johnyew

Added teh UBR stock to my KJ. It involved a disc grinder, steady hands and most importantly, safety goggles as the chips were flying everywhere!! Fully collapsed Fully extended It's not completed yet as I still need to cut the cheekpiece to fit the buffer tube and tap an M6 threaded hole for the UBR buffer tube locking screw.

After spending about 2 weeks, on and off, trying to fix the problem of the slide intermitently unable to fully go into battery, I finally came across the solution. However, because I have all 3 pistols; Kimber(R28), MEU(R27) and a TM 1911, I was able to swap parts between all 3 pistols and locate the problematic part. If you do have the TM 1911 or can find one easily, just swap the complete TM 1911 barrel assembly into the Kimber and you're good to go. No problems whatsoever in 500 rounds of continuos testing. With the exception of barrel bushing which may need minor work with sandpaper to

In my case, temps are 33C/92F, humidity 90+% and my gun internals are all factory parts. If I use Top gas, my FA will not work. If I use 134a, FA works fine. I have manually checked the FA sear and by working the CH back and forth while pressing teh trigger, I can hear the BCG trip the sear. I suspect in my case its a timing issue due to excessive BCG speed unless my understanding of FA operation is wrong. So, right now I'm making a heavier buffer, sourcing a stronger buffer spring and trying them on my gun to try reducing the BCG speed. I will report on my test results.

I'm not sure of the composition of the portable gac canister but it's the cheapest gas around here other than Green gas. There's also straight 134a and R22 which I'm also making adaptors for testing for an alternative to Green/Top gas.

PLease try with 134a gas and see if FA works.

Coal I am working on my own adaptor to use portable stove gas canister.

thanks. I take it you're using straight propane, which, unfortunately is not available here in Hong Kong.

Andrew, I'm interested in knowing your thoughts for not using green gas. Thanks.

Thanks for the great review. How does one diffrentiate between the 2 versions released? Any different markings?

Why not use the elctrical tape fix while waiting for the new rubber band? It's easy to make and should easily last you a day's game.

I'm in the process of machining an adapter to use the portable stove/hot pot butane gas can. Rumor has it that it's between TM 134a and Top gas in terms of power. I can pass one to you when I'm done. Anybody has any theory on why here in HK, FA does not work properly using Top Gas/Propane in our summer weather, 33+C/90%humidity but 134a aka Marui gas works? Is the pressure generated in the magazine hindering the FA cycle? Sirrith is using T-hum's velocity reducer and I am not using any but we both have FA issues using Top Gas/Propane. So could it be excessive carrier/BCG speed or high

Even Armed Forces?

Try checking full auto using Tokyo Marui gas instead of Top Gas. I'm getting the same erratic full auto behaviour using Top Gas and when I tried Tokyo Marui gas, it works perfectly.

That was why I asked if you also made a cut for the nozzle extension. Good news that you found out now and no major damage was done.

Please refer to the attached pic. Cut #1 is for nozzle extension Cut #2 is to control the depth of hop chamber within inner barrel. These are the only cuts needed for the Dboys M4A1 inner barrel. There is no need to drill the insides of the inner barrel. .

That's good because I forsee myself not being able to get RS bodies due to ITAR rules.

Add Dboys M4A1 outer barrel to the DIY list as it does not require boring out the inner diameter to fit the hop chamber. There are only 2 cuts to make; notch for nozzle extension and one of the side walls for depth of hop chamber within the barrel. Both easily accomplished with a Dremel. Travis, BTW, does your PMAG comes complete or do I need to purchase RS PMAG bodies? Thanks.

Ah, okay. Your earlier description only mentioned the notch for hop arm but not the nozzle extension at the bottom.

WDAHM519, Did the barrel already have the notch for the nozzle extension?

Travis, If I'm not wrong, what's happening to him is that the brass ring can't slip back on to both halves of the hop chamber.

I would surmise then that there are a few more differences between serialised and non-serialised guns, including hop bucking.

That's because the channel where the hop bucking fits into is not deep enough. If you have a caliper, you can measure between the stock KJW inner barrel and your TB.

My hop up works about 7 out of 10 shots. I also noticed when adjusting hop is to let it 'settle' somewhat by at least 4-5 shots before making the next adjustment. Certainly the adjustment isn't the same as our AEGs in that the effect isn't always immediate.

The hop bucking has a raised indent where it contacts the arm. If you can make one that has an inverted 'cup' on the arm end and covers the bucking indent, hoping it would prevent any lateral movement of the arm. ETA: Another thought, if you can make the end of the arm with an inverted 'V' cut that stradles the bucking's raised indent, potentially you would not have any lateral movement of the hop arm.

Travis, not sure if you have analysed the hop up arm yet, but if you are able to design a unit so that it does not have any side by side movement at all, then you have another winner on your hands for us KJW owners. For me, I'm contemplating drilling/tapping a hole right above the hop bucking and using a grub screw to make the adjustments and get rid of the hop arm totally.