Is this a good way to swap from CQB to Field?

[blackjack21]

I currently have a great 350fps VFC M4ES. At CQB ranges (70-100 feet) it is dead accurate with stock barrel. I mount a flash light and a red dot and am pretty happy with the gun.

With the Field season starting I would like to get a cost effective swapable Designated Marskman upgrade for my same gun.

I was thinking of getting a 500mm Tight Bore (stock barrel is 363mm) A mock silencer to hide the barrel, an A+ 60 degree rubber and a second VFC hopup unit so I can swap out the barrel and hopup in one go.

I happen to have a quality x4 ACOG (tried it in CQB but it's just to hard to use in low light and close distances.)

So the idea is swap my redot for my ACOG, swapout the barrel and hopup, swap my flash suppressor for a mock silencer to cover the extra 6 inches of barrel.

1. Does this sound like a reasonable upgrade path for field?

2. Can anyone recommend a place that will sell a VFC M4E compatable hopup as well as a good tight bore at a good price? (The madbull hopup for M4 will not fit the VFC model for instance.)

3. What degree of Tighbore do you recommend is there any reason no to get a 6.01?

[lurkingknight]

you'll need to replace your cylinder to support the 500mm barrel. Full cylinder, no opening. This will make some readings a bit wonky when you use heavier ammo with your cqb setup, but it will allow you to hotswap barrel setups. You'll most likely retain your fps though, maybe gain 10-20fps depending on how the air seal works out with the increased air. If you don't change the cylinder, you could lose FPS with your longer barrel.

6.01 is not as tolerant to variations in BB size or dirt in the barrel, they have the potential to jam up more.

A prometheus EG 6.03 is a great barrel. If you ant to save money, I've had good results with madbull python 6.03s.

[blackjack21]

So the new cylinder will be a permanent replacement? I.E. I wil use it for my CQB as well as my Field setup?

[666]

http://www.airsoftcanada.com/showthread.php?t=18038

[lurkingknight]

yes, you'll have to leave it in the gearbox if you want the hotswap barrel option. It's not an ideal setup since you are intentionally mismatching your cylinder air volume to your barrel volume. What happens is with heavier rounds, they will have slightly more time to accelerate since they take longer to get moving...

The anomaly you'll see is that while you may still chrono at 350 with .2s which is 1.13 Joule of energy,but with say a .3 you may actually see higher fps (and therefore muzzle energy) when still expecting to see 285fps at 1.13J. It's an example of what can happen, it will depend on a bunch of variables, air seal, piston weight, spring... it's sort of hard to calculate until you throw it together an actually chrono with different weights of ammo.

What's important is if your indoor limit is 1.13J, you should be chronoing at that or lower with the ammo you are going to use indoors. And why J is important is because that's the statistic that matters for impact rating. It's just that FPS with a known, uniform weight is easier to measure since not all chronos can calculate J.

[blackjack21]

"ASC Thread"

Damn this is complex stuff...

Thanks guys!

[m102404]

I used a longer sig length inner barrel and adjusted the ported cylinder mechbox to shoot 400fps w/0.20's. Then, when I switched to a shorter (just sub CQBR length) inner barrel/hopup I found that my FPS was 340fps w/0.20's

I was using a Madbull JP rifle setup where the outer barrel has various detacheable sections to go from just in front of the gas block out to 15-ish". You could do a CQBR barrel length and then use a suppressor to cover the longer inner for field use.

I did have multiple uppers for a single lower...but in the end it was just easier to drop out the hopup/inner and swap in a different hopup/inner and attach/detach an outer barrel length as needed.

This type of setup worked in a number of M4's that I built.

So...if you're going to do this...take your longer inner barrel length, adjust velocity to your upper field range 380-400 and then use a short barrel to kill off velocity.

[Danke]

If it's dead accurate at 100' why not try it as is outdoors.

[Hectic]

dependimg on what cylender you have will dictate the length of inner you can run.
Most m4 type guns have a 4/5 port so you can go up to 455mm inner
http://arniesairsoft.co.uk/?filnavn=...andbarrels.htm
that said you likely wont see a huge increase in range and accuracy.
even going from 350-400fps wont make a huge difference.
easyest cheapes option would be to buy a 455 mm tight bore and a spare hop up and a barrel extension or mock silencer and just swap barrels and screw on the extension/silence when you play outdoors.
youll gain maybe 10-20 fps a bit of range and some tighter groupings.
just dbl check what cylender you have befor you choose an inner
as some cqb length m4's will have a 3/4 port limiting you to 430 mm.
my stag15 (baisicly an m4) happend to have a 4/5 so i went to a 460mm 6.03 and that works well but again not a huge improvement over the stock 363mm aside from tighter groups at range.
most mildly upgraded aeg's between 350-400fps have about that 100-150ft of good useable range, to increaee that try using .28 or .30 bb's if you hop up can provide enough lift for them and thatll give yo
more range.

http://www.airsoftforum.com/board/lo...x.php/f85.html
check out sections 2,3 &5
this will show you that heaver bb will be beter then tryin to squeeze out 50fps more. Say you increase to 400fps and still fire .20 youll loose that 50fps in the first 20-30 feet after the bb exits the barrel swap up to .28 or .30 and youll maintain a higher speed longer, after 50 feet or so they will be goin tue same speed but the .20 will have way less power and start to slow down fast, the .28 or .30 will maintain speed and power longer thus increasing your range even with the same fps to start with.
i dont see a need for you to upgrade the spring just upgrade the barrel and you bb weight and your knowlage and youll see a spring swap isnt needed.

[ThunderCactus]

Here's a crazy idea, try using your gun in the field first before deciding its not good enough.
If you still want to upgrade after, start with the hop rubber. Either Rhop, PDI-W or firefly.
A common misconception is that a longer barrel will magically increase your range and accuracy. This is largely false.
A BB becomes stabilized in your barrel around the 380-440mm mark (I've heard as low as 260mm), and anything beyond that just increases the chance of destabilizing the BB.
What's important is the concentricity or quality of the barrel.
You can use a 6.08 x 420mm barrel and have amazing range and accuracy.
6.03-6.05 is generally what's recommended
6.01 is built specifically for fps, its not for accuracy, they're useless


So test gun first
Hop rubber
363-420mm barrel, swap cylinders and check your mechbox for any air leaks while you're in there

At 350fps you should use .25g BBs, which should give you real good range. For more accuracy you may have to upgrade to 380fps (on .2s) and use .28g BBs

[m102404]

Absolutely...match the weight of the BB to the purpose and get your hopup tuned in (which you can really only tell at range/distance).

Having one set nicely with 0.20's at your CQB FPS and another set to your outdoor 0.25+ weight is really handy. (my fav local CQB place is 0.20 only)

[lurkingknight]

I've said it before, there is no measurable difference in accuracy between my 407mm prometheus 6.03 barrel vs my madbull 247mm 6.03. Both reach 60m accurately.

but, if you want to do it, cylinder mismatch is how you do it.

[blackjack21]

Ok well I will have my first field game in a few weeks so maybe I will just try .25 bbs (.2s are for CQB around here) and my ACOG and see how it goes for the first time.