Gas Blow Back Pistol Building Thread

[docas101]

Mga bro!

Does anyone here interested in building or modifying a TM Hi-Capa?

If so, Please post in this thread.
you can ask questions or share your ideas if you have already done this. I understand that Life26 is a pistol lover and builder ;D .

Nowadays, there are lots of tutorials that can be found in the internet so building and modifying your TM Hi Capa wouldn't be a problem. It is dead easy and fun. ;D

We are going to learn while working on our pistols.


Here is my entry

My base gun is a 2 year old junk TM Hi-Capa 5.1


This gun is old and never been used for a couple of years. All the internal parts have been dormant for a long period of time. It has some issue like gas leak , very weak blow back and recoil and very low FPS. Therefore, this gun does not work well any more.

Objectives of this project:

- Rebuild and make it a high response secondary weapon.
- It can be used in all season.
- Highest velocity .98 Joule using a green gas.

WARNING!!!! GBB upgrade parts are expensive..

first step- change the stock plastic slide to metal slide



Video of TM Hi- Capa Slide Take Down.
www.youtube.com/watch?v=2G4fVhGqw5U&feature=channel_page
credit to : realbriguy

Steps on how to remove the piston from the slide
see image to follow.

1. unscrew and remove the rear sight.



2. remove the allen screw


3. and gently push the piston out from the slide.




Take note:
After installing the parts (inner barrel, outer barrel, hopup unit ,recoil spring guide,recoil spring, piston etc. ) in the new metal slide you might encounter some tolerance issue in the frame's rails.

I found out that the Shooter's Design (made in HK) metal slide is not a 100% drop in kit to the TM Hi-capa frame. there are some spots that require some sanding in order to run smoothly in the rails.

here are some of the pictures of a sanded rails.
warning - do not over sand the rails, it will lead to dis-alignment.



I machined 0.4 mm in the inner parts of the rail using a precision machine.
not recommended for those who do not have a lathe machine. Do not follow this modification




Here is the picture of the completed brand new metal slide
with DIY NBR rubber dumper, laylax 6.03 inner barrel, nineball recoil spring guide, PDI recoil spring, stock TM hopup rubber, nineball piston head and RCC rocket valve.


I was not able to take a step by step pictures on this.
I changed the stock piston head to a brand new nineball dyna piston head (Red) and
the stock loading nozzle valve I changed it to RCC rocket valve (Brass)

It looks like this inside the loading nozzle



Video of TM Hi- Capa Disassembly Guide
www.youtube.com/watch?v=kd4Q8a3sQAc
www.youtube.com/watch?v=Y7uEPV95jq0&feature=related
credit to: TheEarthwalker


I set aside my stock TM Hi-Capa hand grip and replaced it with Tanio Koba OD grip with 3 holes nineball trigger.






My TM Hi-Capa 5.1 looks like this now ;D

additional upgrade parts installed
CP hard steel hammer
CP hard steel hammer pin
CP hard steel hammer spring spur rod
RCC 130% hammer spring
KM gega magazine gas flow valve





more photos






My impressions after building.
I've got the smoothest slide that runs in the frame.
The extra weight makes feel good in the hands ;D

After relubing the gun and tested using a HF134a Gas.

from 190 fps it shoot now in average of 243 fps in HF134a Gas.
I can feel the hard kick and blow black produced by the metal slide and upgrade parts. ;D
I love how it sound, very crisp in every shot no twack, no pop, nothing.


I'm expecting to hit 310 fps + in green gas.
I will post update and video soon once my green gas canister arrive.


It cost me a lot, but I enjoy it, and that's what really matters in the end, ;D

Cheers,

;D





PS.
For non pinoys, please excuse me, my English is not my best. ;D

[toti]

Its great that youve brought up this topic! During winter we were a bit depressed out here in hamamatsu due to the cold and the wind. as what they call baka kaze.
and nobody felt like playing that much.
i got bored and didnt know how i could enjoy airsoft at home.
so i experemented on my Hi Capa.
I placed my Hi Capa magazine fully loaded with bb and gas in front of the heater for about a good minute. the magazines temperature was about 35 degrees. and sometimes it was too hot to hold.
but to my surprize without any modification what so ever it shoot an amazing 290 fps. for real!
try it!
weve been doing indoor speed shooting during winter it was fantastic.

[docas101]

Hi bro!

I have 1 stock ksc glock 23F that shoot 270-280 fps when the magazine is heated. ;D
This was a junk hi capa and the loading nozzle has a hair crack somewhere in the gas exit port. I order a new loading nozzle from Marui.ill give update when it is arrive.

I build this gun to work in the outdoor during winter season without bringing a heater or hair dryer in the game field. hehe

by thw way, I edited the title of this thread. This thread is for all kind of GBB pistol. ;D

[Hazard]

Although I already have a dependable Hi-Capa 5.1, I am thinking of building another dedicated gun for indoor games. Picking up some tips from this thread, my planned parts are:
* PDI 01 inner barrel
* Nineball hop-up rubber
* Davidson Custom slide
* Tanio Koba/Guarder Tactical Grip
* Freedom Art Long Railed Frame
* Firefly Rocket Valve
* Nineball blowback piston

[docas101]

ok ang mga upgrade parts mo bro except sa metal slide.
na try mo na ba i fit ang Davidson Metal slide mo sa TM hi capa middle frame? wala akung makita na review sa Davidson custom slide.

ito yung bagong update sa TM hi capa ko,
magazine, magazine catch, hop-up chamber at loading nozzle nalang ang natira na made by Tokyo Marui sa TM 5.1 hi capa the rest of the parts are 3rd party na

new parts installed : Freedom art railed OD green Hi capa 5.1 middle frame and my own design custom made A5052 CNC machined high performance air seal piston head for TM hicapa, TM colt1911 and TM P226




here is the picture of my custom built 5.1 Hi capa now



100% ready to fire ;D

[Hazard]

Recommended kasi ni James 'yung Davidson Custom. Meron na ako actually. Very light, kailangan lang ng konting sanding sa frame.