Snoopy's Initial Impressions on the Tokyo Marui MP7A1 GBB

[Xtcy]

Could someone pm with their email and I'll email the photo of my nozzle? Thanks!

[TheFull9]

Head over to photobucket.com or imageshack.us and upload it, they'll both provide you a link with the appropriate forum code that you can just copy+paste in to your post to show the picture here in the thread.

[renegadecow]

1.3mm does sound like an awful lot. Can you compare how much it travels (opens the valve) to ones on handguns? I know on mine they don't really move all that much which is why under 0.50mm made a significant difference. If on the MP7 it's opening the valve more than what restriction it gets from system itself (sectional area of gas router, nozzle etc) then you wouldn't see changes until you pass that point. Other than shortening the striker itself, you could also try adding gas router shims (under the rubber on the magazine output) with the shim itself having a smaller hole than the opening of the rubber to restrict flow.

Edited November 26, 2012 by renegadecow

[sacairsoftsn00py]

Looking at the valve strker on my XDm, the pin travels a good 3mm or so.

 

I think the striker on he MP7 travels a lot farther to ensure proper functioning on full auto. Pushing the valve farther would ensure that more gas would flow out during cases of cool down. Possibly to compensate the decrease in pressure by increasing the flow. Who knows.

 

This gun...or at least one of em pretty much gets used exclusively for semi auto. I may decide to take out more material. I'm starting to not care about one of em anymore. I've taken 1.5mm's worth of material off of the valve striker and no further decrease in velocity has been noticed. This is true for both 134a gas and propane. If I do other mods, I'll make sure to keep everyone posted.

 

So long as the MP7 cycles fine, I'm good. I could always increase the FPS by modifying the flute valve or by installing a tight bore barrel.

 

I'll double check the whole thing before taking out more material then have a buddy sand it down further for me as he's got better equipment than my dremel, set of files, and sand paper.

[renegadecow]

Your call. Just remember to keep reduction in increments. Once you start feeling significant change, cut down increment size until you hit your mark. Also, should you decide to fix it back to normal, it's possible to rebuild the knocker by adding an appropriate thickness of aluminum attached by a small flat head screw + superglue.

[DrAlexanderTobacco]

AIrsofteire and airsoftguns.ie both sell 144a (same as 134a), but it's a wee bit pricey at 13 a bottle (without postage).

 

If you can get hold of an Airsoft Innovations propane adaptor, it also comes with a Computer Duster adaptor you can use. Duster gas is (IIRC) 144a, and a hell of a lot cheaper.

[AG1212]

If you can get hold of an Airsoft Innovations propane adaptor, it also comes with a Computer Duster adaptor you can use. Duster gas is (IIRC) 144a, and a hell of a lot cheaper.

 

I don't think we get Duster over here, to import it from the UK would be pricey AFAIK.

 

As for breakages, as tooler said, there are several in the country without any reported failures.

[sacairsoftsn00py]

Removed more material. Took a total of 2 mm off of the valve striker.

 

Fps readings with 134a (mags stored in the house where its 71 *F or so)

Chrono values were with toytec .25g bbs.

 

Unmodified MP7:

1. 237.8

2. 238.2

3. 240.8

4. 239.6

5. 235.6

6. 239.2

7. 241.5

8. 242.1

9. 241.8

10. 237.6

 

7rd burst: 14.6rps @ 238.7 fps with .25g bbs

 

Modified MP7:

 

1. 237.9

2. 240.6

3. 244.5

4. 241.5

5. 239.5

6. 243.0

7. 240.6

8. 236.6

9. 234.9

10. 239.4

 

7rd burst: 7.3 rps @ 236.6 fps with .25g bbs.

 

-------------

 

With 134a gas, the fps between the , modified and stock were were virtually nil. The modified MP7 actually had higher fps readings....but not by much.

 

Rate of fire is a different story. Its clear that with the modified MP7, rof changed by a bit.

 

However with a propane charged magazine...the rof went back up to 14+ rps.

 

Perhaps i was correct when i stated that the valve strikers extra length was related to a more reliable full auto firing with 134a (output valve being pushed the extra distance...or for a longer period which increases gas flow to compensate for the pressure drop/ cool down while on full auto). With a higher pressure gas thats less affected by cool down...the extra length of the valve striker isnt required (and may even be harmful to the nozzle cause of extra gas flowing thats really unnecessary to cycle the gun).

 

I can say this with certainty though. The modified TM MP7 does kick noticeably lesser than the stock (unmodified) TM MP7.

 

I will be running with the modified TM MP7 GBB with propane and see how it performs.

---------------

 

 

Side note, Echigoya sent me a complete loading nozzle assembly with the flute valve and everything. I may modify the spare flute valve (trimming off the middle part protruding into the flute valve which i suspect was designed to reduce gas flow towards the bb to decrease the power output of the gun to keep it from shooting over the fps limit in japan) to see if that would increase the gun's muzzle velocity.

 

Unless the weather permits...134a is not a viable option to run the modified TM MP7 GBB reliably as full auto performance with the said gas has become shaky. Propane seems to be the ideal propellant to be used on it at the moment.

[Zereck]

Anyone else had this problem?

Sometimes when I put in a fresh magazine and then pull the charging handle the gun puts the BB in the chamber but doesn't cock the gun. Or when I finished a mag and put a new one in the bolt went forward by itself and again the gun wasn't cocked nor it could be done via the charging handle, without pulling the mag out first and put it back.

This doesn't happen always but could be annoying if it happens in a game for me.

[sacairsoftsn00py]

You gotta pull all the way and release the charging handle. Same deal with kwa mp7.

 

The second part has happened to me on a tm pistol. You have to keep in mind that the bb follower pushes the slide/bolt catch up when the mag is empty. Removing an empty mag and reinserting one could unlatch the catch inadvertently as the catch has a spring pushing it down. Without the bb follower pushing it up...if it gets bumped...it could release on its own.

[Stuey]

Yeah I reckon about 50% (maybe more) of the time when I pull the trigger after inserting my first mag and cocking the gun it doesn't fire. I've missed out on quite a few kills because of it, feels really stupid too!

 

I fix it by dropping the mag slightly, cocking again and reinserting the mag. I'd love to know why it does it though...

[sacairsoftsn00py]

Im sure its related to sear springs. A stiffer recoil spring should solve that particular issue.

 

 

 

[sacairsoftsn00py]

Buddy evened things out for me some on my valve striker (firing pin).

 

I'm thinking that a total of 2.2mm has been sanded from the valve striker.

 

Before another .2mm was knocked down...I tested the TM MP7 and it stuttered on full auto with a propane filled mag (stored at the back of my car where it was at least 50 degrees Fahrenheit). Im guessing it was maybe doing the 7 rounds a second or less that I saw on a mag wtored at 71 Fahrenheit with 134a.

 

Semi auto on the other hand functioned without a hitch. With extra material knocked out...the TM MP7 with the modified valve striker definitely has less recoil than the stock one. It should be healthier for my nozzle in the long run.

 

 

Thanks for finishing the valve striker for me Dagger

 

I have yet to chrono my mp7 again after the mods. Will need to test it with a propane charged mag stored at 71 degrees Fahrenheit.

 

If the fps drops entirely too much for my liking...I have a modified flute valve on hand. Ill post photos if/when I decide to play around with the flute valve settings and again keep everyone posted.

Edited November 28, 2012 by sacairsoftsn00py

[sacairsoftsn00py]

71 degrees Fahrenheit. Propane in mag and .20g BBs. I was shooting 332-342 FPS. Full auto rate of fire was chronoed at ~8RPS. Again as noted earlier...recoil has been reduced. Semi auto firing cycling is perfect. FPS output is acceptable.

 

Unless the modified flute valve is installed, no further modifications internally will be done to my TM MP7. I feel confident that the nozzle will hold up just fine.

 

Edit:

 

 

Stock flute valve...notice the post running through the tube. I suspect it was cast that way to restrict gas flow. TM GBB pistol flute valves do not have that.

 

 

Buddy knocked that post down by about 5-6mm. I then tapered it as shown. This is how Marui GBB pistols are normally set up. This should allow for better gas flow towards the bb.

 

Haven't tested the modified flute valve.

 

Edited November 28, 2012 by sacairsoftsn00py

[sacairsoftsn00py]

60*F. Gun was shooting around 345-355 with propane. Shot about 300 rounds tonight. Semi auto functioned flawlessly with the modded valve striker. MP7 was dead accurate.

 

 

Nearly shattered my optics. That lense protector did its job but didn't hold up. Ill get it replaced with one of a different material.

 

Edit:

 

Loading nozzle held up like a true champ this time around.

Edited November 30, 2012 by sacairsoftsn00py

[sacairsoftsn00py]

 

Video of a busted nozzle...

[lightemup99]

Is that the second nozzle you have broken or just more evidence of the first one?

[NonEx]

I think that is someone else's video ? "Video of a busted nozzle..."

 

To be honest I can't remember last I heard of these many catastrophic failures this shorltly after release, certaintly not for a TM product. Feels like production problems

[sacairsoftsn00py]

Ive only broken one nozzle. So far the TM MP7 that I've modified has been holding up on propane.

 

Video I posted was someone elses.

Edited December 3, 2012 by sacairsoftsn00py

[Inari]

How many properly documented? I wouldn't be surprised that there are a lot of breakages due to the fact TM have never done this kind of product before, so it is new territory for them. I would question how many there actually are though.

 

My own arrived this Friday, and fielded it all day on Sunday putting through a close to 500rds on Green Gas, without as much as hiccough. Cool down was non-existent until the very last game (17.30-ish) at circa 2 degrees Centigrade, so needless to say I'm impressed.

 

Similarly, this is the most fun I have ever had with an airsoft gun...period. It was such a joy to use, that I immediately thought to myself "I will run this into the ground, and then I will buy another one" - it is that good.

 

PLEASE NOTE: I live in Ireland; running TM's on Green Gas here is the virtual equivalent of 134a in Japan...roughly speaking. Considering the fact that Snoopy had a nozzle explode on Green Gas in the US, I would say for now, stick to 134a unless your climate is mighty cold

[sacairsoftsn00py]

Exactly. If its warm...use 134a. If its cold enough...green gas. A lot more people outside of Japan probably run these things on green gas/propane resulting in nozzle breakage.

 

If you don't care too much for full auto, sand down the valve striker like I did. It significantly reduces the recoil (which I believe is due to the output valve not releasing as much gas when it fires...less gas...less blowback force...just enough to run the system). It will be kinda like running 134a....just without the cool down properties that gas has. Downside...is loss of 14-15 rps on full auto. You will be stuck with 7-8 rps per burst. I have not tried a mag dump on my gun as I don't feel like doing one right now. If I ever decide to do it...yup. yiu guys know I'll post my findings.

 

Thanks to renegade for the tip on sanding down the valve striker/ firing pin.

[AG1212]

Inari, where did you order yours from? And how much did it cost including taxes (if you had to pay)?

 

What happened to that import ban they were implementing...

[Inari]

Inari, where did you order yours from? And how much did it cost including taxes (if you had to pay)?

 

What happened to that import ban they were implementing...

Got it from EHobby - tried Redwolf twice, but they aren't shipping it into Ireland for some obscure reason

 

Import ban exists, and is on legislation but is not enforced (and cannot be until retailers licenses are introduced) - they are clamping down big time at the moment, so you need to ensure anything you import is under 1 joule, as more and more packages are being stopped and destroyed

[sacairsoftsn00py]

 

My hip pouch used to have shock cords and tabs for retention.

 

 

 

Made these ones about 5mm shorter than I wanted so I had to cut down part of it at the bottom. The mag lip (midway through it) sits flush on top of the top most part of the kydex.

 

 

 

Next kydex inserts were 5mm longer. As a result, the feed lip of the mag does not come into contact with the bottom. The kydex surrounding it protects it from possible damage. The lip midway through the magazine sits flush against the kydex so when the mag gets put in...it wont wobble around as much. Now I just have to get a chest rig done.

Edited December 8, 2012 by sacairsoftsn00py

[DarkLite]

Another indoor CQB game today. Ran the TM MP7 pretty hard - fired a total of 28 mags through it in 4 hours. Followed it up with some full auto mag dumps to unload at the end of the day.

 

Not a single hitch, though now I am definitely itching to put a tightbore and a W hold hop-up rubber in there...