Air Gun Home :: View topic - Hiding a QB78 inside a British Army SA80 Bullpup FINISHED!

Alstone · Moderator & Site Supporter

Looking around for a project and having a few QB spare parts the problem was to find something suitable to make with what I had in the workshop, and a Bullpup layout seemed the ideal as most of my shooting is done in heavily wooded areas.

I have always liked the layout of the British army SA80 Carbine and I think it would be ideal to loose a QB inside the casing, so with the nice weather I decided to get the project started, it’s not possible to copy an SA80 exactly but as long as it can be recognised as one then I will be happy.

So this is as far as I have got in three days. The main casing is 16g steel and the channelling Magnesium to keep down on the weight, the grip fore stock and shoulder pad is part of a AGS stock from Ebay £4.99. Keeping with my idea of hiding the complete QB in side the SA80 body, the end cap on the Co2 tube will be hidden in side the fore stock, and a special removal tool use the unscrew the cap, the QB trigger unit will disappear in the Magazine port, to operate the trigger a brass tube goes from the front trigger to the rear and in this will be a control rod, hopefully it should work well.

One other thing is the bolt I am doing away with the standard QB bolt and using my design of a straight pull bolt, which I have used on other custom guns successfully, it will stay in keeping with the SA80.

Al

broommaster2000 · Moderator

This is going to be a good one. Wink

Stevesteve · New Member

Very interesting Al,

Any posts showing the details of the straight-pull bolt?

Cheers,
Steve

Alstone · Moderator & Site Supporter

Hi Steve
I will post pictures of the bolt system when I get it finalised, it is something like I fitted to my 2240.

The bolt knob it’s self slides in and out on a shaft fastened into the bolt, this is spring loaded so that when you push the bolt forward to close it drops into a recess which locks it in place, to cock you just pull the bolt knob out and back.

Al

Stevesteve · New Member

Ah thanks Al, that makes good sense!

Cheers,
Steve

paddyfritz · Member

Nice

broommaster2000 · Moderator

Is it also going to be magazine fed?

Alstone · Moderator & Site Supporter

ZipSnipe · Veteran Member

For the front trigger are you going with a sliding trigger or a pivot type trigger? Remember on my Bullpup once I switched to the delrin plastic slide, it gave it a nice trigger pull.

The key is to add the least amount of weight and drag on the trigger so that it can use the springs in the existing trigger(qb)

Looks great so far!!!!!

Alstone · Moderator & Site Supporter

Alstone · Moderator & Site Supporter

I finished the bolt system this weekend, as I said I intended to use a design of mine for a straight pull bolt system so it would be more in keeping with a full auto rifle.

The principle is simple the base of the bolt knob is smaller where it slides against the face plate, and when closed the knob drops into a recess in the faceplate and is locked, to cock it you just pull the knob out and back.

Al

broommaster2000 · Moderator

Big Ern · Veteran Member

Wow! This is just too cool Al!!

Alstone · Moderator & Site Supporter

Getting time to work on my custom QB as been difficult what with school holidays and a dose of flue, but were back in business now.

I have got most of the stock/frame finished apart from the magazine holder and sight support, the sight it’s self for now will be a Walther red dot which I may change for a SUSAT at a later date, plus a front sight support to clamp around the barrel.

I have gone for the Carbine model as I think it looks better than the standard, plus I can us a very short barrel and it will still look right.

This is basically what it will look like when finished

Al

Alstone · Moderator & Site Supporter

Another update.
This job is one of the biggest I have attempted so far, I was going to get hold of a broken Airsoft SA80 rip the innards out and replace them with a QB78, but the cost of a broken SA80 was more than a new QB, So I had to make everything myself which takes time plus getting it all working.

I am at the testing stage at the moment everything works ok and it shoots well, it’s all the little bit’s that require finishing off that take the time, but I’m getting there.

I still have to shorten the barrel, finish the front sight mount and make a silencer which will be a bit bigger than normal, with the barrel being shorter and putting the output up to around 10.5 fpe it will have a bit of a crack when fired.

Al