QB78 IN JACKAL STOCK

I wanted to build a tactical looking QB78 and had seen some versions using Jackal stocks. I had the idea to mount weaver rails on the stock for a Bi-pod/handle , torch and laser, a long cranked bolt and either an air stripper or silencer. The Jackal stocks are robust and look good. I have a couple of the Air Arms High Powers and really like the look and feel of them and the shoot well.

I was able to purchase a Jackal stock from http://www.relics.org.uk/productinfo.php?product=584

It takes a reasonable amount of modification to make the QB action fit , the main work is around the trigger area but if you work slowly and carefully it is fairly easy, you need ideally a sharp chisel , a Dremel type tool and some sanding cutting bits and a hacksaw.
 I bolted the action to the bottom of the magazine area with a longer bolt and hid this with the magazine, this needs to be a good fix as you don't want the action to have any movement .
the stock has to be shortened so you can get to the end of the gas tube to put the CO2 bulbs in, you can purchase long tubes that take 4 capsules and there for the stock could stay longer but I prefer it at this size with the 2 capsule tube. The weaver rails screw in to the stock quite well as the plastic is thick and strong, the bi-pod is a dual purpose one , bi-pod or handle. Below are some photos taken whilst fitting the action.

Below are pictures of the finished article , I am waiting for a laser to arrive and it will be fitted on the opposite side to the torch.

 

 

  

 

 

 

 

 

 

XS78 CO2 Rifle .22 (QB 78)

The XS78 .22 CO2 rifle is probably one of the most mod-able rifles around, the standard format out of the box takes 2 x standard 12g powerlets and power will be any thing from 6lb to 9lb , they usually shoot accurately out of the box. The modifications you can do to these rifles are almost limitless and every one ends up with a  unique rifle. Below are the mods  I did to 2 such rifles my own and my sons.

Strip down - https://docs.google.com/open?id=0B4hV3nw-qXdnUU1zaXh0emsxM00  this link takes you to a full strip down guide.

Tune up - First job is to get the power up and smooth everything out to get consistency. In the UK  we are limited to 12lbs , for a .22 gun  you only need to change the transfer port, remove the filter in the valve, polish the internals and bolt, open up the bolt probe using a dremel and change all the seals. You will need to purchase a chronograph or get access to one (£60.00) so you can check you are not over power, it is very easy to go over power !  . CO2 is effected by temperature, the warmer the day the more powerful the discharge and on a cold day the power will be down, you need to make sure your gun will not go over 12lb on a hot day - usually it is advisable to tune up to about 11lb at room temp and check on a hot day with the chrono. Seals and transfer ports  can be purchased from https://www.youtube.com/watch?v=uY1WjhJPFRk  these are the best quality and a good price.

the above shows you the parts to polish and de-bur , this will make the gun smooth, you need to lube properly with moly grease on metal parts and silicon grease on the rubber seals , this protects the seals from the CO2.

New stocks - The most dramatic change you can make visually is to change the stock, the Webley AGS stocks are readily available, cheap and do not take much work to fit the 78 action. Below are the 2 styles of stock fitted to our guns.

With these stocks you get a gap left at the back of the action , this can be filled with wood or metal to finish it off , I decided to put something useful in the gap --- a shot counter. the .22 guns  will fire approx 50 shots on 2 capsules, it is best to store these guns charged with CO2 so I click each time I fire and when I get to 50 its time to change the capsules, also means when I put the gun away i know how many shots i have had when I use it again.

Rowan Mag - http://www.rowanengineering.com/products3.htm

This modification makes the gun multi-shot , they work well, all you need to do is put high mounts on your scope . .22 gives you 6 shots.

I highly recomend these guns they are good value recoiless guns that are easy to work on and make your own. The only word of caution is that the .22 can easily go over power so make sure you have access to a chronograph. The .177 is harder to get up to 12lb but can be done.

manual link - https://docs.google.com/open?id=0B4hV3nw-qXdnRVRBeExUQkhzZVk