TM Hi-Capa 5.1 slide locking up

[Slapjack]

Hello all,

I have a TM Hi-Capa 5.1 that is a couple of years old. I've consulted a couple of players already on these issues, but nobody seems to be able to offer a solution that works, so I'm opening it up to the community. The gun is stock except for a metal, threaded outer barrel on this inside, and a Tanio-Koba grip (so that it can fit into a SERPA). Here are the specific issues I am having

• About 90% of the time the trigger is pulled, the gun will fire twice. This is not a double-feed, it actually FIRES twice, cycling fully on the first shot, and...
• 90% of single-fires and 100% of double-fires (mentioned above) result in the slide freezing about 3/4 of the way back. This is NOT the slide-lock function like when a magazine is empty. In order to continue normal operation, the slide must be tapped forward or pulled back slightly and then pushed forward. Every once in a while it appears to be stuck on the hammer, but most of the time this is NOT the issue.
• On occasion, the slide will COMPLETELY freeze in this position, and the only way to continue normal operation is to give the whole gun a hefty love-tap on the end of the barrel (force parallel to the barrel)

Fixes that I have tried

• Completely cleaning and lubricating every part of the gun, including disassembling everything I could find
• Increasing the tension of the recoil spring. This had no noticeable effect.

Other details: I've been using propane in the gun from the start, and adding lubricant at the recommended intervals. The problems were not immediate upon doing this, nor were they immediate upon installing any of the upgrades. I've had the gun since...probably 2009, and these things only started happening some time last summer.

[TheEnd]

I've never worked on a Hi-Capa, but two things stand out to me. You swapped grips which could be throwing off your mainspring, and the threaded barrel. I think you are having two separate problems. The double fire sounds like the disconnector isn't working and is letting the gun shoot full auto. The disconnector is the furthest prong on the right. Check that it is able to slide up and down freely and that the mainspring is pushing in the right spot. Also check the tip of it with the slide off and check the under side of the slide where it rides. If those areas are heavily worn you will need to reshape the ramps or replace the disconnector.

Your jamming problem sounds like the locking lugs on the barrel aren't working right. When the slide is pulled back the barrel should drop down vertically, then move slightly back. If you look under the slide you will see the two locking lugs which fit into the front of the chamber. Check for any heavy wear on the lugs, and check the ramps under the chamber. If those are out of spec they won't let the lugs drop enough to clear.

If possible switch back to stock parts and see if the problems go away.

[Slapjack]

Ok, so I looked at the spring in the grip and it seems you were mostly right. This is what I did: The middle tab on the spring was bent back a bit, and I noticed it wasn't quite pushing the reset lever back all the way. On a Hi-Capa, the disconnector tab is in the middle of the spring, it seems. So after stripping the gun down, taking the grip off, looking around, putting it back together, and bending THAT a bit, it seems to be fully operational. No jams, no slide locking, nothing. Just ran about 2 mags through it, absolutely NO problems at all. The slide still seems to be a bit tough when there is NOT gas running through the system, but otherwise it seems to be functioning well. Something in taking the gun apart must have re-seated the barrel correctly or something. Thank you for your advice, it directly and indirectly led to fixing the problem. Hopefully it will not persist, but for now this seems to be sufficient. Thanks!

[TheEnd]

The middle prong should be the trigger (it is in a 1911). I've never been in a Hi-Capa so I'll have to take your word on it. Anyway, glad I could help.