Advice on these upgrades needed

[maporms]

Originally Posted by m102404

I meant the snide remark is a good way...LOL.

Upgrading your AEG (and kudos to you for figuring it out and doing your own!) can be both rewarding and massively frustrating at the same time. There are some general guidelines for good setups...but most times you just have to try it out and see what you get.

Because of the slight variances with all the parts and the number of things that can affect the end result (be it FPS, accuracy or ROF) it's near impossible to say..."add part X and you'll get result Y".

Obviously some rifles are easier than others to work on...unfortunately, with a TM MP5, you've got to take out a good number of screws and split it in half to get to the goods. And just when you think you've got it...you strip screw hole threads, or drop one stupid little o-ring and can't find it, or slip with the screwdriver because you're rushing it and scratch the finish, or any other bone head thing.

The worst part (if you're obsessive compulsive like me) is when you have your rifle setup perfectly...and then tear it all apart again just to fiddle with something else for the hell of it! LOL.

Then you end up with enough spare parts to almost make another one...and it starts all over...

Last week I bought a SAW...70% of the reason I bought it was for the quick change spring feature. I've got about 30 misc springs that I want to chronograph and I don't want to have to disassemble my M4 just to try each one of them out!

Same reason why I go for AEG's with Version 3 gearboxes. Much easier to maintain.

[grimreefer]

Sold a spare AEG this morning which allowed me to purchase my mechbox upgrades. Here's what's going into my MP5 as soon as they arrive:

1 ea. G&P AEG Grease Set
1 ea. Modify Enhanced Tappet - V2
1 ea. Modify Air Seal Nozzle - MP5 Series
1 ea. Modify Enhanced Cylinder Head - V2
1 ea. Modify Enhanced Cylinder (300mm-450mm)
1 ea. Modify Polycarbonate Bearing Piston Head
1 ea. Modify S110 AEG Upgrade Spring
1 ea. Sorbo Pad for V2/V3 Cylinder Head

in addition to the parts I already had ordered:

1 ea. Mad Bull 6.03mm Tightbore Barrel - 363mm
1 ea. Mad Bull Quicksilver Black Oxide Silencer
1 ea. Guarder Improved Hop-up Set - Black

The tappet is a backup. I am likely going to wait on installing the 110 spring until I chrono with the compression upgrades. Right now my ROF is 760 RPM, and the real-steel is 800 RPM so I don't want to loose ROF if I don't have to.

[GreyFox132]

why not try the mad bull shark hop up bucking. stops double feeding and increases fps

[grimreefer]

I accidentally chose the wrong shipping method for my barrel and hopup. They haven't arrived yet. But yesterday I installed my new cylinder, piston head, cylinder head, sorbo pad, and nozzle. I re-greased and re-shimmed the gearbox perfectly. I think I even ended up with a better ROF. Here's the weird thing though....my velocity decreased. I tested the compression with the new parts, and it was awesome. Better than what I took out.

So how the hell could I end up with decreased velocity? I can't figure it out. Tested in semi-auto...

[The Saint]

How much did it decrease by?

And stay away from the Madbull hopup sleeve. Never heard a good review.

[Skladfin]

dont get the air seal nozzle with prom air seal hop rubber.

you will have jamming problems like there's no tomorrow

[grimreefer]

Originally Posted by The Saint

How much did it decrease by?

And stay away from the Madbull hopup sleeve. Never heard a good review.

I can't say for sure as I haven't chrono'd. All I know is that it was penetrating a piece of insulation foam before, and now it's not.

[Skladfin]

did you change the hop up rubber yet?

maybe you installed the spring backwards

maybe you installed the cylinder backwards

[grimreefer]

Originally Posted by Skladfin

did you change the hop up rubber yet?

maybe you installed the spring backwards

maybe you installed the cylinder backwards

I installed the spring with the more compressed end to the rear, and the cylinder with the port to the rear.

Doesn't seem to be a major decrease in velocity. If I wasn't using the insulation foam as a target I don't think I would have noticed. I was really hoping for a performance increase though....

[Syn]

Check the nozzle you installed with the stock nozzle to see if the modify one is shorter. If it is shorter then it won't completely seal with the hop up rubber giving a good "kiss" to seal, decreasing your FPS.

[grimreefer]

Originally Posted by Syn

Check the nozzle you installed with the stock nozzle to see if the modify one is shorter. If it is shorter then it won't completely seal with the hop up rubber giving a good "kiss" to seal, decreasing your FPS.

I think this is the problem...but the air-seal nozzle is the same size as the one it replaced.?? I ended up re-installing the stock nozzle. I've replaced the hop rubber, and have made sure the mech box and all parts are seated properly. With the nozzle completely forward, I can see that it's nearly 1mm away from the lip of the rubber. I was thinking of buying a longer nozzle designed for another gun and sanding it down?

[Syn]

Is your hop up chamber metal or plastic?
Because if it is metal, you could shave the 1mm from the tabs and that would bring back the hop up chamber back closer to the mechbox and hence give you a good nozzle seal. I did this with a metal chamber.


shaving from the plastic hop up chamber tabs could be risky and result in broken tab and you buying an whole new chamber.

I was tempted to take my nozzle to a seller to try to match it with a slightly longer nozzle but I would have to bring the cylinder head too in case the nozzle inner diameter is different. Anyhow that was to much work for me.


oh and make sure the anti reversal latch is fully off the gear (and pull the nozzle forward by hand) when testing distance of the gap. The nozzle has to be fully forward or it will trick you into thinking the gap is huge.

[grimreefer]

Originally Posted by Syn

Is your hop up chamber metal or plastic?
Because if it is metal, you could shave the 1mm from the tabs and that would bring back the hop up chamber back closer to the mechbox and hence give you a good nozzle seal. I did this with a metal chamber.


shaving from the plastic hop up chamber tabs could be risky and result in broken tab and you buying an whole new chamber.

I was tempted to take my nozzle to a seller to try to match it with a slightly longer nozzle but I would have to bring the cylinder head too in case the nozzle inner diameter is different. Anyhow that was to much work for me.


oh and make sure the anti reversal latch is fully off the gear (and pull the nozzle forward by hand) when testing distance of the gap. The nozzle has to be fully forward or it will trick you into thinking the gap is huge.

the hop up unit is plastic, but there's not enough material to remove to bring it any closer. I can't think of any way to mod it.

I actually took the mech box apart and made sure the tappet was all the way forward. I put it all back together very carefully making everything fit as best as possible. Then I flipped the gun over, shined a flashlight down the barrel, and looked through the mag well into the hop up unit. It's a significant gap (almost 1 mm) and it certainly isn't sealing.

[Syn]

Well then for significant gap of over afew mm, get a longer nozzle would be my best suggestion rather than filing a mm off the tabs.

One guy filed the tabs off completely to make sure the hopup chamber sat flush against the mecbox. I think he may had too much problems with it then got fed up and filed off the tabs. He might have even filed the chamber slightly IIRC. My concern is keeping the chamber from rotating in that extreme "solution".

I'm surprised the fit is bad on a TM. Might have expected that on a china clone. You absolutely sure the gap was there before with your old nozzle, and is the gun is assembled correctly. Was it firing poorly before too? I wonder if replacing another part would get rid of the gap. Might consider getting a second set of eyes like a gun doc to have a look at it.

[grimreefer]

it's possible that the gap is in the hop-up unit. between the retaining clip and the actual hop-up unit. i'll take it apart again and see if I can get things a little more snug. there was a gap in the stock hop up assembly and I thought the barrel was as far into the hop-up as it could go....but i will try again.