SSPKali

Think I have the MWS just so now. MWS Hao 10.5 UGRI rail Ambi charging handle Magpul stock Hogue grip 60deg fire selector (low profile on left, higher profile on right for manipulation shooting left handed) Magpul Mlok sling mount BCM rail covers Magpul foregrip and hand stop Olight Odin mini no name mini suppressor inside hand guard Vortex red dot and clone Unity riser Ferro Slingster

I think the issue here is the bolt is obviously out of spec (or not designed to work with the regular TM receiver…which sounds like a get-out clause!) I would look where the bolt is catching and file off the bolt part, no point trying to alter the receiver or spend ££££ on an aftermarket one only to find out the same thing happens! Worth cleaning out all the chips and dust, won’t do any favours if that gets in the workings

MWS mags without the “mod” will fire 120 rounds easy. That is normally a 12-14g fill of gas, easy to work out vs the weight of gas in the can. One can will be plenty for a days play, maybe take two if you are worried. Cutting the silver tube down to cram more liquid propane in is a DUMB idea. Pushing o-rings into the fill valve to prevent the “gas leaking out when filling” is a DUMB idea. The Marui engineers are not dumb.

I tend to wear my usual every day watch, not had it shot out yet but figure I would have to be really unlucky to have it damaged by a bit of plastic. Elliot Brown Holton or Steinhart Vintage MilSub depending what I fancy on that day.

Thanks for the extensive advice! pre-cocking and AB are off and it rarely does it, turning on pre-cocking increases the occurrence. Not tried PC and AB together…I was under the impression that the AB++ couldn’t have both “on” at once (even if the LEDs said they were both enabled, only one was working?) Having run it without the upper receiver on I can see the piston sitting further back each shot until at some points it double shoots. Just given it another test and it was good as gold! Bloody typical! Will still throw an old motor in just to see. Might try a new cut off lever and / or trigger contacts if that fails. It might be down to the cut off nub on the spur gear being a hair different and messing things up. UPDATE: Just tried with PC on 1 / AB on 2 to 3. Still double tapping. No PC and AB on 1 and no double tapping… but the occasional failure to cycle (sad whiring noise!) Just fired 150 times with everything OFF and it didn’t skip a beat! I love transient issues! Thanks for all the suggestions, will keep in mind if it starts playing up again.

Thanks all, I am running a 300mm x 6.01mm barrel and 0.28g BBs. Cut off lever is working fine and being tripped by the sector gear. I am starting to think I will sell the Warhead motor and fit an XT or SHS one as this is only a back up gun and spends more time being used as a test bench than actual use 😁

I have recently fitted some 13:1 Solink helical gears to my M733 build. Everything else stayed the same - warhead motor (mid speed one?) 7.4v via a Perun AB++ Totally flawless with the SHS 13:1 gears but a bit noisy, hence the helicals. Now it has started double tapping every 20-40 shots. Tried turning off precocking, turning on “sniper delay” or using AB to no avail. Stripped it down the check trigger trolly and cut off lever - apart from a little greasy gunk I dug out all working fine and shimming spot on. Took one tooth off the pick up side to drop power a smidge (right on site limits with an M95!) and it is still doing it. Any ideas?

Ok, did some more testing and checked the fill and exit valves. The fill valve is directly threaded into the back face of the magazine and there is no syphon tube so it is easy to completely fill the gas chamber with liquid propane (or near enough!) Meaning there is little gas available for firing a BB, and shots in quick succession lead to a drop in power due to it taking longer to replenish the gas pressure by boiling off the liquid propane. 8-10sec fill seems optimal. The exit valves on one of the mags was a little sticky so I removed it, lubed with very light silicone oil, wiped the excess off, and refitted. Much more consistent FPS and even gained 5FPS due to efficiency. I did the other mag and found it didn’t make much difference, but that one was always working better any way. Hope this helps anyone else who gets the G&P MWS mags and finds some less than great performance.

Anyone else tried the G&P L Mags (46rd ones)? Seem to be getting some very hot shots for 1-2 BBs then settles down. 285, 276, 263, 260, 258…. My TM STANAG mags give 266fps +/- 2fps. Leaving the mag for a couple of mins and trying again gives shots around 266 which is what I was expecting. I am wondering if a 15sec fill is too much and not leaving enough gas to liquid volume. They don’t have the TM style fill valves that vent the air, so I guess they also lack a fill syphon to prevent over filling? Extra rounds and snappy recoil is welcome I just want a more consistent performance.

It probably won’t wear the nozzle guide much as it will naturally roll the hop wheel and not scrape across it. A non-destructive way of testing would be to put a long strip of gaffer tape in the channel in the upper receiver that the charging handle runs in. That will move the bolt down a hair and may stop the issue. Then at least you know the likely cause and can always peel the tape out after testing.

I think the “gas key” is the nub at the top of that part that fits in the underside of the charging handles. Obviously there are slight differences between the firearm and airsoft M4 designs so not a direct comparison 👍

Hao put the sticker on the upper left face of the BCG (opposite side to the ejection port) it probably needs less than 1mm removing, best to take a little off and try rather than going mad with the angle grinder! I have experienced it with certain combinations of nozzle guides and charging handles. The old worn TM guide and handle was bad for it. Once replaced and the sharp edge taken off the cut out I have had zero issues

The part circled in red is the cut out for the hop up wheel. To make more room you can either carefully file out some more or make the bolt carrier and nozzle guide run “lower” in the upper receiver. Hao achieves this with their BCG stickers for example.