stickyittoyou Posted October 15, 2009 Report Share Posted October 15, 2009 So reading this thread persuaded me to join the kjw m4 club. Sounds like by far the best option without spending thousands for decent m4 gbb. Had a few question though. - could anyone recommend a decent and cheap standard ris rail kit for this gun? (ideally with standard handle thrown in) There seem to be so many out there! - and i'd be very interested in the fps adjuster as i've seen mentioned earlier, as i live in the uk so wouldn't be able to use the gun on site till i got it under 350. I've ordered mine from uncompany. Once it arrives i'll hopefully be able to contribute to the glowing reviews! i have a kjw berreta and its never let me down yet. UTG RIS rail, direct bolt on. Quote Link to post Share on other sites
Kai_Wolf Posted October 15, 2009 Report Share Posted October 15, 2009 The UTG Regular RIS is hard to find now as it is out of stock in most places, but their Freefloat RIS works like a charm. It is on mine now and is really solid. No wobbling or moving whatsoever and took about 10 minutes or less to put on. Quote Link to post Share on other sites
wotty33 Posted October 15, 2009 Report Share Posted October 15, 2009 thanks for your help guys! i found a cheap g&p rail setup, so i think i'll go with that and post some pics when its done. Cant wait to try it out! Quote Link to post Share on other sites
SwatMP5man Posted October 15, 2009 Report Share Posted October 15, 2009 (edited) Welcome to the club, i guarantee you won't be disappointed. Not sure where you ordered from, but wouldn't it have been cheaper to get spare mags at the same time as the gun, i did and found although the extra 5 mahs cost $180 it only increased shipping by $10 to the UK. Anyway, i hope your KJW M4 gets to you quicker than mine did 3 weeks 4 days (UK Customs) and enjoy. Also parts list for my M4 on previous page. DBoys KAC RASII, ACM Fully trademarked red dot ACOG, KAC Rail covers, and not in picture but now attached a Troy BUIS. Hoping to get a PEQ15 and a red laser module to put in it eventually. Edited October 15, 2009 by SwatMP5man Quote Link to post Share on other sites
elrey Posted October 16, 2009 Report Share Posted October 16, 2009 Guys--please keep the discussion limited to the rifle. People will be reading through this thread for months, so we don't need irrelevant junk to take the place of solid information. Thanks. Edit: I guess this also means that you can leave out the "I finally bought one, yay!" posts. We know you're excited. This is a review thread, not a club. Quote Link to post Share on other sites
Apache137 Posted October 16, 2009 Report Share Posted October 16, 2009 (edited) I think it should be allowed to post a picture of your gun and what you have on it, for the sole reason of letting people know what fits and works... oh well, keep the durability reports coming. Edited October 16, 2009 by elrey There's nothing wrong with doing that, but if you just want to post photos, do it in the picture section. Quote Link to post Share on other sites
t_hum Posted October 16, 2009 Report Share Posted October 16, 2009 Raven1 and I got together last night and did some testing of the o-ring piston vs the stock setup. Tests were conducted using propane fuel and shot at 1 second intervals. Stock Gun Initial magazine temperature : 86.7 deg. F Ambient temp: 87.0 deg F Gas efficiency: 130 shots Gun w/ o-ring Initial magazine temperature: 82.6 deg. F Ambient temp: 84.0 deg F gas efficiency: 125 shots Bottom line is, it works perfectly. Gun feels and shoots just like stock but without the chance of having the cup seal go out. Long term testing is in the works and should be completed by this time next week. Sorry for the long wait! Quote Link to post Share on other sites
wdahm519 Posted October 16, 2009 Report Share Posted October 16, 2009 I'm assuming by O-ring, you mean the new piston you are making? If so, then I'll definitely be waiting for you to produce this so I can buy one! Quote Link to post Share on other sites
t_hum Posted October 16, 2009 Report Share Posted October 16, 2009 Yes, Im referring to the o-ring piston. Sorry for the confusion. It is technically ready but I'd like to wait until velocity reducers are finished so people can save on shipping. Quote Link to post Share on other sites
Kai_Wolf Posted October 16, 2009 Report Share Posted October 16, 2009 (edited) That sounds Awesome T hum, I cant wait to get one from you. Also, I had a question. My full auto studders irregularly sometimes and I think it is beacuse my cup seal has tears here and there in it. Does that make sense or would that come from another part? Will the O ring Piston help with keeping the shots regular? My Cup seal is jagged on the edges and I think it is the cause as when I first shot the weapon on auto, it was very regular, but now if the trigger is held down, it studders for a few moments, and then goes to a regular pattern again, doing this periodically. Edited October 16, 2009 by Kai_Wolf Quote Link to post Share on other sites
Raven1 Posted October 16, 2009 Report Share Posted October 16, 2009 Gun shot like a champ last night, put another 18 magazines through the gun and zero issues. The updated springs in the magazines actuated the bolt stop every time, worked so cleanly that t_hum had to double check a few times to verify the bolt locked back. He was so focussed on maintaining his 1 second cadence he didn't know the bolt locked back. It was funny actually. Rapid fire full auto testing and single fire as fast as you can shoot testing didn't cause the magazine temps to drop and all in all were consistent. In all of this I need to mention the stock hop up and inner barrel are getting the job done nicely. Accurate and repeatable, even with over 6000 total rounds through the gun, which incorporates testing, extreme testing conditions and 2 full days of skirmishing. This gun keeps going and going and takes abuse like Sasha Grey on Ecstasy! Quote Link to post Share on other sites
gunnermaniac Posted October 16, 2009 Report Share Posted October 16, 2009 (edited) Just so people know, I would have liked CO2 not only so I can use it in the cold winter months here in England with little fluctuation of performance but also because I do not like 134a or green gas in general. It costs a fair bit and is messy (hard to explain what I mean by this but CO2 is a nice neat capsule, pop in and pop out) I don't like gassing up mags either. It's just a personal preference. Do you guys think a mod would be possible as on the WE, where you could lower the fps if using CO2? Edited October 16, 2009 by gunnermaniac Quote Link to post Share on other sites
elrey Posted October 16, 2009 Report Share Posted October 16, 2009 The updated springs in the magazines actuated the bolt stop every time, worked so cleanly that t_hum had to double check a few times to verify the bolt locked back. Was the bolt stop not working correctly with the stock springs? Quote Link to post Share on other sites
t_hum Posted October 17, 2009 Report Share Posted October 17, 2009 (edited) That sounds Awesome T hum, I cant wait to get one from you. Also, I had a question. My full auto studders irregularly sometimes and I think it is beacuse my cup seal has tears here and there in it. Does that make sense or would that come from another part? Will the O ring Piston help with keeping the shots regular? My Cup seal is jagged on the edges and I think it is the cause as when I first shot the weapon on auto, it was very regular, but now if the trigger is held down, it studders for a few moments, and then goes to a regular pattern again, doing this periodically. Could be possible, I guess. Depends on how rough the edges are. Perhaps the seal is now too small in diamter and had the ability to fold backwards and therefore gets caught. Can you post up a pic? Shots seemed really consistent last night. Should eliminate any variables in seal found the cup seal if there are any to speak of. Edited October 17, 2009 by t_hum Quote Link to post Share on other sites
psychofox Posted October 17, 2009 Report Share Posted October 17, 2009 I had my kj m4 serviced by kjw for a small crack on upper receiver. and fractured part #15. KJW replaced both the damaged parts and also installed a new style piston. The piston fells lighter though it is not as prettycompared to the orignal black version. Quote Link to post Share on other sites
wdahm519 Posted October 17, 2009 Report Share Posted October 17, 2009 (edited) The new style piston is direct from KJ Works as well? I'm a bit confused. T_Hums, do you work directly with KJW? Edited October 17, 2009 by wdahm519 Quote Link to post Share on other sites
t_hum Posted October 17, 2009 Report Share Posted October 17, 2009 (edited) The new style piston is direct from KJ Works as well? I'm a bit confused. T_Hums, do you work directly with KJW? Ha, no I don't. I think what he showing us is that KJW made some sort of revision to their original design. I can see from the photo that this one locks into the plus shaped front on the bolt carrier and has a different profile. My gut instinct here tells me the changes came as a result of trouble installing the pistons quickly on the assembly line OR they didn't have the mold done in time for the release and made the simpler round parts in the meantime or a combo of both. I mean, the carriers have had the plus shaped cuts in them all along and knowing TK he didn't put them in for fun. His designs are smart and those cuts are purposeful. Still uses a cup seal which is the main culprit in a damaged part #15 and potential efficiency issues. To be totally clear, this new design isn't anything like mine. Edited October 17, 2009 by t_hum Quote Link to post Share on other sites
MrTreble Posted October 17, 2009 Report Share Posted October 17, 2009 psychofox - That piston looks like it was sanded down or something. How does it shoot? Any problems? Did your M4 come with a serial number? Quote Link to post Share on other sites
psychofox Posted October 17, 2009 Report Share Posted October 17, 2009 MrTreble - Mine was serial numbered. It looks and feels like it was sanded down. The performance is about the same and no problems yet. Quote Link to post Share on other sites
Raven1 Posted October 17, 2009 Report Share Posted October 17, 2009 Was the bolt stop not working correctly with the stock springs? elrey, The 'Original' production run of guns are 'Serialized' on the reaction side of the lower receiver from KJ00001 to KJ00250 and did Not have the updated Buffer, Buffer Spring and Magazine Spring equipped on the gun. If a gun was purchased that had the serial # on the gun then a quick email to KJW with a picture of you serial # on the gun would have gotten you the correct updated parts. Gun With NO Serial Numbers Are Already Updated and Good To Go! I must also state that my rifle is also equipped with the Magpul B.A.D. and has no effect on the gun what so ever! Well,,,if you call super fast mag reloads no effect then there you have it. In any case the bolt locks back Every Time. Very satisfying to know that when you run the gun, shoot and move with the gun either upright, from the side (as in laying on your right or left side from an improvised urban position) or Fully Inverted (yes kids I mean UpSide Down) the gun still shoots well and locks the bolt back. However it should be noted shooting inverted induces more gas consumption. But if your ever roping down and you get hung up there is nothing like going to direct action mode and the gun keeps running regardless of what orientation you are in when driving the gun. Instilling doubt or even fear in Non Waffle Hardware, simply put "Fear Da Waffle!" Having said that,,,,"WAR Waffle!!" Quote Link to post Share on other sites
Apache137 Posted October 17, 2009 Report Share Posted October 17, 2009 This gun keeps going and going and takes abuse like Sasha Grey on Ecstasy! Sadly, i understood that reference lol anyways, back to more important, slightly less entertaining things.... did you only try the piston or did you try the velocity reducer/adjuster? or is that still in fab mode? I cant wait to pick this up... my tax return is late coming, but should be a good few hundred bucks.... i think my tax return my come in the form of Koba San and Kuan Ju's achievements If these are as rock and roll solid as everyones making them out to be, I might be able to swing my whole team into going GBB m4, which would be awesome. They're less than impressed by the maintenance that goes into my WOC.... and the price lol now all we need is some trademarked bodies and we're good to go. I cant believe no ones cranking em out yet. KJW seriously needs to take 20 pieces, w/ 3 mags each, and ship them to all of the major parts manufacturers like prime and GP, and ebay banned, so they can pass em on to their "super secret" china manufacturers who are cranking out those budget WA bodies.... So they can see the incredible potential in these and make some effing parts already! I know they're trickling out, but still, no trademark bodies makes me a sad panda. Also, Raven1, how much did the BAD run ya, and was there any modification required to install it? Keep up the good work T_hum Quote Link to post Share on other sites
t_hum Posted October 17, 2009 Report Share Posted October 17, 2009 did you only try the piston or did you try the velocity reducer/adjuster? or is that still in fab mode? The prototype is made but we didn't get around to testing it due to not having a chrono on hand. Testing is on Wendesday evening so expect reports on Thursday. Quote Link to post Share on other sites
Apache137 Posted October 17, 2009 Report Share Posted October 17, 2009 awesome, thanks... do you care to elaborate at all on how you made it? or what part of the gun it affects? thanks. Quote Link to post Share on other sites
t_hum Posted October 17, 2009 Report Share Posted October 17, 2009 (edited) Its a replacement for the current negative pressure valve. The part is pretty much the same but with different sized ports and different ID. Its taken some work to figure out how and where to place holes in the piece to maintain decent flow and get around some of the design features not available to me as I dont have an injection machine. And, instead of ABS plastic my nozzles are Delrin copolymer for better lubricity and toughness. Raven1's stock valve blew up under 115 degree propane use which is, of course, excessive. The Delrin is tougher and less brittle while still maintaining excellent dimensional stability during machining. Edited October 17, 2009 by t_hum Quote Link to post Share on other sites
wdahm519 Posted October 17, 2009 Report Share Posted October 17, 2009 I don't think anyone has actually addressed this in the 37 pages of this thread, but: Does the KJ M4's charging handle take aftermarket latches (aka, is it "real spec")? Or does it have its own spec of pin and latch? Quote Link to post Share on other sites
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