QB78 bulk fill efficiency.. How do I improve it..??

[Ribbonstone]

Idaho....and co2 in the winter...not predicting a great outcome in freezing weather (OK...for today and tomorrow you might get into the 40's).

[Tgomez82]

Yup I hear ya there, that's why I'm thinking a hpa bottle regulated to 900psi output should be in the near future....

[Ribbonstone]

That can be done.  Simplest way is to tether an HPA bottle to the bulk fill nipple and just deal with a coiled hose between you and the bottle (which in winter, can just be stuck in a coat pocket).

But no one seems to care much for tethered bottles while wandering the woods; it's like a bungee cord running your quick shouldering and always seems to find a branch to hang up on. Worked fine when staying in one place.

Won't work with a co2 so well even if the co2 bottle is nice and warm inside your coat...the co2 gets cold sitting around inside the air tube of the rifle.

[Tgomez82]

I was thinking tether it when I'm on the bench and when I'm walking the woods or te desert I can put it in my pack and just bump the rifles as needed. A good carbon fiber 90/45 bottle should give me a few fills and won't way too much I think..

[Ribbonstone]

Given the standard QB tube's volume, using something like 850psi air (which is often the cheap-defalt setting on paintball tanks....be sure it is NOT one of the ones set for really low pressure (like 450psi) paintball applications) are likely to get 3-5 "good" shots per fill.

(And if your extension doubled the volume, then double the shots to 6-10.)

MAy as well keep it tethered as that's likely to be less of a PIA than hooking it up every 5th shot.

For the really inexpenvise end of things, the Al. 48ci 3K tanks are as cheap as HPA gets..can normally find them (new) on line for about $40-50.  Maybe another $25-30 for a coiled remote line.

Filling would be way of a paintball shop, so you'd be screwed out in the woods once you run out of air (but there's a gauge to warn you of that).

Power of the typical 800-850psi air is about the same than normal warm weather co2.

But (assuming no leaking) how many shots could you get from a 48ci tank?  Well, it should be proportional to a 3K 13ci tank at 800-850psi, which is depending on the way the rifle's tuned.  Worst case, somthing like 250 shots...best case, something like 500...then back to the paintball store.  Do have one QB79 13ci HPA (800-850psi) that manages 200 shots at 12 foot pounds, but I've worked the snot out of it to get there....so for that one, if it were a 48CI tank would be up to 800 shots per fill.

The four main down sides to this are:

1. Co2 tends to swell o-rings, which actaully slows any leaks to neary nothing.  Air won't do that and kind of looks for ways to leak that co2 won't.  Not always a problem, some co2 guns are actually sealed well enough for air...others just disguise their leaking (see bottom text).

2. You're hauling around a 3" wide/ 9" tall metal tank connected by a coiled line to the rifle.  Really doesn't bother me to be teathered with I'm bench shooting, or whan set up in one place rather than wandering around.

3. Are linked to the paintball shop for a fill...and they tend to not be open or far away when you need a fill NOW.

4. Best to turn the tank to "OFF" before you are finished for the day.  Then shoot the pressure down (good shots at first, just burps as you go along) until you can easily detach the fill line.


Disguised co2 leaking.

Fill it today, and it still shoots next week, so it didn't leak...right?

Well...maybe.

But with co2's self-regulating nature, you could have put 2oz. into on day 1, and 7 days later it has 1/2oz in it...but it will shoot just as fast as it did on day one.

[Tgomez82]

Wow lots of info to process. I have a remote line and 2 20oz co2 tanks, I will look for a couple of hpa tanksto purchase in the near future. I think for long grounds squirrel shoots from the table being the there's won't b a problem for me but I will probably stick toto point off the air tube when out stalking rabbits and squirrels I want to do some more mods to get more velocity and in turn a higher fpe but that will be a later post thanks again I really do appreciate all your info and you sharing your knowledge with me as I am just getting into co2 and pcp's

[skorec]

2) The barrel doesn't NEED to be recrowned if you already have a tack driver.

Can you axplain mee please what is it ?

[Tgomez82]

2) The barrel doesn't NEED to be recrowned if you already have a tack driver.

Can you axplain mee please what is it ?

What he means is if the rifle is already shooting accurately there is no need to modify the barrel. A "tack driver" is a rifle that shoots pellet on top of pellet over and over again.

[larspawn]

Good stuff here except I don't know about cleaning every 30 shots. I just go by rule of thumb it's good until known accuracy starts falling off. Then I clean. But honestly that's like never for me outside initial cleaning.

I didn't see discussion on exactly how you are bulk filling. one thing I'd correct from some of the other posts is you aren't trying to move "gas" from your supply to the rifle. What you are trying to do is move liquid CO2. This may be why you aren't getting many shots per fill. You want less gass and more liquid. The liquid then turns to gas in the rifle to propel your pellet.  This is actually what makes CO2 "self regulating" as I believe CO2 vaporizes at 850-900 psi. So as long as you have liquid you have self regulation. Velocity will quickly fall off as soon as you have no liquid.

Anyway, to accomplish this you want supply to be above the rifle so liquid can flow. You also want the rifle to be cooler than the supply. I've gone so far as putting my avanti 888 tubes in the freezer.  Since a rifle won't fit in the fridge don't shoot until you are empty. Save some gas and just before filling rapid fire as many shots as you can. This will cool the rifle tube and help in max transfer.

I have a HUGE tank I bulk fill from. I just picked it up and I know that's more than a lifetime supply for me. I swiped it from the bar I used to own. Then took it to the gas supply house and traded for a tank with a siphon tube. This pulls liquid from the bottom of the tank so I don't need to invert tank.  If I didn't have siphon tube or invert you can figure out I'd be pushing only gas from the tank to rifle.  That sucker is like 30+#s and I didn't want to build a wall mount to hold it upside down.

Hope this helps.

Here's my lifetime supply of CO2 with a glam shot of my Mike Melick hotroded QB deluxe in .22. As I believe Ribbonstone said hot rodded CO2 is a gas hog because your dumping so much volume the liquid doesn't completely turn to gas. Hence each shot you are really inefficient and pushing liquid and gas. As with all CO2 guns giving 10-15 seconds between shots is always the protocol.

[vigilandy]

That's a nice looking QB!  I got a similar CO2 setup misus the siphon.  And yes,  it's a pain to invert the tank.  In about 20 years  when this one is empty I'll exchange it for a siphon tank.

[larspawn]

That's a nice looking QB!  I got a similar CO2 setup misus the siphon.  And yes,  it's a pain to invert the tank.  In about 20 years  when this one is empty I'll exchange it for a siphon tank.

Yeah Andy, I love having that tank. Although I should shoot more CO2. I really only have a few bulk fill guns so this is actually several lifetimes worth.

That shroud is a coveted Rich In Mi "Q". Never see a RIM Q ever come up for sale. Even with it and the weight this beast has significant muzzle flip. It makes a really cool sound too. It's like a deep thwuuump. Unlike the sound sig of any of my other moderated guns. It's developed a leak so I'll need to rebuild it. Geez it's been like 8 years since I've rebuilt a QB. Used to be like field stripping a 1911, I could do it blindfolded. Now I'd be fumbling through it. Lol. I did break out the QB rebuild kit. Got literally 100's or each oring. Hahah. Ok maybe I'm inspired now to crack this open. Iirc it was shooting 14.6gr at 820 fps?  I remember first getting it and shooting my Beeman spinner trap. I was saying to my son that the animals seem smaller than I remember. Then we walked up and saw the QB was blowing the feet off all the animals!  Cheap steel! 

[skorec]

If I clean end off barrel ( approximately   2cm )  by cotton buds after every 30 shoots the accuracy normally never fail .  Boresnake and Ballistol  I use after 100 - 300 shoots only .  But  it can depend  also of CO2  purity ?  After I have made universal reservoir cap I  use  very cheap UMAREX CO2  ( 12g  capsules )  only for paper breaking  at  summer.  After each CO2 shooting I clean barrel whit Ballistol before I put QB78  into the box for longer  time.   
For  year-around   little  range  scare starling  cases I a have filled my  QB78 reservoir  whit high pressure  air. 
8  shoots  magazine is  enough for approximately  4 days.
SfmBE 

[SpiralGroove]

Hey Andrew,
That's the Coolest QB I've ever seen .
Kirk

[Bentong]

Hey Andy, is that a RichnMich set up?

[Tgomez82]

Andrew the stock in your QB 78 is something to be envious about my friend good looking rifle!! Is that something anyone can buy or is it custom?