A little problem with my green gas...

[Vampyre (Immortal)]

It is truly an awesome gbb smg. Personally I plan on getting one just for the cool factor, it would look awesome on my mp7.

[rodrick]

Ok, though it does not have to do with Gas, I still need some help with this.

You see, I am trying to clean out my MP7 because it would not stop firing after the magazine was empty earlier today. I am following a video I found on youtube


And at about 2:36, he removes the stock along with the bolt carrier. For mine, that is not happening, and I am scared that I broke my expensive new MP7 before I even got to use it!

[Fugazi]

Many gas guns continue to fire when they're empty, sometimes it's a sign that the magazine (or wherever your gas reservoir may be) wasn't charged enough, and not enough gas expanded to lock the bolt back. And some guns just continue to shoot, whether or not they're dry-firing.

Now, is it continuing to shoot WITHOUT pulling the trigger? Because then it becomes a safety issue, rather than a convenience issue.

[rodrick]

Mar 20, 2011 5:29:28 GMT -5 Fugazi said:

Now, is it continuing to shoot WITHOUT pulling the trigger? Because then it becomes a safety issue, rather than a convenience issue.

Thank God no for that, however, The fact remains that the guts aren't coming out of the gun and have somehow got detached from the Cocking handle.

[Vampyre (Immortal)]

If your problem is that the stock slides out and the parts aren't sliding out too, it is because when disassembling you do not need to depress the stock release levers. All they do is release the stock. Once you get the parts out you can reinstall the charging handle by finessing it in. Check the charging handle to see if it wasn't damaged by comparing it to the illustration of it in the parts diagram.

I agree with Pariah, you might not be filling the mags all the way up and since it is still cold in Michigan the gas doesn't expand as fast. Also, if you are trying to fire all the bbs in the mag with one trigger pull the bolt probably won't lock back when the mags empty.

Also, in that video the guy did a few things that will cause a big problems in the future. I know of him on the KWA Forums and he had to send in his mp7 because of the hop-up issue. He even has a video about what they replaced.
I believe these problems he had were caused by his maintenance practices.

Do not put oil directly into the bolt itself and the outlet valve in the mag, the excess oil will mess with your hop-up and the piston in the expansion chamber.
Green Gas will lube these areas anyway.
All you need to do is clean off the outside of the bolt and the inside of the inner frame that the bolt rides in. Spread minimal amount of oil preferebly grease along the inside of the inner frame.

Predominately the mp7 should be clean and dry. The green gas will lubricate everything that you need it to anyway.

[Post Edited]

[triggs]

Proper maintenance is always necessary.....moving parts should be oiled or greased depending on their function. Bolt carriers for instance require grease (100% silicone) to move freely. Rubber o-rings require silicone oil (normally green gas is enough to keep them moist, but occasionally they still require additional silicone to keep a seal).

This is also to be stressed that due to the amount of grease and oil in a GBB or any firearm, regular maintenance is required. A.K.A. it must be cleaned at least ever couple games (days not individual games). Otherwise the oil or grease will attract dirt and grime and gum up moving parts leading to malfunctions. It's generally a good idea to clean major parts once a week to ensure consistent and reliable function.

KWA's seem to be more forgiving of improper maintenance than other companies I've had, however, it's better to properly maintain than to abuse them. Doing so will increase the lifetime of the complete rifle.

It is worth mentioning however there is a fine line between over lubing and under lubing things. If it moves it should be greased/oiled to reduce wear and increase life. However, over lubing will gum things up faster, as well as attract dirt/grime faster and then you'll have to clean it that much sooner.

Soooo have another -1 for more bad advice. I really hope you don't treat your stuff like that Vamp.....it's never going to last.

P.S. Proper maintenance on my KWA M9PTP and it is the most reliable pistol I've ever owned. 3 years and going strong as the day I bought it.

[rodrick]

OK, just to update everyone, I fixed the MP7 so that it is once again functional, but I just found out that, even when there is no BBs in the gun, the charging handle will still act as though there is a round, jolting back to its origional position, where then I have to pull the trigger to releace spring tension.

I am pretty sure it is just a lube problem which I will fix in a new days (If not moments) time.

[triggs]

Ok very confusing..... but I think I get what you're saying.

A note about GBB's
On any GBB or GBBR you can pulling the charging handle/slide (on pistols) and it will lock the hammer in a firing position. It also pulls back the loading nozzle that actually pushes a BB from the mag into the hop up chamber.

When you pull the trigger the hammer hits the gas release valve on the mag (indirectly through a series of parts). The gas is directed through the loading nozzle propelling the BB down the barrel. At the same time the gas is also used to push the loading nozzle back wards allow it to load a new BB and cocking the hammer back without you having to physically pull the charging handle.

When there are no BB's left a piece in the mag pushes the slide lock (on pistols)/bolt catch (on rifles) up locking the slide or bolt carrier open. Insert a new mag hit the slide release/bolt catch and off it goes again.

Ya know I can't find a cool gif as an illustration.
This about as close as I seem to be able to find. It gives a rough idea of how it works
Although obvious airsoft does not use shells
www.encyclopedia.com/video/WsCIbvQ8oVI-colt-1911-firing-animation.aspx

[Vampyre (Immortal)]

What I am explaining is the proper way to maintain the MP7. It is an airsoft gun that does not like to be over lubed and it likes minimal lubing. Yes the action and moving parts should be lubed, but dripping lube inside the bolt and the magazine outlet valve is just causing a ton of over oiling. With the Mp7 Parts #30(main seal) and the hop up bucking need to remain free of excess oil for the gun to function properly. When these parts are over oiled they swell, when the main seal swells the action doesn't function properly and when the hop up bucking is over lubed it also swells and causes catastrophic jamming.

I know you don't like me or what I say triggs, but I know what I am talking about when pertaining to the Mp7 and it's proper maintenance.

[Edited]

[triggs]

Big difference between under lubing, lubing, and over lubing.

No where is it suggested to over lube in fact I specifically stated not to over lube. You however mention specifically to UNDER lube critical parts. Which WILL cause the rifle malfunction and break sooner than needed.
I also specifically stated GREASE should be used for certain parts not OIL which does cause jamming issues. I apparently do need to explain grease is thicker than oil and won't travel to other parts like oil which is thinner.

Pay attention. I thought you might know better after being proven wrong time and time again by multiple members of MIA. Not by me but other members clearly more experienced in rifle upgrading and maintenance.

Hahaha you make me laugh. It's not that you're not liked. It's very simply that you are too inexperienced, and under knowledged to be giving advice to people on something you clearly don't understand. This is blatantly obvious to every gun tech here. And I'm not the only one that has proven you wrong time and time again.

[rodrick]

Mar 20, 2011 19:31:33 GMT -5 triggs said:

Ok very confusing..... but I think I get what you're saying.

A note about GBB's
On any GBB or GBBR you can pulling the charging handle/slide (on pistols) and it will lock the hammer in a firing position. It also pulls back the loading nozzle that actually pushes a BB from the mag into the hop up chamber.

When you pull the trigger the hammer hits the gas release valve on the mag (indirectly through a series of parts). The gas is directed through the loading nozzle propelling the BB down the barrel. At the same time the gas is also used to push the loading nozzle back wards allow it to load a new BB and cocking the hammer back without you having to physically pull the charging handle.

When there are no BB's left a piece in the mag pushes the slide lock (on pistols)/bolt catch (on rifles) up locking the slide or bolt carrier open. Insert a new mag hit the slide release/bolt catch and off it goes again.

Ya know I can't find a cool gif as an illustration.
This about as close as I seem to be able to find. It gives a rough idea of how it works
Although obvious airsoft does not use shells
www.encyclopedia.com/video/WsCIbvQ8oVI-colt-1911-firing-animation.aspx

[Vampyre (Immortal)]

I was talking about the dan kid in the maintenence video sugesting to drip oil into the Bolt of the gun. This will cause over oiling inside it and will cause problems.

I think I might of mixed up my terms hold on I'll edit my original post and it will probably make more sense.

I'm really sorry about this, it is probably why you reacted the way you did. Can you please read the post I made again to see if it makes sense to you?

[triggs]

Ah that's quite convenient.

The piston sticking forward in the hop up is not normal. And it could be a couple things really.
1. The loading nozzle (the part sticking forward is what loads the BB's into the hop up) is indeed under lubed and is sticking.
2. It's dirty from grime/dirt (grime can come from paint wearing off moving parts when they are new) and needs cleaning as well as a re lube.
3. The nozzle is catching on something. Experience with KWA however makes me assume one of the first two.

As for the charging handle not locking the bolt back.
For the bolt to lock back an empty mag MUST be in the gun.

Hmm I think that's clear?

P.S. your room is a disaster

EDIT Vamp ok you're terms are fubar alright. so we'll go off of KWA part numbers
store.kwausa.com/images/diagrams/gbb/mp7_parts.jpg

Part #31 is what Dan is trying to explain in his video. This particular seal should always be clean and well oiled. The loading nozzle (part #23) often sticks (the issue rodrick is having for instance) due to dirt/grime or not enough oil. I prefer to pull the loading nozzle partly forward to expose the seal (part #31) and drip a LITTLE oil on it directly, dripping oil in the nozzle his way just misses the seal altogether and doesn't actually accomplish anything(not a lot just a drop will do). Dan also appears to recommend lubing parts #27 and #28 which is the nozzle jet valve. It's unneeded as the silicone in green gas will do it for you, but it won't hurt anything.

EDIT2: woops started writing about a M4 GBBR

[Vampyre (Immortal)]

I was mixing up the terms bolt and bolt carrier, they are completely separate and the whole time I was arguing with you I was thinking I was referring to the bolt itself, but I was saying a completely different thing. All I did was change a few terms.

But, putting oil on the rocket valve will cause it to spit oil into the barrel and onto the hop-up bucking causing problems. It will only cause harm in the long run when the hop-up swells and causes jams. Other than that what he suggests is fine except dripping oil in places instead of carefully applying it, all that unneeded oil will just collect debris and foul the action. Being careful with where oil is going in the bolt is very important with the mp7 because taking apart the bolt assembly Part #23-37 to clean everything is a major hassle and many people end up making disastrous mistakes.

Danph77 actually ran into the hop up issue long before it happened to me. I think it was because of him oiling areas that aren't suposed to be oiled.

Anyway triggs is right. When you pull the charging handle back the bolt will not lock unless you have an empty mag loaded in the gun. When charging the gun when there is an empty mag loaded the bolt will lock back and the charging handle will stay back too.
That is completely normal with the mp7. Also, with the mp7 there is no way to make the bolt lock back without a empty mag loaded.

With the feeding nozzle sticking issue try to pull the charging handle back a little faster, sometimes it will stick a little when it is not pulled back fast enough, the return springs in the loading nozzle(cylinder) are rather weak and pulling it back halfway will cause the nozzle to get stuck a little.

Apply a little oil around the loading nozzle and rack the bolt back normally a few times and it should solve the problem. Test to see if it worked by loading an empty mag and pulling the charging handle back to lock the bolt and you should see that everything is where it is suposed to be.

[triggs]

The KWA MP7 doesn't have a bolt so you can't really confuse it. You are however confusing the bolt with the loading nozzle/gas cylinder. The bolt carrier, or rather the bolt carrier group (BCG) to which the nozzle is attached to is a complete assembly often referred to as the bolt.

Indeed oil in the nozzle (and thus the jet valve) will spew out into the hopup and barrel. However, the only problem it will cause is dirt accumulating in the barrel (leading to possible jams) or wildly inaccurate shots due to the hopup not being able to get a solid grip on the BB. When the silicone oil first starts in the hopup/barrel it will just fire wild inaccurate shots. However, as dirt and grime accumulate everything builds up. This can lead to inaccurate shots, misfeeds, jams and other related malfunctions. This is easily rectified by simply using the cleaning rod supplied with most rifles.

There also isn't a real need to disassemble the BCG, just a quick wipe down and re oil will be more than enough. So parts 23-37 shouldn't be needed to be taken down anyways.