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1, Let me Ask you Why Didnt you Just use a PDI 7 Inch Hi Capa Barrel? All the Specs are the Same as the TN Correct? Since it Basically a GBB in a Different Body

 

2, Can you Explain Greg if I am going in the right direction etc.

 

O Btw I think I found a Guide Correct Me if I am wrong

 

http://www.redwolfairsoft.com/redwolf/airs...il?reviewID=234

1, Right. Super. When I ask for ideas on what barrel to use, no one replied. Now I've found a solution, you all come out of the wood work with 'why don't you use this?' & 'why don't you use that?' :angry:

 

Only kidding. ;) I don't think this would be a good choice for 3 reasons. First off, I think it's too short. It's made for a 7" slide, it's not 7" long. If made for a Marui system, the hop set up is completely different & would require as much work as an aeg barrel. & like the aeg barrel, it's diameter is .5mm too big. So it wont fit in the outer barrel without a load of work.

 

2, Nice take down guide. If only I'd seen that before doing the work! :rolleyes: As said, the procedure is adequately explained, pictorially, in the back of the manual. No sweat. ;)

 

 

Greg.

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Just replaced the stock barrel with the 200mm, TN auto, barrel, in another pair of gas MP7's.

 

All chrono figs are with a .2 @ approx 19C.

 

The first was a KSC which chronoed 280 before & 310 after. The second was a KWA which was 360 & chronoed 410 after.

 

 

Greg.

Edited by greg
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Generally speaking, spring/piston/cylinder operated guns only expel just enough gas to force the BB out of the barrel while the gas is expanding. Gas guns are a lot more "inefficient", belching out a big cloud with every shot. that's why anything that keeps the BB in the barrel longer, like a longer barrel or a heavier projectile, allows more time for the gases to expand behind it and increases the energy output of the gun.

 

It's not an exact science, but suppose your AEG puffs out x amount of gas (the volume of the barrel) plus maybe 10% for good measure. You decrease the diameter of the barrel, wasting maybe 5% less gas, and you get a corresponding increase in FPS. Now I'm guessing the average gas gun spits out 300% or more of it's barrel volume (once the gas fully expands) with each shot, so that 5% gas savings translates to a much bigger boost.

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Yup, that & the fact that with gas, you are dealing with an 'expanding', compressed gas. In an aeg, the air in the cylinder, is forced out, but never really compressed, as the bb moves out of the barrel fairly easily.

 

Also, consider the relatively short barrel length we are dealing with. 160mm is tiny, the gas released comes out very quickly & will fill a longer barrel of much greater internal volume.

 

 

Greg.

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Question - where are most of you guys getting extra mags? I noticed the KSC one is a bit more expensive than the KWA ones, but I'm making an order from DenTrinity soon and am willing to settle for a KSC one if it can handle GG/PP.

I ordered & got 2x40rnds from Den.

 

It was marked KSC Japan. Do not use with hi-power gas etc. I've been running it on green. No probs. I think the warning is just there because of the Jap power limits.

 

 

Greg.

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I havent had any issues running my original KSC mag on green at all. I am having real difficulty ordering more mags for it. I recantly placed An order for 8 mags at wgc when they where in stock and then they went out of stock and they tell me they cant get any more at the moment from KWA. I begrudge having to pay another $20 each for a product that is the bloody same from KSC.

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I got an NPAS and two spare mags on the way from eliteshootingcentre (last two - sorry!). 45 GBP apiece, cheaper than importing the KSC JV mags from HK, not quite as cheap as a bulk order of TW mags would have been, but no where had them in stock anyway.

 

Mp7 is brilliant fun to shoot, used up a 3/4 full can of propane on it in 2 days of plinking (I have now run out, waiting for delivery of 8 more cans :D ), few things to note:

 

When I was plinking indoors, at about 8m I used up the last of my .2g BBs (I think they were AIM, not sure though). Didn't like them a great deal on full auto (fine on single shot), occasional misfeeds (2-3 per mag). Was absolutely perfect on Guarder .28g however.

 

There were a lot of plastic shavings around the mag lips/loading ramp, white and presumably from the BBs. Once I cleaned it all off and kept shooting I didn't see anymore shavings appear, so I can only assume it was some kind of initial problem with the magazine that has worked itself out with use.

 

Indoors (about 15°) I could get 4 full mags of BBs out on single shot on one charge of gas, 3 full mags on mixed single shot/burst fire. I didn't do any full auto mag emptying however.

 

Outdoors (hovering around freezing/0°) range appeared very good whilst I was setting the hop (with .28g), certainly on par with my ICS M4, couldn't get exact values on range as it started to snow and I couldn't see anything anymore. Gas efficiency at this temperature: mixed full auto/single shot 2 full mags bolt locked back but shots felt weak toward the end. Single shot only, 2 mags, then halfway through the 3rd mag shots started getting weak. Finished off the 3rd mag but bolt did not lock back.

 

I did find whilst setting the hop I had one setting where it was good but just ever so slightly not enough hop, then the next click was too much. Irritating, but the range was still very good. Hopefully I can sort this out with the NPAS, adjusting the FPS to suit the hop settings available.

Edited by kruck
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Hmmm...Finally after 20K rounds, my KSC MP7 taiwan is now showing some erratic performance. Although accuracy and FPS remains when it is working, it is now beginning to fail in shooting the BB's on the second reload of the mag. As long as the Mag is fully charge, it will shoot without a problem as long as it is in semi or short auto burst. But if you will shoot it in full auto, after half of the BB's has been shot, the gun will no longer shoot the remaining BB's out, but will continue to blow back thus feeding multiple BB's in to the chamber. So when you point the gun down, the BB's will just fallout of the barrel. Any inputs? I tried replacing the entire blowback housing with my spare KWA MP7 but to my amazement, the problem continues. Then when i replace it back on my KWA and use the used mag on it, it will shoot perfectly.

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Hmmm...Finally after 20K rounds, my KSC MP7 taiwan is now showing some erratic performance. Although accuracy and FPS remains when it is working, it is now beginning to fail in shooting the BB's on the second reload of the mag. As long as the Mag is fully charge, it will shoot without a problem as long as it is in semi or short auto burst. But if you will shoot it in full auto, after half of the BB's has been shot, the gun will no longer shoot the remaining BB's out, but will continue to blow back thus feeding multiple BB's in to the chamber. So when you point the gun down, the BB's will just fallout of the barrel. Any inputs? I tried replacing the entire blowback housing with my spare KWA MP7 but to my amazement, the problem continues. Then when i replace it back on my KWA and use the used mag on it, it will shoot perfectly.

 

 

Put a rag in your cleaning rod and soak it is silicon oil. Let it sit in the hopup rubber overnight. You can paint oil in there with a Q-tip etc. also. I know this sounds the opposite of what you want on the hopoup rubber but it will sort the feed issue.

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Put a rag in your cleaning rod and soak it is silicon oil. Let it sit in the hopup rubber overnight. You can paint oil in there with a Q-tip etc. also. I know this sounds the opposite of what you want on the hopoup rubber but it will sort the feed issue.

 

Allright! which one is it? Lube the hop-up, or don't lube the hop-up?

 

Like Panteras, mine was doing that too. My problem was with the hop-up swelling from absorption of lube I believe. I took it out, soaked it in acetone (which on another forum, said that was a no no), and it worked!

 

It does it once and a while again, and I believe it's because my propellant is a little weak (I have a KWA version that's sposta be run on greengas, but I'm using Tetra. When I get some GG, and some BB B_stards to test, I'll know know for sure.

 

Is there a hop-up expert anywhere in the world, that can answer this problem once and for all?????

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hop up rubbers tend to be finicky about lube, in my experience. they want just the right amount to do well.

 

would assume that in tropical and humid environments like that in the philippines, the lube tends to dry up faster and collect dust as well. wouldn't know about colder climes but i imagine they wouldn't dry up but would congeal instead -- meaning the lube would be in small clots and not spread out through the rubber.

 

spraying a bit into the magazine each time i load it with gas works well with my GBBs. i hardly ever lube the hop, except when i do a maintenance cleanup of the gun. whenever i do that, i clean the hopup chamber with q tips first to get rid of any dirty oil and whatever dirt it has collected. after that, a fast swab with another q tip sprayed with silicon oil works well till the next maintenance check.

 

the swabbing works well with my aegs too. of course, i also spray silicon oil into every new bag of bbs. ;) i never squirt silicon into the bb feed channel as the manuals suggest.

 

cheers,

zT

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I ordered & got 2x40rnds from Den.

 

It was marked KSC Japan. Do not use with hi-power gas etc. I've been running it on green. No probs. I think the warning is just there because of the Jap power limits.

 

 

Greg.

 

My 2x 40rdrs I got from DenTrinity were marked KSC Japan also. Not had a chance to try them out yet (MP7 should be back with me by the weekend yippee :D ) but loaded em up with abbey predator to keep em tight ;)

Also got me a readyfighter #23 nozzle, just in case my original blows up ;)

(and 4x #24 springs, just in case..)

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My 2x 40rdrs I got from DenTrinity were marked KSC Japan also. Not had a chance to try them out yet (MP7 should be back with me by the weekend yippee :D ) but loaded em up with abbey predator to keep em tight ;)

Also got me a readyfighter #23 nozzle, just in case my original blows up ;)

(and 4x #24 springs, just in case..)

Yeah, nice pre-emptive there with the spares kit. :D

 

Thus far, these have been the only reported failures.

 

Remember, if you have to install the readyfighter nozzle, make sure to 'carve', the retaining slots into the spring retaining lugs.

 

The first time I did this, I didn't make them deep enough. Inevitably, one of the springs popped off & got chewed in the blowback unit. Now the slots are deep enough, it has not happened. ;)

 

 

Greg.

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Good news. I tried the "acetone " solution and it did work on my gun. Tried 2 mags in full auto and no problem. Will post on sunday again after i use it in a skirmish if it really was solved.

 

By the way, whe i tried to install that ready fighter nozzle i noticed that the inner diameter is a little bigger than the stock unit. Because when i try to move it, there was no friction whatsoever between the piston rubber and the inner side of the nozzle. unlike with the stock nozzle there is a little resistance. Is this normal with your ready fighter nozzle?

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By the way, whe i tried to install that ready fighter nozzle i noticed that the inner diameter is a little bigger than the stock unit. Because when i try to move it, there was no friction whatsoever between the piston rubber and the inner side of the nozzle. unlike with the stock nozzle there is a little resistance. Is this normal with your ready fighter nozzle?

The Readyfighter unit is designed to replace the KSC Japan version ONLY. This is a particularly thin walled unit designed to break, if used for any length of time on green.

 

The reciprocating cup for this model, is a different size & the Readyfighter unit is specifically made to match it.

 

If you are trying to put the ready fighter unit into any other MP7, you will have to replace the cup, with the appropriate part.

 

 

Greg.

Edited by greg
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I'm after a quick bit of advice...

 

I've been offered an KSC MP7 which has been upgraded by a shop with a readyfighter nozzle, not seen action in the field but has been used. It will come with 6 extra 40rd mags making a total of 7. The guy wants £550 for the lot.

 

Is that a bit steep considering I picked up my first one for about £240 (stock condition) with one mag. Makes it £250 for the gun and £50 a mag. I know they are rare but there's a limit...

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