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MP7 bucking question


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#1 VanHalen7884

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Posted 28 January 2013 - 05:26 PM

I am planning on buying a mp7 before they are sold out now that they're discontinued, but i found in my research that the bucking swells and it is a very common problem. I really dont want to deal with that and i hear green gas can do it too, so would running propane and adding a drop of r/c shock oil every 10 mag fills keep the  ucking from swelling? Or is there no way around it?

#2 gcw360

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Posted 28 January 2013 - 05:43 PM

Hi VanHalen 7884 - Welcome to the KWA Forums.  Glad to hear Diamond Dave's back with the band.  Anyway, I've used GG in my KMp7 exclusively for quite some time with no bucking swelling issues.  If you can, I would go that way.  Regarding the recipe for the correct amount of silicone oil, I'll leave that to another member.

#3 Outlaw1995

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Posted 28 January 2013 - 06:06 PM

Welcome to the forums Vanhalen. PANAMA! lol just had to.

I've never heard of an instance where the hop up bucking would swell due to using green gas. I've only seen it happen when people run propane and add lots of silicon oil. If you have to run propane, I'd recommend using green gas for the first 45 days of ownership, so your warranty is good, and then make the switch if you have to.

If you have to use propane, I'd recommend putting very little lubrication inside the gas itself, and making sure to keep a rigorous cleaning schedule to ensure it's always clean after shooting. Keeping an MP7 cleaned properly is a harder task, as getting to the inner frame is somewhat difficult, and should not be done on a regular basis. But maintaining moving parts like the bolt should be sufficient for most cleanings...

#4 Chuck S

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Posted 29 January 2013 - 04:27 AM

The MP7A1 is not "discontinued."  It's just no longer marketed or available from KWA-USA, you have to buy it from Umarex.  Actually you don't buy from either but from an airsoft retailer who can no longer buy it from KWA-USA etc.

-- Chuck

#5 Kurama

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Posted 06 February 2013 - 08:43 PM

I had a swollen bucking on mine when I bought it second hand, quite honestly it isn't a very big deal. The first time I took my gun apart, partly to learn how, and partly to fix it, it took me a couple hours. The second time I went in after I figured out what the problem was and had the new bucking, it took me less than 20 minutes to strip down the gun to the barrel and change the hop-up. Unless you plan on adding silicon oil straight into the propane can, you should be fine. Possibly just a little drop/bit of a spray every like 4-5 mags or so and you should be good. (With regular cleaning as said before), If you lube the inside of the gun on the moving parts, be sure to wipe off the oil from before so that it doesn't start to accumulate and make more problems than benefits from your time.

#6 Icurblud

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Posted 07 February 2013 - 09:06 PM

View PostKurama, on 06 February 2013 - 08:43 PM, said:

I had a swollen bucking on mine when I bought it second hand, quite honestly it isn't a very big deal. The first time I took my gun apart, partly to learn how, and partly to fix it, it took me a couple hours. The second time I went in after I figured out what the problem was and had the new bucking, it took me less than 20 minutes to strip down the gun to the barrel and change the hop-up. Unless you plan on adding silicon oil straight into the propane can, you should be fine. Possibly just a little drop/bit of a spray every like 4-5 mags or so and you should be good. (With regular cleaning as said before), If you lube the inside of the gun on the moving parts, be sure to wipe off the oil from before so that it doesn't start to accumulate and make more problems than benefits from your time.

What did you use to get the 2 pins out , in order to pull the inner barrel out.   I TRIED TAPPING the out but the didn't move.  What kind of buking did u go with

#7 kwaispro727

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Posted 08 February 2013 - 06:51 PM

Are there any buckings for the Mp7 that are more resistant to swelling?

#8 Outlaw1995

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Posted 09 February 2013 - 09:30 AM

Apparently this tight bore barrel which gives users a HUGE fps/accuracy/range boost comes with the renowned blue bucking. It is according to some users more resistant to swelling from excess silicon oil versus the stock KWA one.

http://shop.ehobbyas...-gbb-363mm.html

Ehobby used to sell the bucking by itself, but now I can't find it.

#9 Kurama

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Posted 11 February 2013 - 06:21 PM

View PostIcurblud, on 07 February 2013 - 09:06 PM, said:

What did you use to get the 2 pins out , in order to pull the inner barrel out.   I TRIED TAPPING the out but the didn't move.  What kind of buking did u go with

I have a set of drift pins, but the first time I got the pins out I used a hex key and just tapped on it with a hammer a little bit, I just went with a replacement bucking from the pro shop, nothing fancy. I figure that if it only takes me less than an hour to change one out, on the off chance I mess up again and swell the bucking, it's five bucks and a bit of time to get to know the guns internals better.

#10 Chuck S

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Posted 12 February 2013 - 07:33 AM

That barrel is 14" long.  Gonna stick way out the end of the MP7A1.  Gas guns very often benefit from longer barrels just like cartridge guns often do as they both use more of the expanding gas.  There's a point of no gain, however.

-- Chuck




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