problems whit walther p99 umarex-maruzen
 

hi, I´m from venezuela, and I have problem whit the blow back of me walther p99, its don´t make full the movement, and I have to pull too or tree times the triger to chamber the next bb... please if you have any solution please let me know because I love that gun... thanks

any upgrades on it (ie: recoil spring tension, metal slide), what type of gas are you using?

Is this an airsoft gun you're talking about, or the 4.5mm BB gun?

these dont have any upgrade, it´s standard and its for airsoft 6mm bb

and I´m using propane gas whit the silicon oil from AI adapter

pleaseeeeee
 

please I love my gun, but it dont work, please I need the solution for these problem...

your problem is the hammer spring, on most GBB's there is 2 springs (one on each side of the plunger,to pull it back) on this model , there is only one,,and its very small. This spring is not very strong, and it gets weak very easy.
You will have to find one for this gun .it is not easy all parts for this gun are very hard to find

It is horrible to find that part.

When you take the slide out, then remove the barrel/chamber.

Then remove the two screws at the rear, inside the slide.
Then remove the blowback unit, it's the little spring, about 2mmx30mm.

That spring gets weak after some time.

I replaced mine with a solid rod. This disable the blowback, making it some kind of "springer NBB" You would have to rack it to chamber a new round, but the FPS and precision go up incredibly.

is that the right measurement for the spring?, I was looking at my WE1911, it has a similar set up , and the spring is close but wider,I could try to find a similar spring ,and maybe modify the blow back unit,to accommodate the wider spring.I dont know i guess I'll think about that.

Nope, you CAN't modify the slide/blowback to fit something bigger.

Dia. is exact. I used a 2mm allen key to make the pin.

And I tried to fit lighter springs, TM P226, TM Hicapa, KJW P14 and some random springs I found.

Nothing is the right size AND hard enought.

No huh?,, well i guess i'll keep looking, that or maybe sell as parts ,metal slide , and barrel, right know i just shelved it .