Problem in Aiming, GBB Replica

[JevGen]

Hi 

am quite new in airsoft, was wondering about one question.

As my first replica bought FNX-45 from Cybergun, but it seems there is a strange thing.

 

Below you will find to images of targets A4 sheets, both times it was full mag- about 20 rounds, with min or max hop up.

In both cases it was with green gas of 150 psi, 0.25 g BBs and indoor, with about 5-6 m from the target.

 

So i do not really understand why am quite of the target but with very narrow distribution of few cm, so does not seems like coincidence.

Was wondering how i could offset it ?

 

Thanks in advance  

 

[EDcase]

There is something wrong with the hop unit.  The difference between min and max should be MUCH more.

You'll have to take it apart to see.  Its not very difficult and good to know.  Fix could be as simple as re-seating things or hop rubber may need replacing which is cheap.

Look on YT for vids on FNX 45 disassembly etc

[Adolf Hamster]

This is the difference between accuracy and precision

 

Normally we use the terms interchangably but this perfectly demonstrates it.

 

Precision (which is what a lot of times is meant when talking about "accuracy" in airsoft) is the size of your groupings.

 

Accuracy is how close that grouping is to the aim point in this case the bullseye.

 

This is why gun sights need to be "zeroed" so that for a particular person the shot lands where they think its going to land. Kudos on actually noticing it so quickly, as this problem is often the cause of a lot of "take yer ****ing hits" style arguments when folk dont realise the gun doesnt just magically shoot on target out of the box.

 

Most rifle iron sights, scopes and red dots have this functionality built in, however often pistols dont.

 

At best you might be able to tap the front sight left/right (some pistols theyre fixed even if they should be movable) to adjust there.

 

Vertical dispersion on a real handgun is kind of "fuck it, close enough" but in airsoft you can use the hop unit, which is what you were trying to do. As @EDcase says normally you'd expect motion but tbh at 5-6m its probably not enough time for the hop to really be taking effect (normally it only kicks in further downrange)

 

However the simplest fix which works on any gun is just to apply "kentucky windage", ie just aim up and right a bit to account for the shots going low left.

[EDcase]

The groupings look OK.

It does seem to be shooting low.

But the hop definitely isn't working properly.

 

@JevGen Make sure to clean the barrel properly (Ideally with Isopropyl)

[Cr0-Magnon]

Surely the hop doesn't even come in to effect that close? If you think about it, even with hop off most guns will shoot what, at least 15M before the BB drops? Same with max hop, the BB doesn't go vertically up straight out of the barrel. It travels that 15M or so and then arcs up.

[Adolf Hamster]

13 minutes ago, Cr0-Magnon said:

Surely the hop doesn't even come in to effect that close? If you think about it, even with hop off most guns will shoot what, at least 15M before the BB drops? Same with max hop, the BB doesn't go vertically up straight out of the barrel. It travels that 15M or so and then arcs up.

 

in a purely technical sense @EDcase does have a point, the hop should be applying a lifting force from the moment it leaves the barrel. wether or not there's enough difference at 5m for it to shift on paper at that distance i can't really say as the rare times i'm engaging at that distance i'm not even bothering to aim.

[Skara]

17 minutes ago, Cr0-Magnon said:

Surely the hop doesn't even come in to effect that close? If you think about it, even with hop off most guns will shoot what, at least 15M before the BB drops? Same with max hop, the BB doesn't go vertically up straight out of the barrel. It travels that 15M or so and then arcs up.

 

Not quite 15 metres, but you get the point. There is a certain distance in which the BB doesn't seem to be affected by the backspin (varies from gun to gun, but let's say 5/6 metres in which the bb flies in line with the barrel), so a 5 metre range doesn't really show anything (a la Airsoft Mike).

 

To the OP, I would first of all go through 6/7/8 magazines without caring too much about accuracy, then test on a longer range, say 15 to 20 metres, hop completely off vs hop completely on vs hop properly set for the bb weight you're using.

To eliminate external factors, rest the gun on a bench/table/chair and record the results.

 

Also let's keep in mind that:

1. it's a brand new gun, the hop rubber will most likely need bedding in along with purging excess lubricant (you know, some guns are caked in grease/oil from factory for "protection" during shipping);
2. it's VFC OEM'd;

 

[Guest]

19 minutes ago, Skara said:

it's VFC OEM'd;

OP, this is the entire root of your problem Unfortunately.

 

VFC guns look fabulous, but shoot poorly and are unreliable without modification 

[JevGen]

Guys, thanks for your hints

 

What you would suggest ? 

 

Think i have three options:

a) give it back to seller, think such staff should be covered by warranty ? As if this view i see from 5 meters, i a bit afraid what happens at 10? 15 ? I do not have possibility to test, but don't think it will be better - mean it will be worse.

b) try modifications ? but then what kind of modifications you would advise ? Changing the barrel ? hop up unit ?

c) in this specific model i can mount red dot aim, this will help in compensation, however thing this is not really good option as it look so much off the target ?

 

Thanks for advise in advance 

 

[EDcase]

If you clean the barrel and it still shoots the same then you could return it as its not performing as it should.

 

Me personally, I would disassemble it and clean/check everything first and if still shoots that far off then I'd return.

[Skara]

2 minutes ago, EDcase said:

Me personally, I would disassemble it and clean/check everything first.

And void any warranty

[JevGen]

sorry forgot to mention- it was cleaned/ decreased- greased again and try- does not help..

Contacted supplier, they said they will send this part to me

|Therefore we will attach you a Modify Joint hop-up by priority letter so that you can test the performance of your replica with it|

 

Not sure what is this

 

[MadMole]

Nothing wrong with that gun.

 

Short range far too little to show any affect from hop up,  needs 20m plus to even start to see differences, unless you almost block the path by over hoping

Grouping normal, the slight flyers will be down to BB inconsistency  (bet their Blasters!)

Low left is due to jerking the trigger and  perfectly normal  for  most people. Can be trained out

 

seems  they are sending you  a new hop rubber

[Guest]

6 hours ago, MadMole said:

Nothing wrong with that gun.

Well, apart from being a VFC 😂😂

[Davegolf]

@JevGen I have to agree with @MadMole, you need to be testing this gun at least 30M range to see quantifiable differences.

 

It looks to be very consistent, unsurprisingly at 5m range.

 

Load up with 0.2 BBs then set the hop to zero/minimum, fire into the wilderness and you should see the BB curve DOWN sharply.

 

Gradually increase the hop and you should see the BB lift more and more.

[JevGen]

Hi 

Sharing this as hopefully help someone with same issue - below you will find result of two shootings with same gun, same gas but different BBs. Top picture 0.25 BB Bulets, buttom is 0.20 BB from Swiss arms. Distance is about 5 m for both.

 

so that is the reason  

 

i don’t think it is different weight (as it is 5 m to targets and using 125 psi gas), but surface - bb bullets surface feels like “oiled” while Swiss arms a bit more rough .

 

with Swiss Arms very consistent shooting 

[Shamal]

1 hour ago, JevGen said:

Hi 

Sharing this as hopefully help someone with same issue - below you will find result of two shootings with same gun, same gas but different BBs. Top picture 0.25 BB Bulets, buttom is 0.20 BB from Swiss arms. Distance is about 5 m for both.

 

so that is the reason  

 

i don’t think it is different weight (as it is 5 m to targets and using 125 psi gas), but surface - bb bullets surface feels like “oiled” while Swiss arms a bit more rough .

 

with Swiss Arms very consistent shooting 

I take it you regassed mag between firings

 

[Enid_Puceflange]

I wonder if there is a correlation between the polished bbs and the “rougher” bbs in accuracy

Keeping in mind Golf balls are dimpled to increase to effect of spin and purchase in the air etc (grip so to say)

[Adolf Hamster]

2 minutes ago, Enid_Puceflange said:

I wonder if there is a correlation between the polished bbs and the “rougher” bbs in accuracy

Keeping in mind Golf balls are dimpled to increase to effect of spin and purchase in the air etc (grip so to say)

 

i did do the math on the drag crisis for an airsoft bb and no dice.

 

i'd hoped that the transition point would line up somewhere between 280 and 320 fps which might put some actual physics behind marui's fairy dust but alas twas not to be.

 

what's going on is more likely grip levels in the hop, consistency of diameter shot-shot, consistency of mass shot-shot, not having imbalanced centre of mass etc that are the hallmarks of a higher quality ammo.

[JevGen]

1 hour ago, Shamal said:

I take it you regassed mag between firings

 

No, one same charge - one gas charge is enough for about 3 refill of BBs

[Shamal]

1 minute ago, JevGen said:

No, one same charge - one gas charge is enough for about 3 refill of BBs

I think to be a good test you should do both tests with freshly gassed mags. 🤔

Regards 

[JevGen]

Have the same feeling 

nevertheless- learned what was obvious I guess  - don’t buy unknown producer ammo. Those bb bullets were not really cheap by the way- similar to Swiss arms 

[Shamal]

52 minutes ago, JevGen said:

Have the same feeling 

nevertheless- learned what was obvious I guess  - don’t buy unknown producer ammo. Those bb bullets were not really cheap by the way- similar to Swiss arms 

I run with blaster bbs. Not too bothered cause I can't hit squat unless its doing star jumps in front of my barrel lol.

Regards 

Edited February 23, 2021 by Shamal
Spelling

[MadMole]

On 23/02/2021 at 20:14, Shamal said:

I run with blaster bbs. Not too bothered cause I can't hit squat unless its doing star jumps in front of my barrel lol.

Regards 

Thats probably cos Blasters are very inconsistant with loads of random voids inside them. Try some Geoffs, valkyries, or G&G and I bet you see improvement