m-1 garand & m-16 ejection problems

imti · February 11, 2001, 02:28 AM

can anyone tell me why my m-16 and m-1 garand fail to eject spent cases completely? all ammo is military fmj ball. fired cases remain held by the extractor and sometimes reinserted into the chamber or the case mouth butts up against outer right edge of the chamber . the ejector (plunger) spring tension seems ok. unfired rounds cycle thru the action smoothly and eject ok. all mainsprings are untouched and appear to be ok. but fire the guns and u have a single shot straight-pull magazine fed military classic. all clips & mags are new. the gas systems of all guns have been thoroughly cleaned of residue with no traces of oil/burnt powder to gum up the works.
the m-16 is the later issue with heavily ribbed front handguard.
my garand is a springfield armoury issue of ww-2 vintage minus the wooden forend that covers the rear of the gas cylinder and operating rod.
will greatly appreciate expert (and frustration/ammo saving) advice on the aforesaid from anyone-please!

Keith J · February 11, 2001, 02:51 AM

I realize the Garand might be a rebuild.
Both cases are short stroking, indicating not enough gas is present to operate the mechanism. On the Garand, it might be a worn piston. These are mendable but a 'smith will be necessary to rebuild it.

On the AR, check the gas rings. If they are lined up, the rifle will not work correctly and you will get the partial operation. If its new, it might just be a carrier key needing some seating shots to foul the gaps shut. The TM's state 7-10 rounds are necessary after replacing this part.
Also the gas tube could not be sealing.

If you are handy and careful, Permatex gasket sealing compound #2, applied carefully around the gas passages as to not gum up the works, will do wonders. Just a smeared, light coat on both surfaces (key and carrier) allowed to dry before assembly is all it takes. Loc-Tite the screws (red)or stake them IAW the TM. Some cruddy machining will leave gaps big enough to cause this problem. A little sealant fixes these errors.

This stuff also works on loose gas tubes. Partially assemble so that the gas tube is 1/8" short of alignment of the pin holes. dab a small bead all around the tube and slide it home. Install the pin and let dry for a day.

This will keep the gas tube around the front sight clean. Many AR's leak horribly here and will show gray residue after a few shots.

Cheapo · February 13, 2001, 01:03 AM

How about crud/burr(s) or a weak spring in the ejector plunger area?

Both use a spring-loaded bump thingie in the bolt to huck out the empties. If the spring hangs up, no ejection.

imti · February 18, 2001, 12:42 AM

Thanks to Keith J & Cheapo for your replies. Yes, the m16 & garand were short stroking. Both are old guns. The gas rings on the AR were not lined up but there were signs of leakage around the place where the carrier and key mate in spite of the screws being tight. Permatex sealant as mentioned isnt available here but I used a sealant meant for engine block and exhaust gaskets and it works.By the way, should the tail end of the bolt be a loose fit or should it fit exactly? I feel that there should'nt be any play in this area for gas to leak. The gas tube fit around the barrel front is ok.
The 'smiths hereabout are good only for crude work on single barrel break action shotguns and bolt rifles, so I have to manage as an amateur 'smith and the AR is the first I've come across. Thanks for the gen on the Garand - there is some slop fit between piston & cylinder which I will fix soon.
This is a great forum for fellows like me, because theres nobody here to toss ideas around with.
Thanks again.

Keith J · February 18, 2001, 01:52 AM

The tail piece of the AR15 bolt is a very close fit in the carrier. If you remove the gas rings, you can get a better idea of the clearances. Its sealing mechanism is just one of long bearing length and a close fit. It leaks greatly but I have never seen one that was worn to the point of inoperation.

There is nothing one can do to remedy this problem short of changing carriers. Check the tail piece for abnormal wear. If you see a ridge, its probably the bolt. If not, the carrier could be bad. I don't have access to the carrier drawings so I don't know what the correct diameter should be. I'll look around.

February 18, 2001, 12:42 AM	#4
imti Junior Member Join Date: October 21, 2000 Posts: 7	Thanks for the tips - end thread Thanks to Keith J & Cheapo for your replies. Yes, the m16 & garand were short stroking. Both are old guns. The gas rings on the AR were not lined up but there were signs of leakage around the place where the carrier and key mate in spite of the screws being tight. Permatex sealant as mentioned isnt available here but I used a sealant meant for engine block and exhaust gaskets and it works.By the way, should the tail end of the bolt be a loose fit or should it fit exactly? I feel that there should'nt be any play in this area for gas to leak. The gas tube fit around the barrel front is ok. The 'smiths hereabout are good only for crude work on single barrel break action shotguns and bolt rifles, so I have to manage as an amateur 'smith and the AR is the first I've come across. Thanks for the gen on the Garand - there is some slop fit between piston & cylinder which I will fix soon. This is a great forum for fellows like me, because theres nobody here to toss ideas around with. Thanks again.

February 18, 2001, 01:52 AM	#5
Keith J Senior Member Join Date: December 15, 2000 Posts: 469	AR 15 bolts etc... The tail piece of the AR15 bolt is a very close fit in the carrier. If you remove the gas rings, you can get a better idea of the clearances. Its sealing mechanism is just one of long bearing length and a close fit. It leaks greatly but I have never seen one that was worn to the point of inoperation. There is nothing one can do to remedy this problem short of changing carriers. Check the tail piece for abnormal wear. If you see a ridge, its probably the bolt. If not, the carrier could be bad. I don't have access to the carrier drawings so I don't know what the correct diameter should be. I'll look around.

February 11, 2001, 02:28 AM	#1
imti Junior Member Join Date: October 21, 2000 Posts: 7	can anyone tell me why my m-16 and m-1 garand fail to eject spent cases completely? all ammo is military fmj ball. fired cases remain held by the extractor and sometimes reinserted into the chamber or the case mouth butts up against outer right edge of the chamber . the ejector (plunger) spring tension seems ok. unfired rounds cycle thru the action smoothly and eject ok. all mainsprings are untouched and appear to be ok. but fire the guns and u have a single shot straight-pull magazine fed military classic. all clips & mags are new. the gas systems of all guns have been thoroughly cleaned of residue with no traces of oil/burnt powder to gum up the works. the m-16 is the later issue with heavily ribbed front handguard. my garand is a springfield armoury issue of ww-2 vintage minus the wooden forend that covers the rear of the gas cylinder and operating rod. will greatly appreciate expert (and frustration/ammo saving) advice on the aforesaid from anyone-please!

February 11, 2001, 02:51 AM	#2
Keith J Senior Member Join Date: December 15, 2000 Posts: 469	Are these new rifles? I realize the Garand might be a rebuild. Both cases are short stroking, indicating not enough gas is present to operate the mechanism. On the Garand, it might be a worn piston. These are mendable but a 'smith will be necessary to rebuild it. On the AR, check the gas rings. If they are lined up, the rifle will not work correctly and you will get the partial operation. If its new, it might just be a carrier key needing some seating shots to foul the gaps shut. The TM's state 7-10 rounds are necessary after replacing this part. Also the gas tube could not be sealing. If you are handy and careful, Permatex gasket sealing compound #2, applied carefully around the gas passages as to not gum up the works, will do wonders. Just a smeared, light coat on both surfaces (key and carrier) allowed to dry before assembly is all it takes. Loc-Tite the screws (red)or stake them IAW the TM. Some cruddy machining will leave gaps big enough to cause this problem. A little sealant fixes these errors. This stuff also works on loose gas tubes. Partially assemble so that the gas tube is 1/8" short of alignment of the pin holes. dab a small bead all around the tube and slide it home. Install the pin and let dry for a day. This will keep the gas tube around the front sight clean. Many AR's leak horribly here and will show gray residue after a few shots.

February 13, 2001, 01:03 AM	#3
Cheapo Senior Member Join Date: November 19, 1998 Posts: 986	How about crud/burr(s) or a weak spring in the ejector plunger area? Both use a spring-loaded bump thingie in the bolt to huck out the empties. If the spring hangs up, no ejection.