Sig CG Rifle failure to eject

C

canadianshooter

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I recently bought a Sig Classic Green. Took it to the the range and did a slow careful barrel break in. Then took it to the range for some rapid fire practice to see how it runs. In the three times I've had it to the range since break in, I've had a failure to eject each time (three times total). Pretty much a stove pipe in each case. Anyone else have this problem with such regularity? This is over the space of maybe 300 rounds. 3000 dollar rifle...... Thanks in advance for the help. Ammo was AE 55 gr. FMJ.
 
Make sure your rifle is clean and all of the original packing grease is out of it.

My Classic Green has between 8 and 9 thousand through it with one malfunction. (All kinds of ammo as well as reloads.)
My issue SG552 has over 4 thousand through it in semi, burst and full-auto with no malfunctions (using weird frangible ammo for practice that doesn't even look like a real bullet).

Our other SG552 and CQB have sightly lower round counts with no malfunctions.

Jams are very rare in my experiences with Swiss Arms (and HK) guns that we issue.

Rich
 
O ya,
Refenence the gas valve,
The test SG552 we used ran perfectly on both gas valve settings. Full auto / burst and whatever ammo we tried.

Rich
 
Check to see if the rifle has been over lubed, especially for our cold weather. If that isn't it, check to see where the gas valve is set. Might need to open it up a little.
 
clean and lubed and vertical

I religiously cleaned all of the factory grease out of the rifle before I shot it, then I lubed it moderately heavy with Break Free, including the piston head. Between each shooting I cleaned it very thoroughly and lubed it as well. Gas valve was always in the vertical position. After firing, the gas piston head is always heavily crusted with carbon and the gas valve has to be pulled off with some force, is this normal? I appreciate everyone's input here.
 
I often have to twist the gas plug out of the front of the rifle with som sort of tool, as the carbon has "locked" it onto the piston head.

That said, mine has only about 2000 rounds through it, but hasn't hiccupped once, with any ammo.... yet!

What's your extractor look like? Maybe the tip is broken or something?

Neal
 
As can be expected the piston head will be prone to residue build-up, and the valve will need to some "slight" force to remove it... which is perfectly normal.

Refer to the link for the manual:
http://www.sigarms.com/CustomerService/documents/SG550551OM.pdf

As stated in the manual Page 30:

The gas valve should ONLY be in position 2 when ejection or cycling problems occur as a result of a fouled (Meaning piston is heavily fouled and requires extra force to de-foul it) or iced weapon. This is an exception and should be immediately returned to position 1 once weapon resumes normal operation.. Shooting with valve in position 2 under normal conditions will add unnecessary stresses to the weapon.

See Page 9 (figure 4):

If the Bolt Head is under lubricated or using a lubrication that is affected by the temperature, this will also cause ejection problems; it’s best to use the light oil included in the kit to "lightly" lube this slide mechanism. Be sure to thoroughly rotate and slide the Bolt Head inside the bolt Carrier to ensure even distribution of lube throughout the entire contact area.

See Page 10 (figure 5):

Also ensure the Cam "raceway" is also "lightly" lubricated; I prefer to use white grease in the raceway.

I have personally had a run of ejection problems and traced the cause back to these two sources. Since then I have adjusted my lubrication "protocol" and have not encountered any problems.

Hope this helps!!
 
canadianshooter said:
then I lubed it moderately heavy with Break Free, including the piston head. Gas valve was always in the vertical position. After firing, the gas piston head is always heavily crusted with carbon and the gas valve has to be pulled off with some force, is this normal?
Click to expand...

Gas affected parts should be free of oil. Try cleaning the carbon off, oil it for storage, and wipe it dry before shooting.
 
Lube maybe

I'll definitely pay more attention to the lube though I'm wondering how sensitive it could possibly be. Generally my rifle is clean and lightly lubed everywhere; though I'll stop shooting with the piston head lubed as that definitely makes sense. I'll also take a closer look at the ejector. Another thing I forgot to mention is that after firing there are brass "filings" around the chamber throat. After ~100 rounds there is quite a bit of fine brass bits in the receiver, is this normal? Not sure what could cause that. Thanks for all the info.
 
canadianshooter said:
I'll definitely pay more attention to the lube though I'm wondering how sensitive it could possibly be. Generally my rifle is clean and lightly lubed everywhere; though I'll stop shooting with the piston head lubed as that definitely makes sense. I'll also take a closer look at the ejector. Another thing I forgot to mention is that after firing there are brass "filings" around the chamber throat. After ~100 rounds there is quite a bit of fine brass bits in the receiver, is this normal? Not sure what could cause that. Thanks for all the info.
Click to expand...

Yes the brass filings are quite normal, as you've noticed the extraction is alittle rough on the brass casings.:)
 
A good friend of mine is having the same problem with his scout length model. Every few rounds the casing looks like it bounces back in. The casings are kicked out fairly inconsistently. A new round is stripped and ready for chambering but the casing is either stovepiped or completely reversed in the ejection port. We have tried playing with the gas system and even swapping various parts and combinations thereof from his full length model. Still giving him greif. He has had the rifle for a few years but has only resently started shooting it, so taking it back might be a problem. I have never played with these before but for $3000+ they are not impressing me. Yes I know I have only seen this with the one rifle, but now I've heard of another. Sorry if I come across as being critical. Anyway, just thought I'd add my experience as well.
 
same issue with me

Your friends problem sounds identical to mine. Sometimes the spent brass is entirely reversed or stovepiped. I think having it looked at professionally may be the best bet. I'll give it one last try but I'm a bit worried about reliability now. Thanks for the info.
 
greentips said:
Take it to the place you buy it from and have them sort you out.
Click to expand...

Sorry, this thread kind of bugs me, so I fixed your above statement, GT

Heavily lubing the gas piston tells me a shooter A) hasn't read the manual B) doesn't have experience with this operating system.

If someones lubed the hell out of the piston, have they put it back together correctly?:eek:

I've fed my PE-90 absolute crap ammo that wouldn't cycle in a bolt action never mind an AR or other semi...I find it extremely hard to believe that QC has fallen apart on this one...check all of the variables before you blame the rifle....
 
While I agree that lubing the gas system is not a great idea, I have had a few customers complain about an occassional case bouncing back into the action. Usually this type of failure is hard to trouble shoot because it is very infrequent. Several times it was traced to a barrier next to the shooter. If you feel your gun is unreliable, drop me a line and I'll replace it. I only ask that you eliminate the common issues, ammo, gas valve and a barricade on the right of the shooter, before sending it to us.
 
HOLY MOLY ... people have problems with their Sig rifles ... faarked up ... :confused: ... if you read the manual, follow instructions, I don't see how you could have any problems with these rifles ... and I've shot mine with all kinds of ammo in extreme cold weather, wet spring and fall weather, hot dusty summer days ... never had a hiccup ... :confused:

Otokiak
Rankin Inlet, NU
CANADA
 
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I and a club mate had similar problems with our 550 SP's. Spent cases would flip around inside the chamber. His rate of failure to eject was around one in thirty, mine around one in two hundred, others that bought 550's in the same shiipment have had not a problem and are running clean for thousands of rounds. The clubmate had put same tape to stop the spent cases marking the rifle for which the shop said was the cause of the failures, we kind of blinked and said "huh?", in the end they refunded the purchase price. I kept mine as I prefer shooting service match with it over my AR.
 
Put together right, manual read,

I think I should mention that I have read the manual carefully and that I wasn't HEAVILY lubing the gas piston, unless wiping it down with a patch wet with Break Free is heavily lubed. However I wasn't wiping it dry before shooting it. I'll take it to the range and give her another run with a dry piston. Also no barricade nearby when cases stayed in the chamber. The design also makes this rifle hard to put together wrong, no way that I can see (or have you found a way to put it together wrong the hard way?) Finally in section 4.2.6 of the manual it says to "lightly oil the gas piston and recoil spring" - I find it hard to believe that I oiled it so far beyond this point that I'm causing malfunctions (I do read manuals). Thanks to Redleg for taking an interest in this - I'll try to eliminate everything before I send it back.
 
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