I just got an awesome rem 742 bdl in 308 Winchester .It is perfict except for the bolt dust cover is missing and I need to know how to replace it .I also saw a new style easy to use mag release I forgot g
How to put those on. Also how do you clean the gas port .This is a beautiful looking gun shoukd be fun to shoot just needs a little extra stuff .

you have to pull the barrel, and slide the bolt assembly forward out of the front of the receiver to put the dust cover on, then slide it all back together

I've replaced the dust cover on my 7400 a few times. Should be the same as the 742? With use a crack will develop in the dust cover. It's flexible so I managed to install it without disassembling the rifle. Easy, takes a few seconds.

I was afraid of that
dang a bunch of trouble for a
Little plastic piece .I know I need it on there to keep trash out .I hope that new style mag release is way better and alot easier .What other parts should I replace when I take it apart .

I first recommend you shoot it to test function before tearing it down. That way you have a starting point. My experience with these guns is "if they ain't broke don't fix them". You can take it apart and open up a whole can of worms.

The gas port is accessed after the barrel is removed. There is a staked set screw on the gas block that has a ball bearing valve under it. Remove and use a fine soft wire to clean out the gas port through the gas tube and gas orifice.

While you have the barrel off give it a good cleaning and polish the chamber.

Check the receiver raceways for chatter marks which indicate wear on the bolt cam pins.

Mag releases are simple drop-ins. Just have to manipulate the spring.

"You can take it apart and open up a whole can of worms",,,, no truer words have been said! Maybe Bobster knows, but the current made dust covers from Remington shows the cover fitting only the Model 4 and Model 7400, not listing the 742 which has long been obsolete.

Brownells has dust covers for the 742. It helps to have 3 hands when lining everything up during reassembly.

Just don't low crawl through the mud and you will be fine. Most semi autos do not have dust covers anyway.
Or cover the opening with tape.

Indeed, I was remiss. The gun has been declared obsolete by Remington and there are few parts for them. Numrich bought most of the spares. I think I may have a cover in the shop but again, as DCPD stated, you really don't need it. After all the venerable civilian BAR doesn't have a dust cover. The Garand, Military BAR, and M1 Carbines didn't have one either and they fought a war. Our shop owner now refuses to accept them for work.

There can be numerous issues with these guns related to feeding and cycling. Factory loads have changed several times since these were introduced. Loads from the 1970's that cycled perfectly don't exist anymore. New powders, bullets and such. Pressure curves change. We've had to drill out gas ports, shorten action springs, install stronger action springs, replace worn cam pins, and reshape raceways to get them to work. Sometimes we could get them to work reliably with only one load. Feeding issues abound related to changes in magazines, worn latches, and timing because of aforementioned problems. Most of the time they exist simultaneously. I've had to put over 100 factory test rounds through one to certify a fix. 100 rds of ammo at $25 a box adds up. Plus spend 16-20 shop hours on the gun. The fix rapidly mounts up to far more than the gun is worth.

My advise is this: if the thing shoots OK, to clean carefully from the muzzle with a muzzle protector and get a Garand or M14 chamber brush to keep the crud out of there. Keep a dab of grease on the internal receiver rails too.

quote:

Originally posted by slivers:
"You can take it apart and open up a whole can of worms",,,, no truer words have been said! Maybe Bobster knows, but the current made dust covers from Remington shows the cover fitting only the Model 4 and Model 7400, not listing the 742 which has long been obsolete.

I won't work on 'um, either. They can be repaired but as Bobster says, "you can quickly put more into it than what the gun is worth". If I remember correctly, the extractor is riveted in, and new ones don't exist anymore. And no, a riveted extractor for a 700 won't work. It doesn't end up in the proper position on the bolt face. About the only semi auto I have much use for is an M1A or a M1.

No reason or need to clean the gas port; if 50,000 psi doesn’t clean it nothing else will.

You need to check the port and orifices on an unknown gun so you can tell if the system has been altered. Our shop has received guns with loose valve screws and altered orifices. I have encountered guns with fouled orifices.

quote:

Originally posted by Toomany Tools:
No reason or need to clean the gas port; if 50,000 psi doesn’t clean it nothing else will.

Checking it for tampering would be prudent if the is a serious over-speed problem, but cleaning it is a waste of time.

Almost forgot:

I guess the bdl reciver is almost the same as the adl receiver .There is a slight rise in the receiver of the bdl .It looks fine except for the dust cover missing .The helper seems to fall soft on the firing pen the spring might be weak .I will try to shoot it tommorow to see how she shoots .It sure is an awesome piece of wood on this bdl stock .