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Tanaka M40 stock hop up questions, fps and target

2193 Views 2 Replies 2 Participants Last post by  reezo
Hello everyone,
after reading as much as I could on the forums, I thought about opening this specific thread:

my Tanaka M40 PCS has the stock hop up unit and stock inner barrel. I am using the Tanaka for target practice..since I do not have fps restrictions I took care of extending the preban valve to allow as much power as I could. I've installed the King Arms reinforced striker spring in the bolt and steel impact plate on the magazine. So far, apart from using teflon tape to remove barrel wobble etc. these are the only upgrades I have on the gun.

I am taking some relaxing time to get a feel of the gun and do some practice shooting to get acquainted..but I am having some issues with the hop up unit (stock).

I should say I am firing Madbull 0.40g BBs, first.

My question is: with the gun set to the highest FPS achievable for the moment, some people recommend NOT using the hop up at all..this means rotating the hop up wheel counter-clockwise until it pretty much stops its friction with the small plastic pin it rotates on (correct me if I am wrong).

I noticed some pretty weird behaviour with different hop up settings, and I could not find one setting that worked best..I must say target practice for now is happening at around 10-12 meters (around 40 feet).

When the hop up was working, I had to aim much lower than my zero because the BBs were arching up quite a lot..actually they pretty much begint to arch at 9-10 meters (30 feet roughly) so, when aiming dead center in my sights, the BB would fly JUST over the target itself right before hitting hit (and therefore missing it :)).

My questions are:
1) Is it generally better to use NO hop up with high FPS for target practice? This means I will have to zero the sights again, of course.
2) No hop up equals normal projectile trajectory (=arch?) as to where hop up makes the BB "surf" the air in front of you (a little weird)
3) The stock Tanaka Hop up seems quite is a squared plastic patch with a circle-shaped 2mm shim that goes into the inner barrel hop up hole (most of you know this already, I know). It looks like mine is showing signs of tearing my question is: I thought about applying a square patch of adhesive aluminum paper on the hop up rubber, directly on the square rubber that gets pushed by the hop up pin. Would this reinforcement work, in theory? I would make it exactly as large as the hop up square rubber in size and the aluminum foil width is almost negligible..
4) not hop up related: would you recommend me to drill the stock nozzle to get an increase in FPS..after all I might just wait for the King Arms nozzle upgrade (which comes from the chamber conversion, allowing me to put a 6.01 tightbore barrel) but I was curious :)
5) do you PCS owners keep the PCS screw to where it's rear end just lines up with the bolt "PCS opening"? Or do you keep it slightly more screwed towards the nozzle, so that you can see the PCS pin near the nozzle but still very far from it?
6) How long do you keep the gas flowing into the magazine? I've read 4-5 seconds but the valve on my mag starts spilling gas out of it so I was just wondering how long you guys keep it "down" on the mag eheh and how many shots you usually get, considering I shoot at the highest power.

I know FPS is not all is needed, I am trying to set a baseline I can get to know my gun with and then work my way around it.

Thanks for the help,
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I was target shooting with my Tanaka, before I brought it to its first game, at aprox. 55 feet. I had the hop-up barely on and it was shooting great. However, when I did go to my first game the bbs would dive at 70 feet because there wasn't enough hop-up. So when you actually do field it you will have to vastly tighten the screw to get the bb to go 200ft or more. This is normal though because the hop-up is set for your back yard, which is small.

There is a rubber hop-up upgrade set from G&G which includes the 2 hop-up rubbers and the 1 magazine fill valve rubber(goes on the bolt).

I would just buy the conversion kit from King Arms and also buy a Nine Ball Purple VSR-10 bucking along with your choice of high performance TBB. Unless you can find a Best Gun hop-up set(cheaper aprox $65) for the tanaka, although the King Arms kit gives you more variety of parts.

I've been told that 85% open on the PCS bolt is optimal, however mine is more like 75%. may vary from rifle to rifle.

Stop filling the mag when the gas starts "spilling out"

On a second note, you may want to invest in a pre-built or make your own co2/hpa rig. Should give you amazing results because of improved consistency with co2/hpa over Propane or Greengas. Im currently making a co2 rig, when im done(1-2 months) I will post a guide here of how I did it, but an excelent guide can be found here:

I get about 50 shots on a full gas fill. If you switch to co2, depending on your fps, you can get 50-70 shots per c02 cartridge and they are much easier to change out then carrying around a Propane tank.

Also, the G&G rubber might give you more Fps because it creates a better seal with the mag.

I invested in the G&G gas route connector(its a spring; goes under that brass push down thingy on the top of the mag)
found here, not the only place you can purchase from however:
Very much worth the money, makes the seal better.
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