Cetme Extraction/Ejection Problem

[Drakejake]

I took my new Cetme with stainless receiver to the range today and had puzzling results. I first fired a mag from the hip, to make sure the rifle was safe. Brass looked fine. But when I began firing from the shoulder, there were repeated jams caused by the spent case not getting out of the way of the new round being loaded. This is the opposite of limp-wristing, which can cause jams by having the arms absorb energy needed for extraction and feeding. Here the resistance caused the jams. This happened with all three mags I had with me, so I do not think this is a mag problem. Would you say this is a timing problem? What is the solution? (I am familiar with the Cetme discussion groups but wanted to address this question to a wider audience.)

Thanks,

Drakejake

 

[RecoilRob]

Interesting problem!

After pondering it a bit, a couple of things come to mind. It has been a while since I had the 91 & 93 H&K's but don't they use the hammer to not only fire the cartridge, but to hold the wedge (cam?) forward which holds the rollers out into the receiver?

Assuming that everything is machined properly, a very weak hammer spring might allow the bolt to retract a bit early. This would also fit in with your shooting from the hip working OK.

The rifle recoils, which makes it harder for the bolt to move rearward. Just as the Benelli M-1 compresses the action spring as the shotgun recoils, your movement would retard the opening a bit.

I don't remember just now what the ejector looks like on one of those but it might be sticking and not as strong as it should be. If the bolt is making it all the way to the rear, the empty should be out of the rifle and flying far, far away before the bolt comes forward.

Thinking as I type, I'd go for the ejector stuck/weak first and look at the hammer and mainspring next. When you smartly eject a loaded round, does it throw it into the next county? IIRC, mine would really flip the rounds out when clearing it.

The mainspring being weak or shortened could allow the bolt to smack the back of the receiver and go forward quicker than if it was retarded properly on the way back. Or maybe not.

Ok, enough uneducated musing. Perhaps some of the CETME experts will chime in and solve your problems. Good luck!

 

[Drakejake]

Ejector may be sitting too low in the bolt head. Perhaps something about shooting from the shoulder reduces the ability of ejector to engage the spent shell. A common fix for Cetmes is shimming the trigger pack so that ejector rides higher and engages more of the case bottom. Since new round is being pushed from the mag, one would think that the bolt assembly IS going far enough back.

Drakejake

 

[s&w 24]

what kind of ammo were you using?

 

[Drakejake]

South African milsurp.

Drakejake

 

[s&w 24]

how does your recoil spring and guide look?

 

[Drakejake]

Recoil spring and guide look fine. I have put some auto body compound on the trigger pack shelf to raise the front of the trigger assembly and lift the extractor higher into the groove on the bottom of the bolt head. This should make sure that the extractor has good contact with the bottom of the case. This problem and this solution are common with the Cetme, according to what I have read. I will check the results out in the woods today. In my other Cetme, which has worked perfectly, the ejector rides higher against the bolt.

I speculate that the ejector was just high enough to function when shooting from the waist, but that flexing of the firearm or movement of the ejector when shooting from the shoulder caused the ejector to be too low to operate.

Thanks,

Drakejake

 

[s&w 24]

good thing you figured it out cause I'm out of Ideas!