Picking CM16 Dmr

[SuperHog]

bradmc,

Your original intention was to spend $$$ to gut out the internals for your project. So just ignore my suggestion. Just get a that CM plastic gun, don't let my opinion change your mind.

Maybe those that post here, own CM, but I don't. I don't know why you don't consider a G&G SR25 and save the headaches.

I do have a VFC SSR and a G&P SR25 out of the box a DMR. The only thing I did was a new inner barrel and new hop up.

[grantmac]

An AEG with a long inner barrel isn't a DMR. Having a DMR then using it like a regular AEG doesn't make you a designated marksman.
Try learning the role before changing equipment.

[lurkingknight]

the term CNC is also used as loosely as polymer.Especially in airsoft.

Just as all plastics are polymers; not all polymers are created equal,

Not all CNCed metal is equal.. and not all CNC process is what you think it is.

There's cast parts that are finished by CNC... pot metal with machined finishing to get in certain things... such as a computeriszed drillpress to cut in the pinholes.

Then there's CNC out of BILLET. which is a single piece of material, be it polymer, brass, wax, steel, what have you.

They take a piece of solid stock and the computer guided machine cuts your shit out of it. That would be the strongest.... that does not exist in airsoft.

However, CM plastic bodies are just ABS. there are other plastic bodies such as nylon fiber reinforced plastics/abs that are much stronger, but again, notall nylonfiber is created equally... dpending on fiber count, composition of the abs element, casting quality, mold quality, temperature control of the plastics when they're injected into the molds.. etc.

Loose tolerances are what you're most concerned about. You can make a gun accurate, but what you should care about is making it precise. To quote someone I know who was a realsteel shooter in the military : Accuracy is a product of the shooter -- precision is a product of the weapon.

Accuracy becomes easier to get when the gun is more precise. Meaning if I put the gun in a vice on a bench, at x meters it will shoot a tight, predictable grouping. Meaning that as a shooter, I can rely on the gun to put rounds exactly where I want at distances I know it can reach out a, that's where I can be an accurate shooter.

First order of business for precision in your weapon is air seal, after that it's application of hop and barrel bore consistency. Using quality heavy rounds will also increase precision.

I did not say, barrel bore diameter, hop up unit or barrel length. These have not shown any definitive indication that a gun is more precise in the dozen or so guns I've built for people this year, or the other countless guns I've worked on for other people.

Unless there is something malformed in those components, there's no reason to change those parameters.

My 30$ madbull python 247mm barrel shoots as precise as my 80$ prometheus eg 407mm. Both are able to put rounds through car windows or hut doorways at 70-80m on target.

[SuperHog]

Originally Posted by lurkingknight

They take a piece of solid stock and the computer guided machine cuts your shit out of it. That would be the strongest.... that does not exist in airsoft.

If you are referring to ACM (China) which is all pot metal, then it doesn't exist.

But there are many aftermarket companies that really do full CNC billet machining like the following and more.

Polarstar (USA
Wolverine (USA)
SPEED (Canada)
Madbull (Taiwan)
RA Tech (Taiwan)
Angel Custom (Taiwan)
Modify (Taiwan)
FCC (Hong Kong)
UAC (Hong Kong)
Airsoft Surgeon (Hong Kong)
Laylax (Japan)
PDI (Japan)

[ThunderCactus]

I should add, just because something is machined from billet, still doesn't necessarily mean it's good.
For example, angel custom is garbage.

[L473ncy]

I'd wait for TC to get in on this but what are they machining the CNC billet from? You get back to the problem of "CNC metal". Is it Carbon steel, or another kind of alloy steel? I had a steel hinge for my backyard gate fail on me because we were loading it with too much shear force (the new gate door was heavy) or maybe it wasn't heat treated properly or had too much/little carbon in it or something.

EDIT: OP, I could also mill things on a lathe but doesn't mean that I'll get any sort of precision, if I'm lucky I *might* be within 30 thou of what I want.

[bradmc]

holy crap, thanks for all the good responses guys. Ive decided just to upgrade my metal non blowback mp5 I currently have and spend the money I would spend on a cheapy M4 on upgrades. I admit, I fell victim to all those flashy DMR youtube vids but you guys are right.

I am ordering some 9.4's from Elite in the states with some dean connectors. I am either going to just buy a complete Lonex gear box or the lonex shell and mix match some parts. I am going to upgrade my barrel on my MP5 to a 6.03 330mm. Only thing I am still considering is the motor. I am looking at the Lonex infinite high speed.

What you guys think? more realistic?

[L473ncy]

If you're going to go 9.4V why not go 7.4V lipo? They're cheaper, and provide arguably the same performance (except when you start to get Vdrop and that's when you change to a new battery and put the old on on the charger).

Also, always go for off the shelf drop in solutions (ie. complete gearbox), there's no point in dicking around inside the gearbox if you don't know what you're doing. I don't recommend the high speed motors because IMO they just make you into a BB hose, I'm perfectly fine with my TM EG1000 motor which nets me more or less what a RS AR15 shoots at (~750-900 RPM or 12-15 RPS).

[grantmac]

If you are looking for trigger response then what you want is a high torque motor along with standard or higher speed gears and fairly high voltage.

A high speed motor with low ratio gears can produce a high cyclic rate on low fps and voltage but it will never have the trigger response with a heavier spring.
TM high cycle is a classic example of that set up.

Grant

[ThunderCactus]

You can get pretty high ROF using a high torque/moderate speed motor, 13:1 gears and just a 7.4 lipo

[bradmc]

Originally Posted by L473ncy

If you're going to go 9.4V why not go 7.4V lipo? They're cheaper, and provide arguably the same performance (except when you start to get Vdrop and that's when you change to a new battery and put the old on on the charger).

Also, always go for off the shelf drop in solutions (ie. complete gearbox), there's no point in dicking around inside the gearbox if you don't know what you're doing. I don't recommend the high speed motors because IMO they just make you into a BB hose, I'm perfectly fine with my TM EG1000 motor which nets me more or less what a RS AR15 shoots at (~750-900 RPM or 12-15 RPS).

I have heard bad things about lipo. Exploding issues and stuff. I read that you cannot use them to empty otherwise they can overheat and leak or explode. Not sure if it is true, just stuff I have picked up on forums

[bradmc]

Originally Posted by grantmac

If you are looking for trigger response then what you want is a high torque motor along with standard or higher speed gears and fairly high voltage.

A high speed motor with low ratio gears can produce a high cyclic rate on low fps and voltage but it will never have the trigger response with a heavier spring.
TM high cycle is a classic example of that set up.

Grant

Is a 120 considered a heavy spring?I thought that was middle of the road. What RoF can one expect? The new piston in the box is also rather heavy for a super high rate setup. Something to keep in mind.

[ThunderCactus]

Despite seeming scary after reading this FAQ, lipo batteries are far safer than you think. They tend to give you a lot of warning before anything bad happens.
http://www.airsoftcanada.com/showthread.php?t=156571
Also, they DO NOT explode. They just don't. They can smoke and vent, but you have to be TRYING to get it to burst into flames.

And keep in mind the advantage of lipo is in it's amperage. You'll be able to actually use the torque of a motor. Otherwise, with a mini Nimh, you'll have to pay attention to what gear ratio you're using.

[L473ncy]

Nah... Lipo's are fine.

Although I did have one vent and bulge on me randomly and I just tossed it in some snow, nothing more came of it. I don't know if I have the picture anymore though, I'm on vacation at the moment.

Also yes don't empty it. It needs a minimum voltage to be able to charge back up (although there are tricks you can do with smart chargers like "jump starting" it on NiMH mode for a minute to get it to that voltage then balance charging it the rest of the way). You'll be able to tell if you're running it down though, there's a marked difference when the voltage starts to drop and that's when you know to switch out batteries.

[lurkingknight]

lipos are only dangerous if you're grossly incompetent and negligent with their use and care..such as putting giant motor on it connected to a short gear set with heavy spring on the tiniest stick lipo you can find. That's bad.

Just as bad as throwing it on a crappy wall charge with no auto shutoff or balancer.