Century strikes again

[BISHOP]

And this time I'm the victom.

I bought one of their C93s and everything was all good and such (for about a month) until today, I shot it.

I got one good shot that shot and ejected and then after the second it all started to happen, and happen again.
Fail to fully eject and then trying to load another cartridge in with the empty.

What is really odd is what the shells look like.

Look at the pics, what will make the shell curl inward.
I even shot one steel cased shell just to make sure it wasn't the brass causing the problem.








What do you think?
Century will be getting an e-mail to see what they plan on doing with this problem of theirs.


BISHOP

[6gunsal]

I got one good shot that shot and ejected and then after the second it all started to happen, and happen again.
BISHOP

I was getting worried at this point. You were making it sound like it was slamfiring

[hi_capacity]

Wow, never saw anything like that before.

[davepool]

Damn, that looks dangerous, lots of gas blowback into the chamber.

[alismith]

Damn, that looks dangerous, lots of gas blowback into the chamber.

I agree. The scorch marks on the sides of the casings show that clearly, but could gas blowback have caused the lips to curl inwards, too?

Barrel diameter too small and chamber diameter too large?

[davepool]

I agree. The scorch marks on the sides of the casings show that clearly, but could gas blowback have caused the lips to curl inwards, too?

Barrel diameter too small and chamber diameter too large?

That's what i was thinking. What ever it is i would stop firing it until it was fixed.

[Schuetzenman]

I think it looks like a busted off piece of case neck is lodged in the chamber. Do you have a broken shell extractor tool? If so I'd say try putting it in the chamber and see if can pull out anything.

Those cases look more like what happens if when you're seating a bullet while reloading ammo and you don't get the bullet centered in the case and it gets rammed into the case mouth off center. Lastly, what is the make of the ammo?

[skorpion]

I had similar feeding issues with a Century FAL that had a cracked bolt, but the neck of the casings weren't curled in like what you've got as far as I can remember.

[Sidartha]

Could that be a secondary effect from the second shell trying to double feed and bending the throat of the first shell in on the chamber?
If that's the case then your problem could be solved with a repaired/replaced extractor.

Or like Schuetzenman said it could be a bit of shell stuck in there causing a bashed in throat and a slightly out of battery detonation would explain the excessive gas blowback.

[abpt1]

I would get a set of these and check the head space http://www.brownells.com/.aspx/pid=2...E_SETS#skugrid

also

Deth was telling me about something called bolt gap with the G3 rifle I wonder if this has the same style of bolt ?



http://www.youtube.com/watch?v=UoLrjpDB51s

[mriddick]

I'd check bolt gap but then again I do that on every roller lock rifle before I fire it I'm with the others, have you checked for something in the chamber neck. Since the barrel is a new USA made barrel I wonder if the neck could of been cut short?

[kimberkid]

If you pull the bullet and put the case in the chamber, then let the bolt carrier slam home does it curl the edges of the neck ... or does the neck get deformed by slamming into the trunnion because it doesn't eject? I ask because the necks aren't curled very uniformly as I would expect them to be if the chamber was cut short or if there were a piece of broken shell in the neck.

The "scorch" markes are normal, HK chambers are fluted to equlize the pressure and aid in extraction. You see the same thing on factory built HK 91's and 93's ...

The typical problem with the ejection is usually that the trigger pack doesn't fit snug up aginst the bottom of the receiver at the back of the mag well. When this is the case the ejector doesn't go in the slot on the bolt and catch the edge of the case, forcing it out of the bolt through the ejection port ... if there is "slop" it can be checked by making a small shim and placing it on the shelf before installing the trigger pack.

[BISHOP]

Great comments guys. Gives me things to look for and watch.

OK. here is some feed back from me.
The ammo was some surplus brassed cased tracers I bought many years ago (they never trace until it hits something, like the ground) and one steel cased Herter's brand ammo (russian stuff).
I did the steel cased amm just to make sure the problem was happening every time I shot.

I know that I should be using some kind of shim guages, but the very middle of the bolt to the carrier has no gap VISUALLY.

I dissassembled the gun today and checked the barrel/chamber and saw nothing in there.
I bought some JP Blaster and sprayed the hell out of the bolt and carrier to dislodge anything that may be in there.

I will do some checking with the ejector and trigger pack. I will be shooting it again tomorrow to check specific things.
I want to shoot single shots without a mag in place.


BISHOP

[Solidus-snake]

Sounds pretty rough man, id be extra cautious were I.you.

[BISHOP]

I checked the ejector and it moves right up into the bolt when and where it should.

Whay I am thining may be the problem is the buffer on the bolt.
I don't know what it should feel like but when the carrier gets to the end and the buffer hits it gets very hard to move the last inch +/-.
I can't find my bullet puller to check an empty shellin the chamber.

It is a Century with new American made barrel...Maybe it just needs some serious breaking-in.


BISHOP

[abpt1]

I highly doubt that... and strongly suggest you not fire that till you know for a fact its safe to shoot.

But if you do... make sure to have KK video tape it......... lol j/k...

[alismith]

I highly doubt that... and strongly suggest you not fire that till you know for a fact its safe to shoot.

I second this advice. With a gun, things go from "fine" to "fatal" real quick.

[BISHOP]

The empty shell is being jammed into the top of the trunnion when it fails to eject and then loads another rd.
You can see a nice clear brass circle mark where the shells are hitting.
Thats why I want to shoot individual shots (which I failed to do the first time shooting) to see if the shells come out looking all rolled again.

I think so far its a fail to eject problem.


BISHOP

[308]

I think it looks like a busted off piece of case neck is lodged in the chamber. Do you have a broken shell extractor tool? If so I'd say try putting it in the chamber and see if can pull out anything.

I had a CZ52 that did something similar. A broken shell was stuck in the neck of the chamber and I could not see it. It came that way from AIM...not their fault, probably was that way for a long time.

And to one of the comments above, those powder markings on the casing are indicative of a fluted chamber design...all CETME types do that to the brass.

[Schuetzenman]

I had a CZ52 that did something similar. A broken shell was stuck in the neck of the chamber and I could not see it. It came that way from AIM...not their fault, probably was that way for a long time.

And to one of the comments above, those powder markings on the casing are indicative of a fluted chamber design...all CETME types do that to the brass.

Dealyed roller lock up actions have to have those flutes. If they don't there's too much case in contact with the chamber and the action won't have enough energy to cycle. Tar based bullet sealants on surplus ammo are known to plug up the flutes and turn an HK type weapon into a single shot. In as much as this is a new US made barrel I wouldn't put the possibility of flutes cut too shallow out of the running as a contributing cause here if it is short stroking the recoil cycle and jamming the case into the trunion.