FPS Consistency

[Goge]

I've searched but haven't found out how.

I read all over the boards people reporting FPS consistencies of +-5to10 FPS in their guns. I have never seen this in any gun I've chrono'd. It may shoot like that for a handful of shots and then it will raise or lower by 20 and then shoot consistently at that range for another handful of shots. Then their are the outliers that will shoot +-50 fps maybe every 30 shots. Guns with full tuneup kits with all the same brand, metal one piece hop-up units and tight bore barrels, stock CA full metal body M4's, and stock krakens all do this.

Am I using the chronograph wrong or am I interpreting what people are calling consistency wrong?

If people are achieving a consistency of +-5to10 FPS over a whole low-cap how are they doing it?


Much appreciated,
Goge

[godwin]

I have 371 fps on my main AEG now, +/- 2 fps max.

Some points for consistency:
a) Use a good chrony, the best is the XCortech X3200. Madbull V1/V2 and others are most crap.
b) Use good quality BBs. With bad BBs i get only 360 fps +/- 8 fps...
c) make sure your system is 100% leakproof
d) use a tightbore barrel
e) use a good quality spring (=same power every time)
f) use a spring-guide with bearing, bearing in the piston too (= spring doesnt warp => not the same power if warped)

[ThunderCactus]

It's all about getting a good airseal

[Crunchmeister]

I get +- 5 fps on my AEGs. I've had the chrony guys at several games comment on the consistency of my muzzle velocity. It's about air seal and spring consistency. Using a quality spring along goes a long way, but for me it's also about installing ball bearing spring guides and piston head. This prevents torsion in the spring as it compresses, causing it to decompress in a much more consistent manner. This, combined with a good air seal can give you a very consistent gun.

[Amos]

My G3 is +/- 2

my VSR is +/- 0.2X

[Goge]

Originally Posted by godwin

I have 371 fps on my main AEG now, +/- 2 fps max.

Some points for consistency:
a) Use a good chrony, the best is the XCortech X3200. Madbull V1/V2 and others are most crap.
b) Use good quality BBs. With bad BBs i get only 360 fps +/- 8 fps...
c) make sure your system is 100% leakproof
d) use a tightbore barrel
e) use a good quality spring (=same power every time)
f) use a spring-guide with bearing, bearing in the piston too (= spring doesnt warp => not the same power if warped)

Can anyone point to guides that explain how to check this? I've seen this recommended many times but I can't find any thorough guides.
I've done B through F but checking for 100% leak-proof seals.
Unfortunately I'm using a Madbull V2 and don't have the money for another chronograph, are there any ways to mitigate what ever disadvantages the Madbulls have?

Amos, can you explain how you achieved these awesome results or have you posted how anywhere else already that I can read up?

Thanks

[AoiShikaku]

Agreed with a lot of people that listed above.

I made the mistake of picking up a crap chrono and ended up junking it the same week I bought it. I've had deviations in my stock guns (TSD/Well L96 [spring], KJW 1911 MEU [gas], ICS M4[AEG]) but after a bit of maintenance, cleaning, minor/major upgrades, and quality BB's my shots became a bit more consistent. I woulr range from 10-30 FPS difference before hand and went down to 0-5 FPS difference


So overall to get a consistent FPS (from my experience)
1. pick a good chrono
2. do what you can to your gun to ensure consistent shots
- Clean your gun
- Air Tight Seal
- Proper Oil and Greese (don't over do it)
- Quality barrel, spring, cylinder, bucking, etc.
3. get quality BB's
4. Maintain you gun
- Make sure the spring is released and not cocked back when not in use
- Treat it like any real firearm. Without proper maintenance you'll get inconsistency from wear and tear, dirt, etc.


I'm sure there are other that may say otherwise or have more to add, but I would say take all the advice you can get and try em all. The more options the more chance at maintaining consistency.

[Azathoth]

80% of my 'inconsistency problems' are related to the Chrono. On the terrible madbull chrono's you can get very wild readings. They even change if you shine a flashlight at at the sensors. Generally the other 20% is ammo.

It's like measuring your weight on a your run of the mill digital walmart bathroom scale vs doing it on a medical scale that is properly balanced.

[Amos]

I'll be making a video series soon on upgrading....

Just gotta find the time and get a tripod

www.youtube.com/amosv2

[godwin]

How to get 100% airseal:

I dont know who this pic made, but it is really good. If somebody know - tell me please.


Its a big chapter and i could write some pages how to test and fix things.
Lets keep it short:

Test - if you know other ways to test the points, tell us please:
1) What? Cylinder/Pistonhead
Parts needed for test: Cylinder + Piston with Pistionhead
How to: Seal one end of the Cylinder with your hand/rubber pad and press the cylinder in
What should happen: air should compress and you can not move the piston further in
2) Same like 1, seal cylinder-head-nozzle with your thumb
3) Insert P+PH, Cy+CyH, tappet plate and nozzle in your gearbox, move tappet plate with nozzle forward (shooting position) and presss piston into the cylinder. Most people loose fps here
4) assemble the whole system, fire semi till the nozzle is in the forward position. light with a bright flashlight into the uploading nozzle (coming from the mag) and look into the barrel - you should not see light.
Other test: Hold the nozzle on the bucking lips and blow into the barrel. Measure how far the nozzle touches the lips.
5) Hard, also testet with the 2nd test at 4.

How to fix?
Lots of ways, tell us what doesnt seal, we tell you how to fix it.

[Amos]

Originally Posted by godwin

How to get 100% airseal:

I dont know who this pic made, but it is really good. If somebody know - tell me please.


Its a big chapter and i could write some pages how to test and fix things.
Lets keep it short:

Test - if you know other ways to test the points, tell us please:
1) What? Cylinder/Pistonhead
Parts needed for test: Cylinder + Piston with Pistionhead
How to: Seal one end of the Cylinder with your hand/rubber pad and press the cylinder in
What should happen: air should compress and you can not move the piston further in
2) Same like 1, seal cylinder-head-nozzle with your thumb
3) Insert P+PH, Cy+CyH, tappet plate and nozzle in your gearbox, move tappet plate with nozzle forward (shooting position) and presss piston into the cylinder. Most people loose fps here
4) assemble the whole system, fire semi till the nozzle is in the forward position. light with a bright flashlight into the uploading nozzle (coming from the mag) and look into the barrel - you should not see light.
Other test: Hold the nozzle on the bucking lips and blow into the barrel. Measure how far the nozzle touches the lips.
5) Hard, also testet with the 2nd test at 4.

How to fix?
Lots of ways, tell us what doesnt seal, we tell you how to fix it.

Souly based on your user name:

This sounds like Nazi propaganda.

[godwin]

Originally Posted by Amos

Souly based on your user name:

This sounds like Nazi propaganda.

Dont understand this, what do you mean?

[Jackarutu]

Only a child stolen by gypsies and raised in a caravan like AMOS would recognize that Harold Godwin was sent by the Nazi to take over England.

Harold Godwinson (or Harold II) (Old English: Harold Gōdwines sunu) (c. 1022 – 14 October 1066) was the last Anglo-Saxon King of England.[1] Harold reigned from 6 January 1066 [2] until his death at the Battle of Hastings on 14 October of that same year, fighting the Norman invaders led by William the Conqueror during the Norman conquest of England. Harold is one of only three Kings of England to have died in warfare, alongside Richard the Lionheart and Richard III.

[Amos]

..... not quite.

http://en.wikipedia.org/wiki/Godwins_law