Lemme run this by ya....

[Jbone 11 11]

I've come into the possession of a couple M4's, a Cybergun Full Metal "Colt" M4 RIS and a G&G GR16 Carbine light.

I got a few dollars to throw into the mix, but essentially I'm aiming to combine the best of both worlds to make one as good as it can be and the other a basic back up.
I figure if I pop the G&G gearbox into the metal body of the Cybergun, I basically have TR16 ....well, sort of.

Throw a tight bore and some new rubber and a mosfet (I like running 11.1v Lipos) and I should for all intents and purposes have something fairly decent.

What I am wondering though is this: Is the G&G gearbox actually any better than whats inside the Cybergun and are there some other less expensive mods to consider that I could throw into the mix?

[lurkingknight]

these are the things I am most queasy about changing out of perfectly working guns/gearboxes.

in any given gun that's working:

changing out the gearbox shell.

changing out the hop up unit.

changing out the nozzle.

changing out the trigger mechanisms, electrical or mechanical.


I have observed strange things that can happen when changing out gearboxes, from unexplained loss of fps to not fitting in guns. Avoid changing a shell unless absolutely necessary. A properly prepared v2 shell unless plastic can be made to last reliably.

Mixing and matching hopup units to gearbox shells can result in difficult to troubleshoot airseal issues. This sort of coincides with the next one of nozzles. a fraction of a mm can throw off your air seal and cause you to pull hair out. Generally though v2s are fairly well sorted and the nozzle lengths aren't drastically different from brand to brand. Having a set of calipers to measure the old nozzle vs the new one will tell you if you may or may not encounter issues.

I had an SRC 416 with a G&P gearbox in it with SRC trigger parts that would not shoot. It took me 10 hours to try everything and eventually led me to rewire the original g&p trigger bits back into the gun and without changing anything else, it started working again. That little bit of an 'ergonomic' change from the owner caused himself some number of weekends and me 10 hours to discover and fix.

That cybergun is probably a king arms, which if it is, has a reasonable gearbox shell. Look at fixing the components within the gun rather than starting to mix and match 2 brands. A few bucks in air seal components will go a long way to making either one or both guns shoot really well. Consistency in fps trumps all other mods you can do, including barrels and hopups.


without opening the gearboxes and verifying what's in them, you can assume both have average to no shimming, plastic toothed piston, no bearing on the piston, no vented piston head, dry as a bone o-ring, no bearing on the spring guide, standard gears that may or may not last. If you're lucky an O-ring nozzle and standard 18g wiring.

If you have no idea how to do any of that, you know where to find me. :P

[Jbone 11 11]

Thanks for the advice....some good detail in there. But one thing puzzles me on moding given what your saying and that is, if a gearbox can be made to be reliable no matter the make, then what is the difference (external parts not included) between the top brands and cheaper brands? Outside of the differences in the gearboxes, this leaves relatively minor stuff like the hop up and barrel swaps.

Granted, I may be oversimplifying things, but if thats the case, then why would anyone waste money on a top end brand?

[Stealth]

QA.
Exactness of tolerances.
Adherence to industry specifications
Compatibility between wider number of brands

These are all paramount when the difference between a great gun and a shitty gun is measured by literally fractions of a millimetre.

[Rusty Lugnuts]

personally i buy higher end brands to try and avoid the weird, hard to diagnose gremlins that are more common in cheaper guns.

[Jbone 11 11]

So...if I have this right, its really all about the relationship between the piston, nozzle and HopUp etc...in order to get as much air as possible pushing the round down range.

Then after that its all about the mechanical/electrical. But the differences between brands, all things being equal (i.e. if the cheaper stuff works as advertised) the differences are negligible at best.

I mean from the little I know, the only advantage to better Mech and electrical is less heat over time....which translates to less wear and tear.
And I figure this really comes into its own for those that game a lot or are running a support weapon where consistently high ROF is needed. So for your average to moderate player, this type of mod seems a waste until its needed, i.e. the Mech or Electrical goes down.

Is that about right?

[Rusty Lugnuts]

Nope Too much air is bad ,Too little air is bad and Inconsistent amounts of air makes your gun inaccurate. Consistency is achieved with quality parts. Plus would you drive a Lada if a Mercedes was only a couple Hundred bucks more?

[ThunderCactus]

They dont charge money for nothing
And its important to start with a good base.
You can upgrade a ford festiva and a ferrari to both have 600hp, but come race day its obvious what you'd rather be driving
Theres plenty of upgrade threads that explain the details around here

[Krawch]

Originally Posted by ThunderCactus

They dont charge money for nothing
And its important to start with a good base.
You can upgrade a ford festiva and a ferrari to both have 600hp, but come race day its obvious what you'd rather be driving
Theres plenty of upgrade threads that explain the details around here

Thats genius best saying I have ever heard on asc haha that is signature worthy

[lurkingknight]

some combinations are more forgiving than others... you rarely run into an issue with the nozzle being too short or long... there's a good reason pull out the calipers and measure every nozzle I can get my hands on.

Even buckings can be off spec and cause seal issues or overhopping... hop up chambers can do the same too by pushing the nub too far into the window.





Most of the time it's not a huge issue... but when it shows up as a problem, it can be a very time consuming venture to find out what's causing it. If you're new to working on guns, it's a good practice to only change one thing at a time to observe results each time something is changed... cause if you just throw all the parts in, you're going to have to start mixing and matching to figure out which one causes the issue... and it may not just be 1 part doing it... it might be a combination of parts.


It's not the price you pay for the parts either, it's how the parts interact with each other. You can take a 30$ systema nozzle and put it on a 5$ acm cylinder head and if it seals, you're in business. But you can also take a 5$ nozzle and put it on a 5$ cylinder head and it will seal just as well. It's a matter of finding the proper combination of parts. I have a modify p90 nozzle on a modify p90 cylinder head that leaks worse than if it had no o-ring... in fact... I had 2 nozzles and 2 cylinder heads just to make sure they sucked. Now I don't buy modify parts. That's just an example but there's a reason I have a preferred hardware list when clients come to me with gun issues. I know the parts that work for me, and spending an extra few bucks on my preferred list will have known and desired effects.

Originally Posted by Krawch

Thats genius best saying I have ever heard on asc haha that is signature worthy

Yes, but odds favor the guy who souped up the fiesta of not being a pretentious self righteous, cunt. :P

[Jbone 11 11]

Originally Posted by Krawch

Thats genius best saying I have ever heard on asc haha that is signature worthy

Err...not really...thats a pretty subjective comparison. If you gave me a Fiesta with 600hp(WRC?.....Ken Block anyone?) on a WRC or rally cross circuit, great.... a ferrari on the same circuit....not so much. LOL!

[Jbone 11 11]

Originally Posted by Rusty Lugnuts

Nope Too much air is bad ,Too little air is bad and Inconsistent amounts of air makes your gun inaccurate. Consistency is achieved with quality parts. Plus would you drive a Lada if a Mercedes was only a couple Hundred bucks more?

Ah...I see...makes sense, sort of. Why is too much air bad? I mean yes, if you stuck a nozzle from an air compressor and blew 300psi into the gun, for sure the thing wouldn't be able to handle it. But given the tolerances were talking about I would have assumed that the more air you got pushing the better and you'd get more air by having a more efficient delivery. Efficiency and air delivery go hand in hand no?

Is it not the same principle with tightbore barrels? Keeping the most air behind the bb without restricting it by being too tight?
I might not be explaining my thoughts properly though....

As for the Car references....you guys should do your homework....Lada's can be just as reliable if not more so than a Merc. Ask any Lada mechanic....I know of 5. Specially these days. Merc's suffer from...wait for it....poor quality control. Lada's.....well, the only problem with them were dudes would pinch pieces off of them during the shipping process to the point where you'd be missing half the engine by the time it got to you LOL! Left in one piece they were actually well built for the money....

Gotta come with better examples guys ;P

[m102404]

When it all comes down to it...you really only want two things:
1. A consistent backspin on a BB

2. For it not to break down

1. Consistency
Consistency = Accuracy and for AS stuff that means pushing the same amount of air at the same rate...and the same amount of backspin being applied to every BB.

To get the same amount of air at the same rate the compression components need to be sealing up nicely. Respectively in each build...a factory cheapo o-ring on not-fancy piston that seals perfectly will accomplish the same consistency as a uber-l33t polyurethane nuclear resistant o-ring on a speed hole lightened piston made out of unobtanium.

Compression seal parts are:
- piston head oring to cylinder
- cylinder to cylinder head
- cylinder head tube to nozzle
- nozzle to hopup rubber
- hopup rubber to inner barrel

Get them all sealing and performing consistently shot to shot...and your build is as consistent as any other consistent setup. Even on a setup that leaks a bit between any of the parts can be consistently accurate...as long as it's leaking consistently shot to shot.

It can be done on a sub-$250 CYMA...and on a $1000+ PTW. Maybe easier and less headaches on the one with parts made to closer tolerances....

Application of backspin
Assuming that the amount and rate of air propelling the BB is the same, how the backspin is applied comes down to the surface of the BB, the consistency of the BB diameter and the material/nature of the hopup rubber. It's the "simplest" part....but it's where the real magic happens. Good hopup application = shots flat and true as far as you can see them disappear in the distance. IMO...you don't necessarily need a hopup system that can spin a 0.9g BB straight up like a ballistic missle...just one that put just the right amount of spin on your BB weight for your setup.

2. Not breaking down
So all the above can be done with both shitty parts and great parts...but for how long can it remain repeatable? There's really no definitive answer that fits every scenario. I've always said that it's not if your gun will break down, it's a matter of when and what goes first. In the end...you're basically just hedging bets. Buy good motors...they should last longer than cheapo motors. Use good pistons...they should last longer than crappy pistons. Use good gears...they should last longer etc, etc, etc....

A couple of good rules of thumb:
- don't fix what ain't broke
- change one thing at a time, test and observe, repeat as desired
- avoid mixing and matching parts that directly touch each other (i.e. Modify will produce all their parts spec'd to their spec's...Lonex builds their parts to their specs...etc....but it's doubtful that Modify/Lonex/Guarder/SystemA/etc... all use common specs)

IMO...there's a sweet spot for accurate BB flight. And it depends on BB weight but in general using BB's in the 0.25-0.28-0.30g range and sending them out somewhere in the 360-380-390 range. Take a setup that is shooting really well with 0.25's @ 360 and then swap just the spring to result in 380fps and you may find that it doesn't shoot as well. It might take a different hopup rubber to settle things in or maybe a heavier BB weight...but it's a bit of a crap shoot. Over and over the sweet spot for some of my guns was 399fps w/0.28's and 385fps w/0.30's (actually...shooting those velocities with 0.20's but using the respective BB weights in the field)... Different guns, different hopup rubbers, different springs. Pretty similar ballistic results though.

PS. Taking the piston oring off to drop FPS is nuts. It'll work...but what a weird way to go about it.

[Jbone 11 11]

Hey...great info there m102404, well said.

[lurkingknight]

too much air isn't necessarily bad.. it creates certain effects that you may or may not want.

A couple being more noise at the barrel end.. it will pop louder and something called joule creep. That's something that's been explained thoroughly elsewhere. To paraphrase it.. there will be more energy to move heavier rounds, so you can raise muzzle energy using heavier rounds while keeping muzzle energy on lighter rounds lower.