tanaka m700 problem

[sharpy]

just wondering if any one has had the same problem?
I have a realy great tanaka rifle which I would love to use in a game, but the problem is that the first 3-5 shot that I fire come out a realy low fps which drops the bb out of the barrel about 30 feet before hitting the deck .
after the first 5 shots it goes back to normal and can hit out to 70 odd meters.
then if I leave it for another 5 mins, the problem starts all over again.
I was just wondering why it might do this.
I am running it on propaine at 480 fps, the gas is not cold, the hop is set nicely and the bbs I use are good quallety.
any help would be great

cheers

sharpy

[flatrajectory]

Re: tanaka m700 problem

HI,
Sounds to me like the striker/internal hammer is hitting the gas valve too light a strike ( i.e a week striker spring).
After you gas up the mags the gas pressure is high initially, if the strike is too light it cannot overcome the gas pressure. After a few shots the gas pressure drops so the gun shoots ok, then if you leave it to warm up again the gas pressure increases again etc etc.
Try using 134a gas ( which has a lower pressure) and which the rifle was designed for, if it then shoots ok then I was right. If you intend using green or propane then you may need a stronger striker spring.
ttfn

[dope_on_a_rope]

Re: tanaka m700 problem

Or rather than replacing the spring, just take the bolt apart, and tighten the screw that holds the spring in place right up. If it is already fully tightened, you might want to replace something. Although it's most likely a spring issue, it could equally be down to a stumpy valve knocker, or mag striking plates that are worn right down.

[sharpy]

Re: tanaka m700 problem

cheers guys, will try with different gas and let you know

[sharpy]

Re: tanaka m700 problem

ok so problem does seem to be with the striker spring after all, thanks for the great advice on that only other thing is does any one know where I can get a stronger spring as all my usual places dont seem to stock them

cheers

sharpy

[dope_on_a_rope]

Re: tanaka m700 problem

Can't mention that mate. I suggest you read the forum rules.