them would break off unless you or someone has been shooting HOT loads, which is an absolutely insane thing to do with gas operated weapons. At any rate, I suggest that you scrap the gun, as finding a bolt is chancy at best, and it should be headspaced as any other gun, which is a whole new ball game on the 742. The gun is definitely UNSAFE to fire in its present condition. Goatwhiskers the Elder

 

[oneoldsap]

Sounds like it's time to turn that Jam-O-Matic into a lamp ! If the barrel isn't shot out you could probably sell it and the stocks .

 

[James K]

Before you go scrapping that rifle, I suggest a closer look and maybe checking with a gunsmith. Some of what look like lug positions don't have lugs for very good reasons.

But should it be needed, you can replace the bolt head, though I suggest that be done by a gunsmith or better yet by Remington due to headspace considerations.

Jim

 

[Hog Buster]

Unfortunately for you I have to agree with Goatwhiskers and oneoldsap, scrap it. While it might be able to be rebuilt, it’s kinda like a Yugo. It wasn’t to good new and rebuilding it ain’t gonna help. It will only empty your pockets of bucks.

 

[lefteyedom]

742. worth fixing

The 742 is worth fixing if you are attached it. If it's just a rifle you picked up at a gun show then think hard about what you are willing to spend on it. I have my father's 742 Woodmaster 30-06 and will have it till I died, so money would not be an issue.

The thing to remember about the 740, 742, 7400 rifles is that they are not Military grade rifles. They are deer rifles meant to be sighted in and then shot 3 to 5 rounds a year. In this role they are just fine. Untold numbers of whitetail have fallen before these guns.

The 742 had problems but it was not as bad as it is made out to be online. Most (but not all) of the problems were related to poor maintenance.

One major problem is finding a gunsmith that both knows what he is doing and is willing to work on them. Out here in Wyoming one almost never see a 742 or 7400. Back east they are far more common and therefore you are more likely to find someone willing and able to work on it. It is my understanding the Remington no longer will repair the 740-742. The other issue is just finding parts for them...

http://www.ahlmans.com/riflework.html

Ahlmans will converting your semi-auto 742 to Pump action 760 for about $230.00

 

[MTT TL]

Yep, talking about the locking lugs inside the receiver where the bolt engages. There is only one full one left on the receiver and half another one.

Far as I know there were no hot loads fired in it. I bought it for under $250 about ten years ago and have put about 300 rounds down range with it since.

Have not shot it in about 3-4 years until I brought it out the other day and put some Greek down range with it. It does not jam so far as I can tell so long as it is clean.

Just curious as to why it is unsafe? I put about 50 rounds down range with no problem the other day.

 

[Goatwhiskers]

Why is it unsafe? Because when the last of the lugs let go there is no telling where the bolt is gonna go and I wouldn't want to be standing beside or behind the gun when it does. Here endeth the lesson. Goatwhiskers the Elder

 

[James K]

"Yep, talking about the locking lugs inside the receiver where the bolt engages. There is only one full one left on the receiver and half another one."

Huh? The bolt on the 742 doesn't lock into the receiver, it locks directly into the barrel; there are no locking lugs in the receiver.

Jim

 

[kirbythegunsmith]

Details

This situation requires pictures of the area in question to eliminate the armchair guesses being thrown about that are nothing more than suppositions base upon incomplete information.

If a litany of possibilities exists, don't try to over-diagnose an issue that may be the complete opposite of what was discerned due to insufficient knowledge of the owner.

The 740/742 have similarities of problems and are off the factory list of in-house repairs due to obsolescence and lack of parts remaining.

The 7400,
Model 4
and 750
all have the more advanced multi-lug system that has large individual locking lugs rather than a row of multi-lugs in several rows, so

don't include them in any critique of the 742 style system.
Those guns have much better longevity inbuilt, but any semi-rifle is going to be more sensitive to conditions and maintenance, so for these specific mechanisms, I recommend a thorough gunsmithing service about every 5-7 years or so- if used in typical service. Heavy and extended use may require service sooner; exposure to heavy rain and other severe conditions or malfunction of operation all point to an immediate service session.

------------------------------------
It makes me think that anyone doubting the safety of a gun and then going to the range to send multiple shells downrange is either not very careful or not really doubting the gun.
------------------------------------

Is there another possibility that I may have missed?
I'm not trying to be flippant, but there is ample reason to be extra careful with high-pressure mechanisms, and the modern rifle is at the peak of containment compared to almost any other invention.

Kirby

I do a fair amount of rework to 742 style actions and the more modern versions previously mentioned.

 

[MTT TL]

It makes me think that anyone doubting the safety of a gun and then going to the range to send multiple shells downrange is either not very careful or not really doubting the gun.

Pretty much, especially now. And thanks for your more knowledgeable, less-confrontational answer.

Anyhow, I did not notice the problem until I got back from the range and really would not have noticed them missing at all if I had not been looking at my sons 7400 which has similar rings of course. That is what got me to wondering about it.

I think I found the answer I was looking for anyway though. Don't know who this guy is but he seems pretty knowledgeable:

http://www.wisnersinc.com/additional_info/Remington_7407427400.htm

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.

So, one of the most common problems with the model due to wear and tear and not due to shooting hot loads.

On the receiver, not the barrel, at least on mine and others anyway.

The actual danger would be the gun firing slightly out of battery with the case not being fully supported... that could cause some problems. I can't see how the bolt would go flying off since it is a SA action designed to cycle. It might beat the action to death over time but seems in no danger of giving way.

Since the solution requires machining it sounds like it is beyond the price range I want to spend, and likely that of the skills of most gun smiths. Certainly any I know.

So the answer to my question is no, likely not.

Here endeth the lesson. Goatwhiskers the Elder

Yep

 

[jaguarxk120]

Listen to what Kirby is telling you, before you or someone else gets hurt.

 

[kirbythegunsmith]

Details

You are correct that there is some similarity to the later 7400 and 742, but just as a Neanderthal and Human have similarities, doesn't mean we can equate one feature to the other species, as it were.

I still would like to see pictures of the area in question that give a clear indication of your situation.

Since you did find that prevailing idea used by some to weld the frame etc in a costly manner, it might be possible to understand that there is more than one way to improve the situation- and one that doesn't require welding might be seen as a viable and more clean result that doesn't require external polish/blue to look acceptable to the eye.

I have made such repairs to these mechanisms that eliminate the bolt jamming and negate the justification for welding/machining.

Funny that over at another thread, there are postings that make them leery of the idea of frame welding.

I will weld and rework frames in situations that have no other solution, but this is not one of them.

Guess it depends on whose defective condition is being discussed.

Kirby

 

[MTT TL]

Thanks, but I will not be able to post pics until July. I may do so then.