First Build - MP5 DMR, Needing Opinions.

[DSCAllDay]

I'm going to start off with a big thank you to Minerva who helped build this list, planetarian for help explaining electrical stuff both in this thread and in PM, Blake for his all around knowledge, wetsuitxninja (Ben from No Limit Airsoft and Paintball) for getting me a good deal on some parts, EDI1st and unlimitedRA1N for his guidance in the early portions of this build and others on ASC, ASF, and ASM to help nitpick, give me my list, and help edit the list a tad.

 

I am looking for the best possible parts on a high end budget. If you could help me out with the questions I have and give me advice on which parts to use, I would greatly appreciate it.

 

This will by my thread for my MP5 DMR Build, I will be documenting the build from start to end. I may need to modify RS parts to fit on this gun and I think it would be helpful for me to post this here.

 

Base Gun:

G&G/Umarex MP5A4

 

Internals

 

Lonex A2 Infinite Torque Motor: 55

Lonex D Air Nozzle: 7

Lonex 1/4 Port Upgraded Cylinder: 14

Lonex POM Piston Head w/o Bearings: 14

Lonex Double O-Ring Cylinder Head: 13

Lonex Extreme Toughness Piston:

RiotSC 10:44 Revolution + Gears: 120

Modify Ceramic Ball Bearings 8mm: 30

Modify Torus Reinforced Gearbox Shell: 65

ARS Hayabusa Thrust Bearing Spring Guide: 20

Prometheus MS135 Non-Linear Spring: 20

Prometheus 6.03 363mm EG Barrel: 60

Prometheus Soft Hop-Up Bucking: 18

HunterSeekerArmory Barrel Lockdown Kit: 10

HunterSeekerArmory 2-ER Hops: 17

HunterSeekerArmory 2-EM Nubs: 14

Extreme-Fire: Cheetah 2N! Mosfet: 100

 

14 AWG PTFE Wiring

Deans Ultra Connectors

Custom 14.8v 35c LiPo Battery

 

Mods (Done by experienced Tech):

70d Sorbo

Correct AoE

Shim Job

Polishing

Radiusing

 

Externals

 

Real Steel Fleming's Firearms HK to AR Adapter: 115

Real Steel Magpul PRS:

Real Steel DMPS A2 Buffer Tube: 15

Real Steel Troy MP5 BattleRail:

Real Steel VLTOR Mod Pod

Real Steel Accushot Adjustable Precision Monopod

Real Steel Trijicon ACOG TA31A

Real Steel LaRue Tactical 1 O'Clock Offset Mount

Real Steel Aimpoint T-1

Real Steel Troy Aluminum Modular Foregrip

Real Steel Gear Sector Aluminum Handstop

 

Thanks!

--

 

My first question:

I have an update for everybody. I will be putting in a M170 and buying a Lonex Red Piston, which then will be SS'd down to a M135~M140. So I had a couple questions.

Whats the difference between the short-stroked M170 or the full stroked M135? It seems intuitively that the motor would work harder, but there is no science behind my opinion. Second, will this increase the Rof? By how much? And third, would my setup handle it?

[Avenger96]

Well, since you asked for opinions, mine is that you should do it with an SVD or G3 or something that isn't an MP5.

 

Just my .02

[Bando]

gotta agree with avenger but it is your project so go for it

[DSCAllDay]

Haha. I get that and have gotten that many times. I'm trying to create a unique build though. I also am a huge MP5 fan, i just like the look of it tbh.

[renegadecow]

Drop the "DMR" and people will get less confused. One is from the fact that it's built on a 9mm sub gun and two, the parts list assembled in my minds eye is no longer than an M4 with a 14 inch barrel.

Other than that, drop the ball bearing bushings if you're gonna make it pull an M170. They're more for high speed and can get damaged on a high fps spring with prolonged use. Also you've got plenty enough power from the torque motor and torque gears to pull an M170 easy. What raises an eyebrow is that 14V 35C battery. If you want a high fps, high rof build you may just make better savings by investing in a Polar Star gearbox.

[DSCAllDay]

Drop the "DMR" and people will get less confused. One is from the fact that it's built on a 9mm sub gun and two, the parts list assembled in my minds eye is no longer than an M4 with a 14 inch barrel.

Other than that, drop the ball bearing bushings if you're gonna make it pull an M170. They're more for high speed and can get damaged on a high fps spring with prolonged use. Also you've got plenty enough power from the torque motor and torque gears to pull an M170 easy. What raises an eyebrow is that 14V 35C battery. If you want a high fps, high rof build you may just make better savings by investing in a Polar Star gearbox.

 

Sure, but I will be using it semi auto sometimes. It is a field/DMR build. Longer barrel does not necessarily equate to better accuracy. I still want this to be a easily handleable gun, and a 450mm+ barrel won't do me no good. I think I could hit 300' accurately with this. I have asked all around, and the general consensus was that the ceramic ball bearing were the best out there. They have a lower friction coefficient, and a harder surface. If I was using steel bearing bushings I would agree with you. And I'm using 10.44:1 Riots. these are NOT high torque gears... I'm using a M170 SS'd to a 140ish. I hate P*'s.... I just get turned off by the tank etc etc. As you can see I'm all about indivuality and being unique with performance. You cant really customize internals with a P*. Besides the nozzle ofc. thanks for your input though. It would have been more helpful if you read the OP.

 

Oh and I'm prolly using a custom 13.3v. Depends on if my motor dies or if my mags can't feed that fast.

[Avenger96]

I wouldn't argue with RC if I were you...

[DSCAllDay]

I wouldn't argue with RC if I were you...

 

I'm not trying to argue...

 

If it came out that way, my bad.

[Bachelarius]

Interesting parts list. Your piston will almost certainly need to be lightened either way, but the difference between the m170 SS-ed is that it will return faster, thus ENABLE a faster rof. It will not raise or lower your ROF either way.

 

Questionable parts are definitely the bearings, I agree - you just don't need them. You will be putting a lot of stress on them. I advise TerminusX Bushings instead, if you can find them.

Also, the hop rubber. If you are using HS5's hop parts, the aim of the rubber is to seal and prevent blow-by. For that you need a hard rubber, any reason why you decided to go for the soft?

 

I personally don't remember what the MP5 hop is like and have never worked on a G&G one before, so don't know the answer to this, but does the hop unit have enough room and adjustability to even accept an ER-hop? Or are you going for a fixed hop approach? If it does not, you may need some snibbles and may find that there is no way to fit the EM-Nub at all.

Also, what lubricants do you plan to use?

Will the 14awg wire fit inside that Taurus? PTFE is a good choice though.

Also, how do you plan to maintain this build? How and how often will you lube the piston o-ring for instance?

 

This is a pretty heavy build, I mean, it'll require a lot of custom tweaks, polishing and dremel work to even work for a short while. I'd consider building it and starting with a 7.4 and working your way up to 11.1v, checking for Pre-Engagement and wear and carrying on like that, or using ROF limiter in the Cheetah to slowly test your build.

 

And I have not even touched on anything other than the internals, you externals will have to be solid as a rock as well.

 

Good luck though, I have no idea of your experience in AEG work, however a build like this will require it, otherwise it will prove VERY costly. And asking all the questions in the world will not help you when you come to assemble your gearbox and find that one part or another does not fit or your switch assembly is not tripping correctly or your tappet is not returning fast enough. To jump straight into a build like this is ridiculous :/

[renegadecow]

10.44:1

Misread that one. Actually, I didn't even know that low a ratio existed. I normally don't see anything lower than 14:1 when pulling an M140 and higher.

[Yuri]

I don't really understand why you'd use a high speed gear set to pull a very heavy spring and then short stroke it, instead of using a regular or high torque gear set and a less powerful spring. Is there something inherently good about short stroking? When you short stroke, you are utilizing less of the cylinder volume, I don't see how this is useful. I've never built a short stroke gear box, but to my understanding to do it properly, besides just modifying the piston, you also have to remove teeth from the sector gear. Otherwise the final tooth on the piston will be hit by multiple gear teeth. Why would you buy a $100 gear set and then chop it, when it's not necessary?

 

Is this a high ROF gun, or is it a DMR? If it's a DMR, you don't need to throw in all these high ROF tricks.

[DSCAllDay]

Interesting parts list. Your piston will almost certainly need to be lightened either way, but the difference between the m170 SS-ed is that it will return faster, thus ENABLE a faster rof. It will not raise or lower your ROF either way.

 

Questionable parts are definitely the bearings, I agree - you just don't need them. You will be putting a lot of stress on them. I advise TerminusX Bushings instead, if you can find them.

Also, the hop rubber. If you are using HS5's hop parts, the aim of the rubber is to seal and prevent blow-by. For that you need a hard rubber, any reason why you decided to go for the soft?

 

I personally don't remember what the MP5 hop is like and have never worked on a G&G one before, so don't know the answer to this, but does the hop unit have enough room and adjustability to even accept an ER-hop? Or are you going for a fixed hop approach? If it does not, you may need some snibbles and may find that there is no way to fit the EM-Nub at all.

Also, what lubricants do you plan to use?

Will the 14awg wire fit inside that Taurus? PTFE is a good choice though.

Also, how do you plan to maintain this build? How and how often will you lube the piston o-ring for instance?

 

This is a pretty heavy build, I mean, it'll require a lot of custom tweaks, polishing and dremel work to even work for a short while. I'd consider building it and starting with a 7.4 and working your way up to 11.1v, checking for Pre-Engagement and wear and carrying on like that, or using ROF limiter in the Cheetah to slowly test your build.

 

And I have not even touched on anything other than the internals, you externals will have to be solid as a rock as well.

 

Good luck though, I have no idea of your experience in AEG work, however a build like this will require it, otherwise it will prove VERY costly. And asking all the questions in the world will not help you when you come to assemble your gearbox and find that one part or another does not fit or your switch assembly is not tripping correctly or your tappet is not returning fast enough. To jump straight into a build like this is ridiculous :/

 

Got it, thanks. Understood. I'm using a soft because people say that hard prommy buckings are for 500+ fps builds. I will do the floss mod though for better air seal. Yes, everything is compatible. I have put about 4 months researching and on other forums/techies. I have changed my mind again and am using an M150 SS'd. I know this will work due to people making the similar build with almost the same parts before. I'm getting it assembled and tuned by mystikal from mystikals fets. He is very very experienced. I have researched this for a long long time. This build has been completed before, I have no doubts atm.

Thanks

[DSCAllDay]

I don't really understand why you'd use a high speed gear set to pull a very heavy spring and then short stroke it, instead of using a regular or high torque gear set and a less powerful spring. Is there something inherently good about short stroking? When you short stroke, you are utilizing less of the cylinder volume, I don't see how this is useful. I've never built a short stroke gear box, but to my understanding to do it properly, besides just modifying the piston, you also have to remove teeth from the sector gear. Otherwise the final tooth on the piston will be hit by multiple gear teeth. Why would you buy a $100 gear set and then chop it, when it's not necessary?

 

Is this a high ROF gun, or is it a DMR? If it's a DMR, you don't need to throw in all these high ROF tricks.

 

Thanks for your input, I will be using a M150 now. I was trying to combat PE. It is a field/ DMR build.

Sorry about the double post. I'm on my phone.

[jal3]

Hey man, i already answered this for you in another thread.

 

Shortstroking is done to:

Give more time for the piston to settle (shorter travel + harder spring). <---primary reason.

Shorten time-to-shoot on semi.

Finetune muzzle energy (one tooth off is less than spring change).

 

Does it shoot faster?

No' date=' if tuned to the same velocity as a full stroke gun, it will shoot slower and stress more than the fullstroke version. Eg. M140 SS5 vs M120 fullstroke.

 

The lonex red piston is a plastic piston.

You must only use a full steel teeth rack piston, such as SHS TT0035.

This is recommended for all SC gears in any setup.

 

M170 spring on 10:1 is insane.

The bearing under spur will die over and over.

The ARL will not work, which results in dead piston, pistonhead and cylinder.[/quote']

 

 

Besides that, i've gone through the list of parts, and whoever greenlighted this selection of parts is not experienced enough to guide people on this.

Furthermore, any high end mechanic would instantly tell you to take your money to a single mechanic and let him build you a complete package instead of having you buy random parts from all over.

 

A build like this (that is, the end goal, not the parts, because the build as listed won't work) requires an insane amount of experience and time to do.

Just because you have money to waste doesn't mean you can do it yourself. Airsoft is not an exact science, and parts rarely fit together as they should.

 

The only way to learn airsoft is to sit down with a ton of guns over a long time. It's (statisticly) not possible to do a highend build right off the bat. And M140 60rps is more than highend, it's right off the charts and into the experimental zone.

 

You're trying to learn how to do it by getting as much input from as many people as you can, then select what you think is right from that info.

But that's not gonna work, because you don't have the experience needed to know what's right and wrong from what you read.

For the same reason i'm not gonna bother advising you technically.

[Im going space]

300ft is 100m give or take, some high end snipers struggle that! I doubt theat this will come anywhere near that.

[Avenger96]

300ft is 100m give or take, some high end snipers struggle that! I doubt theat this will come anywhere near that.

 

It's called an R-Hop. It does incredible things.

[DSCAllDay]

Hey man, i already answered this for you in another thread.

 

 

 

 

Besides that, i've gone through the list of parts, and whoever greenlighted this selection of parts is not experienced enough to guide people on this.

Furthermore, any high end mechanic would instantly tell you to take your money to a single mechanic and let him build you a complete package instead of having you buy random parts from all over.

 

A build like this (that is, the end goal, not the parts, because the build as listed won't work) requires an insane amount of experience and time to do.

Just because you have money to waste doesn't mean you can do it yourself. Airsoft is not an exact science, and parts rarely fit together as they should.

 

The only way to learn airsoft is to sit down with a ton of guns over a long time. It's (statisticly) not possible to do a highend build right off the bat. And M140 60rps is more than highend, it's right off the charts and into the experimental zone.

 

You're trying to learn how to do it by getting as much input from as many people as you can, then select what you think is right from that info.

But that's not gonna work, because you don't have the experience needed to know what's right and wrong from what you read.

For the same reason i'm not gonna bother advising you technically.

 

Well I was guided by the people who made this build previously. This isn't a random mismatch of parts, these were handpicked by the tech who was going to do this for me. He has made tons of builds like this. I've been getting input, but I assure you, I have not been changing much. I went to ASM and the techs there approved it. I'm not going to put this together myself, I'm not kidding myself about that, hell I'm probably not going to even go into full auto very much, if at all. Its not going to 60+ rps, I'm going for 50-55

[original poster]

When I first read 'MP5 DMR' I thought how ridiculous...

 

The more I think about it the more I think how much of an awesome idea it is!

 

Top work

[jal3]

So why are you talking so much about it, instead of just giving him the money and waiting for it to come back?

Why are you making threads on multiple forums asking for help?

Why are you constantly changing your mind about what to put in it if you're not the guy deciding the build?

 

"I'm gonna do M135 fullstroke"

"I'm gonna do M170 Shortstroke 60rps"

"I'm gonna do M150 fullstroke 50rps now"

 

That does not sound like your mechanic making a build at all.

 

How i do it for my customers is usually this:

Customer: "Hey i want a rifle tuned, i want it to shoot so so and with this BB weight at this ROF with this triggerpull length (and so on)"

Me:"Sure, I will use these parts that cast this much, hours will be roughly this much, and it'll take X time before it's done"

Customer: "Ok" *hands over gun*

*2 weeks pass

Me: "Your gun is done, please pay X amount and come pick it up"

 

What you're doing makes no sense. It doesn't fit into the normal process.

Unless it's just shameless self promotion.

Oh yeah...didn't you talk about even making a blog about it on some other forum...?

[DSCAllDay]

So why are you talking so much about it, instead of just giving him the money and waiting for it to come back?

Why are you making threads on multiple forums asking for help?

Why are you constantly changing your mind about what to put in it if you're not the guy deciding the build?

 

"I'm gonna do M135 fullstroke"

"I'm gonna do M170 Shortstroke 60rps"

"I'm gonna do M150 fullstroke 50rps now"

 

That does not sound like your mechanic making a build at all.

 

How i do it for my customers is usually this:

Customer: "Hey i want a rifle tuned, i want it to shoot so so and with this BB weight at this ROF with this triggerpull length (and so on)"

Me:"Sure, I will use these parts that cast this much, hours will be roughly this much, and it'll take X time before it's done"

Customer: "Ok" *hands over gun*

*2 weeks pass

Me: "Your gun is done, please pay X amount and come pick it up"

 

What you're doing makes no sense. It doesn't fit into the normal process.

Unless it's just shameless self promotion.

Oh yeah...didn't you talk about even making a blog about it on some other forum...?

 

Well, lets just say Minerva, the list maker, disappeared due to school and general work. I have slightly different goals now than when I originally spoke to him, so thats the reason I went to get help at the other forums. At AM I met Blake and DE, who had finished pretty much the exact same build, sans the 13.3 and the M135, they went with a 11.1 and M150.

I'm trying to use common sense now to finish and pick the last few parts that I havent bought yet with help from the forums. So doing this I am getting as much feedback as possible, thus the posting everywhere. Also, as you said, this will be high stress, so I'm trying to ask around if people have a setup like this, and if their gun could handle it.

 

I was going to do the m135 with a 11.1, but realized that it wouldnt give me the desired RoF. I then thought to use a 14.8, but realized that it would kill my GB. So I took the middle ground and decided my battery would be a 13.3v. I then realized that I would need a stronger spring to combat PE, so I followed a chart that people gave me regarding PE and string strengths and saw that I needed a M160+ spring for 60ish rps. I got the M170 because that is the only spring above 160 that prommy offered. Then because I realized what a complete mess the M170 would bring me, I'm going to go for a M150, which was already completed by the two people I have talked to. This isnt a normal process actually. The reason for that is didnt know very much about aeg's and airsoft in general before I started, and still do not know much compared to others. But, I know most of the theory, and the parts, due to extensive research, but I'm clueless in a practical sense because this is my first build after all. and I'm trying to get a good build going.

Oh, yeah. That was on Fb. And I realized that it would be completely unnecessary and it would suit me better to do what I'm doing now. xD

 

@ original poster: Thanks.

[WhiteHawksan]

you should generally ignore anything Jal3 says, he's just trolling

 

You're obviously planningo n sinking a fair amount into this build and I still think that the terminusX bushings would be a better choice

[Kenworth W900]

All I can say is 'Gut luck'... 'Thanks, ah ######!' *runs*

 

No, but seriously, you are definitely going to need it.

 

I'm not even sure that what you want is even possible. DMR, 60RPS, M170, 300ft, MP5 - Wah!? These things don't normally even get mentioned in the same threads as eachother. At least you are ambitious, no one can deny that. I just hope your wallet is equally substantial

[DSCAllDay]

you should generally ignore anything Jal3 says, he's just trolling

 

You're obviously planningo n sinking a fair amount into this build and I still think that the terminusX bushings would be a better choice

 

Haha, ok. Thanks. All right. I'll see what I can do. Thanks for the input!

 

All I can say is 'Gut luck'... 'Thanks, ah ######!' *runs*

 

No, but seriously, you are definitely going to need it.

 

I'm not even sure that what you want is even possible. DMR, 60RPS, M170, 300ft, MP5 - Wah!? These things don't normally even get mentioned in the same threads as eachother. At least you are ambitious, no one can deny that. I just hope your wallet is equally substantial

 

Haha, thanks. I'm not sure either. Thing is I'm prolly going to just stick with my 135, add some spring guide washers, add the 13.3v and call it a day. xD PS. I have bought most of the internals and have spent about 750$ already. Trust me, my wallet is feeling the pain.

[jal3]

Well, lets just say Minerva, the list maker, disappeared due to school and general work. I have slightly different goals now than when I originally spoke to him, so thats the reason I went to get help at the other forums. At AM I met Blake and DE, who had finished pretty much the exact same build, sans the 13.3 and the M135, they went with a 11.1 and M150.

I'm trying to use common sense now to finish and pick the last few parts that I havent bought yet with help from the forums. So doing this I am getting as much feedback as possible, thus the posting everywhere. Also, as you said, this will be high stress, so I'm trying to ask around if people have a setup like this, and if their gun could handle it.

 

I was going to do the m135 with a 11.1, but realized that it wouldnt give me the desired RoF. I then thought to use a 14.8, but realized that it would kill my GB. So I took the middle ground and decided my battery would be a 13.3v. I then realized that I would need a stronger spring to combat PE, so I followed a chart that people gave me regarding PE and string strengths and saw that I needed a M160+ spring for 60ish rps. I got the M170 because that is the only spring above 160 that prommy offered. Then because I realized what a complete mess the M170 would bring me, I'm going to go for a M150, which was already completed by the two people I have talked to. This isnt a normal process actually. The reason for that is didnt know very much about aeg's and airsoft in general before I started, and still do not know much compared to others. But, I know most of the theory, and the parts, due to extensive research, but I'm clueless in a practical sense because this is my first build after all. and I'm trying to get a good build going.

Oh, yeah. That was on Fb. And I realized that it would be completely unnecessary and it would suit me better to do what I'm doing now. xD

 

@ original poster: Thanks.

 

Alright that's fair then. This is why you should generally make a specified deal with mechanics instead of buying parts yourself. If you go to a different mechanic, they might tell you to buy new parts (because each mechanic does things his own way), and you're stuck with parts you can't use then.

Or the mechanic is better at sourcing the parts and can get it cheaper for you.

 

I generally agree that it's not a bad thing to know how a hobby toy works, but the time invested doesn't pay off in airsoft. If you don't want to leave it all to the mechanic, you should buy a couple of m4's and a bunch of SHS parts and go nuts with that instead. If you have multiple projects to toy with, you can always put one on the shelf until you find a new solution you have to try out.

I'd suggest starting out with M130 30RPS, then M100 30RPS, then M130 40RPS, etc.

And you test for pre engagement by firing auto through a chrono. If FPS dips at high rof, it needs more work. Always verify that whatever you buy doesn't have this problem. And don't let the mechanic give you a bs excuse.

 

If you want a killer highend MP5 that's not more experimental than functional, go for this instead:

14,4v

21:1

G&P M160 or equivalent winded motor.

M160 SS5

 

That should land you at around 35RPS M140 and have a nice balanced stress on the parts.

This is low enough that your mags will feed properly with heavy BB's.

 

I have a 60rps gun.

Yes it's fun.

No it's not very useful. It goes through mags so fast that laning properly becomes an issue. With a 100round mag it would be downright impossible!

It doesn't feed 0,40's very well at that rof either.

It's the kind of project you take on to push your own limits as a mechanic. It's not really something you'd buy as a customer.

[Samm]

you should generally ignore anything Jal3 says, he's just trolling

 

Well I wouldn't myself, as he's one of the most technically-minded people on here.

 

The only way you're going to get any confidence in customising AEGs is to play about with them mate. Don't spend all your money on high end parts on your first go as you could end up very disappointed.

 

Get some cheap stuff and play about with it first, then you will have more luck putting your theories into practice on more difficult stuff.