Ak12 Low Joules

[Rogerborg]

1.03J and 338FPS with 0.25BB

Er, 338fps with 0.25g would be 1.32J, technically a Section 5 firearm.

 

[george1976]

Er, 338fps with 0.25g would be 1.32J, technically a Section 5 firearm.

1.33 Joules I believe it was, got it mixed up.  I don't get the part with the section 5 sorry.

 

[Guest]

1.33 Joules I believe it was, got it mixed up.  I don't get the part with the section 5 sorry.

you will,  @Rogerborg will explain I’m sure ?

 

[EDcase]

...I don't get the part with the section 5 sorry.

Basically at that power it becomes an illegal firearm.

Certainly won't be able to use in a game.

 

[george1976]

Ahh, then I need to try the stock softer spring, good thing it has quick change.

?

 

[Rogerborg]

Yup, if it can shoot full auto, and can shoot "any missile" at over 1.3J (the State could drop in anything from 0.12g to steel BBs in there if they fancy) then it's not an airsoft gun by the definition in the Policing and Crime Act .2017

So by default that makes it an airgun, which is a "lethal barrelled" firearm, and the full auto makes it an offence to possess, purchase or require under Firearms Act 1968 Section 5.

It's a largely theoretical issue, it's not like even HPA monsters get tugged by the fuzz on a regular basis, just something to be aware of.  One local site has banned DMRs completely, in part so as not to encourage anyone to turn up with a >1.3J gun that can be readily convertible to full auto (i.e. by removing an external stop-screw or similar).

But, again, HPA...

 

[george1976]

What is the best way to go about this guys?

Change the spring to some M90 or change the cylinder ?

Are there really any pro's and cons to anything or I can do whatever I want?

Thanks

 

[EDcase]

What is the best way to go about this guys?

Change the spring to some M90 or change the cylinder ?

Are there really any pro's and cons to anything or I can do whatever I want?

Thanks

Changing the spring would be easiest.

 

[Rogerborg]

Changing the spring would be easiest.

And kindest to the gun.  I'm down to an M90 in my M4 now after also getting a winning ticket in the air-seal lottery.

 

[EDcase]

And kindest to the gun.  I'm down to an M90 in my M4 now after also getting a winning ticket in the air-seal lottery.

Oh yes, I was going to say that too.  Less strain on motor and gears.  Win win

(Cutting down the spring would be the next option. Cheaper but not as easy)

 

[Rogerborg]

(Cutting down the spring would be the next option. Cheaper but not as easy)

I'd go that way with a quick change gearbox, then nip off one coil, heat and flatten, and repeat as necessary. With a prehistoric gearbox, I'd buy a couple of springs (M90, M95) and aim for "eh, close enough".

 

[george1976]

I'd go that way with a quick change gearbox, then nip off one coil, heat and flatten, and repeat as necessary. With a prehistoric gearbox, I'd buy a couple of springs (M90, M95) and aim for "eh, close enough".

Nice gearbox inside this Arcturus, radiused, reinforced and QD spring. I had to cut more than a coil from my M100 spring, heat up the end, straighten them smooth it out.

Cycling between 1.14-15-16J now.

RPS sucks though, 12, thinking maybe change the motor or put in some 16:1 gears, apparently it comes with 18:1 inside. Stock motor couldn't pull back and M130 spring I tried in it, just choked. 

 

[Rogerborg]

Nice gearbox inside this Arcturus, radiused, reinforced and QD spring. I had to cut more than a coil from my M100 spring, heat up the end, straighten them smooth it out.

Cycling between 1.14-15-16J now.

RPS sucks though, 12, thinking maybe change the motor or put in some 16:1 gears, apparently it comes with 18:1 inside. Stock motor couldn't pull back and M130 spring I tried in it, just choked. 

Stock motors are sad motors.  I've had three Big Dragon motors (or rather "mortors") from Ali Express now, two M140s and an M160 for a DMR, and they've decently strong-fast for the money.

 

[Speedbird_666]

Stock motors are sad motors.  I've had three Big Dragon motors (or rather "mortors") from Ali Express now, two M140s and an M160 for a DMR, and they've decently strong-fast for the money.

How do they compare to the likes of SHS/Rocket etc Mr Borg? I see they work out about £5-7 cheaper than UK prices with 10 day shipping. I might take a punt on one.

 

[Rogerborg]

How do they compare to the likes of SHS/Rocket etc Mr Borg? I see they work out about £5-7 cheaper than UK prices with 10 day shipping. I might take a punt on one.

Beats me, I don't do Fortnum and Mason brands, but certainly better than a Tornado F1 aftermarket motor.  @Sitting Duck rated the M140 and M160s.

I've had three so far (2 x M140, 1 x M160), all with strong magnets. One of the M140s had enough inny-outy play in the shaft that I felt compelled to pop another 0.1mm shim under the end, but other than that, all good.

 

[george1976]

Just in case someone stumbles upon this thread looking for answers:

I had replaced the crap stock motor with a SHS high torque one bought from ak2m4 and the difference is clear.

Trigger is more responsive, and my rps increased to 15.4 (from 12) with the 7.4V battery.

The stock gears are supposed to be 18:1 on this AK.

Because of space constraints I think I will stay with the 7.4V battery and maybe change the gears to some 16:1 to add that couple more rps laterz.

I was thinking about a mosfet but not that worried about that now, I can replace that miscroswitch anyway if I burn it down.