Canadian Airgun Forum

QB78 out of the box gets good 40 shots above 420fps.
using bulk adaptor - gets 32 shots.
using Mac1 ext. tube + bulk adaptor = 80 shots.
The above # of shots also good if you only mod the ports
but would gives vel. in the high end of six hundreds.
If the valve is modded as well, 2 powerlets would give 25 shots
and bulk adapt. 15. and with the ext. tube about 50.
This is the best part of 9oz, stock QB or mod ports only
would give 420+ shots and mods all the way = 320+ shots.

Great stuff Sniper! A tanker version of the QB.
I can see your next mod is going to be shorten the main tube back close to the mounting stud to improve the balance. Maybe rework the stock, similar to a Rapid.

Yes, actually I would like to get the QB78T/QB79, out of the box comes with the bulk adaptor for paintball bottle but I can't even get the adaptor for now, so I created next to the best thing. I was surprised the QB is still quite light in weight, out of the box was 5.75 lbs, with the 9oz bottle is about less than 7 lbs. before the scope and now the centre balance point is right underneath the rear sight.
I was thinking about cutting the tube back but I got to find a good re-threading tool first. You're right perhaps that's the next project.

Hello Sniper

I sure if look long enough I will find it but do you have any pictures of the mod that you dig to the qb78, like what did you change and how much.

Avanar

Hi Frank & Avanar,

I gather all the shots, all what I can find:

Here it is:

I did an efficiency tune aiming for shot to shot consistancy and maintaining shot count ( I have no intention to bulk it at this time ) and increasing performance .The results were amazing ..consistancy is unreal ..power is up ..and get this so is shot count !!! Like you mentioned Sniper it comes shooting slow and gives 46-48 shots ..it is hot and gets 52 good shots ..very pleased with the results .

Frank

Yes, sounds excellent.
I was pleased with the result too as the way it was stock, new, but I was using 3 of them with 5 guys shooting, then it was costing so much on powerlets, not to mention the pellets constant shooting for 2 hours.

Help Sniper or anyother of you knowledgeable people out there. I started to take apart my qb78 but am unsure how to remove the valve body(the gold one). It does not seem to slide out and I don't want ot hit it too hard if that is not the way to remove it. Ideas?


avanar

Once again I post before I am finished asking questions. Sniper why the 2 holes in the valve body and how deep? Iam sure I will have other questions but for now that is it.

Avanar

There are some articles over at Charlie da Tuna's website on how to disassemble and tune the QB-78. You need a very wide screwdriver or a spanner to remove the valve assembly safely.

http://charliedatuna.com/co2.htm

http://charliedatuna.com/charlie_QB78_tune.htm

http://charliedatuna.com/co2_tune.htm

Happy reading......

I made a tool like this to remove the valve.

After completely taking all the pieces apart, you left with the tube and the valve inside, don't forget to take the screw that hold the valve at the bottom of it. Now from the front spray or drop alot of oil so it cover the internal wall of the tube for the valve body to slide out and then what I use is a deep socket wrench as big as possible to go inside the tube with along extension and hammer it from behind start by tapping it and get harder as much force as need it from behind toward to the front of the tube. The oil in the tube wall should protect from o-ring getting damage.


The two holes in the valve body drill them right thru untill the bit goes right inside the valve body, the two holes will provide much more co2 into valve body.

No, no, no, do it the right way......don't beat the valve out!!!!

.....lol..... don't beat it ... smack it .....
this intruction is from Co2UNE, I've done 5 so far and great success.

I guess, your way is ok too but I was thinking it would take so much time
to align all the valve parts back, unless you get lucky and get them all fit right in.
another problem how do you mod the valve head (the brass part)?.
There are 3 parts got to be done on the valve heads, exhaust port, angle port, enlarge the tubing port.