Cryonics

Sorry for not responding. Things have been pretty hectic with all the Covid stuff. Unfortunately I do not have any good news. Last time I tried it was in May and still same problem. Having spent so many hours trying to figure it out I decided to shelf her for a while. Will get back to trouble shooting once I have time to focus on her. My concern is that she will blow up in my face by virtue of the round getting jamed backwards, so am a little apprehensive shooting it. I am thinking of redisigning the triger guard to see if I can get the casings to bounce down rather than back in but I still need to engineer this idea.

I did try 3 different main springs but no difference. I did not try a different recuperator spring but I do have a spare so can try that. I was also wondering about making an even larger 11mm booster hole but did not know if that would be prudent or done before. The gun is quite drag free as I do use the recommended TW-25B grease that TWN recommends.

I am running 8mm mauser. The PPU ammo almost jams instantly on the first shot. I tried some russian ammo that jams probably every 3rd of 4th shot and some romanian ammo that jams every 7 or 8 shots. So ammo has made some difference but still makes it unusable with the casings stove piping. Another concern of mine is that I have the spent casing in the barrel upside down and then a bullet trying to enter the barrel and gets stuck half way in. In some cases that top part of the bolt got very close to the firing pin. Has anyone heard of people having this issue having a round actually go off while the other casing was in the barrel. I can see a huge catastrophe with that scenario.

I agree this whole thing is perplexing to me and even watching the video and seeing the case actually bounce back up and into the receiver makes no sense to me. Has anyone tried redesigning the triger guard so that when the casing hits it the casing bounces down rather than up? I know with the canvas brass catcher attached the shape on the rear side of the catcher is curved making the casing actually bounce up. If it were a triangle shape angled down maybe we could get the casing to bounce down?

I know it has been a while but life took over my time and only now that we are on lockdown that I was able to try some of the suggestions some of you suggested. I did get an 11mm booster cone, but unfortunately same problem. I did try adding the Yugo made brass canvas catchers and unfortunately same problem. I checked the ejector plate and she is very tight. I even tried different ejector pins but to no avail. The only thing I did not try was using larger ejector plate screws as I do not have any and was uncomfortable driling a larger hole into the gun. At this point I am at a loss of what else to try

So are you suggesting I purchase another booster cone? I thought the ones on the TWN where the same as the auto. I see two versions on the APEX site, one smaller and one larger opening. Which would you recommend?

I recently purchased a semi auto TWN MG34 and right from the start she would stove pipe the spent cartridges. I tried just about eveything to fix the issue but to no avail. So far I changed the recoil spring, barrel, bolt assembly, ejector pin and many other parts. I decided to take a high speed video of the problem and it seems to be something really silly and easy to fix. Basically the round is extracted, comes out, bounces off the trigger guard and goes back towards the front of the rifle into the ejection slot and then gets slamed back into the gun by the bolt assembly. It would seem that by adjusting the angle of the trigger guard so that the cartridge would bounce downwards instead of upwards would solve the problem. Unfortunately I tried attaching various things to the trigger guard to adjust the deflection but to no avail. You can see the high speed video at If anyone could look at the video and offer some kind of suggestion as to what might be happening or a possible fix, would be greatly appreciated.