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C4 Graphite Accuracy

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
The spear I use at the moment (I changed 1 month ago) is new (Rabitexh 150) but the flopper is a bit too tight and does not close completely. It seems the accuracy decreased more since I use it. I have another one I will try today, with same rubbers.
 
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The picture of the Graphite above is an old model, the line release is now integrated into the handle.
and the rail is more a rest tab than a real track.
 
You can see on the photo that the track is flat and the release is different.
 

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The spear I use at the moment (I changed 1 month ago) is new (Rabitexh 150) but the flopper is a bit too tight and does not close completely. It seems the accuracy decreased more since I use it. I have another one I will try today, with same rubbers.
Well that's not good. There are some good videos on YouTube on tuning your flopper, not least the one by Rob and another good one by Daniel Mann.

But sounds like Rob's original point about the spear being too long if you have no rail might also be a problem that needs to be addressed. Tune the flopper first, it's free ;)
 
If you dive in very warm water the rubber will work better. In colder water rubbers do lose power. Try softer/longer rubbers if the water you dive mainly in is very warm. We have only recently picked up on just how much of an effect water temperature has on rubber performance.
 
The rail on my Grap is pretty much flat there is no real guide and it is actually make loading more complicated because you have to guide the spear right into the handle and sometimes you have to try several times, not easy when the surface is a bit rough , or when you’re drifting in a strong currant. The only real guide I see Is at the muzzle and it’s 10 mm long.
Regarding possible overpowering, I used the recommended length of rubber from C4:
610 and 630 mm of 14.5 mm for a 120cm gun.
The surface of the rail still supports the shaft even if it is flat. On the Urukay the track is cupped with curved ridges on either side in cross-section.
C4 Urukay rear lhs R.jpg

C4 Urukay wide shot R.jpg

C4 Urukay muzzle tip.jpg
 
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On long tube guns with no rail the shaft can sag if it is long and thin in diameter and only supported at the sear box and muzzle ends, but any intermediate rail on the barrel will hold it up and in some early tube guns a mid-handle with a short guide section on top did that, although it was not ideal. The rail gun, when it first appeared, had a flat rail as part of the barrel alloy extrusion, although plastic guide tracks had preceded it on tube guns such as JBL (ex Swimaster Voit), however the latter are not euroguns.
 
I have the same gun with the same problem. 20+ years spearfishing and have re-rigged it in a multitude of ways (changed power ratio and spear diameter) and have played with the wrap (double wrap normal and reverse wrap single). It consistently shoots about 15cm to the left of a target at full range of a single wrap. I first suspected the angle of the handle may be changing the shot as it releases, however I changed my grip a number of times to counter this and the problem remains.
I teach spearfishing courses, and so this gun now stays at home to look pretty in the corner of my shed.
 
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Thanks everyone for your advice. I will work on my flopper, then with a longer spear.
I will keep you posted on the results.
 
I’ve seen videos of guys using it with accuracy. I don’t get why it does not shoot straight
 
Hi all,

Just saw this (deeper blue notifications email)...
Graphite 116 is my go to gun! I also have a Grahite 83 and had Urukay 105 and 120 so I know how these 2 models work :)
I'll carefully read all the comments and then try to help.
I can shoot mine accurately... I use 2x14mm bands at 340-350% and a 150 7mm spear.
 

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I have the same gun with the same problem. 20+ years spearfishing and have re-rigged it in a multitude of ways (changed power ratio and spear diameter) and have played with the wrap (double wrap normal and reverse wrap single). It consistently shoots about 15cm to the left of a target at full range of a single wrap. I first suspected the angle of the handle may be changing the shot as it releases, however I changed my grip a number of times to counter this and the problem remains.
I teach spearfishing courses, and so this gun now stays at home to look pretty in the corner of my shed.
Would you like to sell it? I have a friend wanting one...
 
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Ok, I've read it all...

Bands:
I'm using the gun with 14mm bands but I also have used it with 16mm bands, both with small ID... 63 and 61 cm would be too short for small id bands for my spear... In a notched spear you lose a lot of band stretch if the notches are far from the mech and there's a big space in between them... I load both bands at last fin. Measure from band hole to the fin/notch you intend to load it to, multiply by 2 and divide by the coefficient (I'd recommend 3.3-3.4 for good power to band life ratio).

Spear:
This is almost like discussing witch team is best :)
I prefer shorter thicker spears. I don't aim using spear tip - I use gun body/spear body... 150x7mm is exactly what I have. Flopper should be tunned but that wouldn't explain side variations (only vertical) unless you shoot like a gang member :D

Now what I think could be at play here:

How is the gun's balance?
Some graphites are muzzle light... I had that with my 83 and it was repaired under warranty.
If you see pictures of Graphites and Mr carbon/iron from spearos, you'll see quite a few with lead pieces glued at the front. I think C4 is more onto of it now but some guns were not properly balanced... Do you have to force the gun down, rotating your wrist down to keep it in line? Once you take the shot, the gun goes muzzle up? If so, front is too light! A longer spear would make it better tracking and aiming since you'd have more weight at front (Look at me commenting on Mr Rob Allen advice - I'll feel special the whole day :) ) but once you shoot, the muzzle will go up and mess spear trajectory...

Let me know about these...
If nothing works I have a friend wanting one of these (fell in love after trying mine) if we can work out a deal :)

Cheers
 
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I’ve seen videos of guys using it with accuracy. I don’t get why it does not shoot straight
Have you tried contacting C4 about this? Might be worth asking. Perhaps even include a link to this thread? Perhaps something to do with muzzle balance, as somebody mentioned above?

Over the years, I noticed several forum members get a C4 speargun but they don't seem to stick with them. Which surprises me as I would expect them to be the ultimate in versatility. Perhaps fear of loss/damage - or perhaps difficult/different to shoot accurately?
 
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Ok, I've read it all...

Bands:
I'm using the gun with 14mm bands but I also have used it with 16mm bands, both with small ID... 63 and 61 cm would be too short for small id bands for my spear... In a notched spear you lose a lot of band stretch if the notches are far from the mech and there's a big space in between them... I load both bands at last fin. Measure from band hole to the fin/notch you intend to load it to, multiply by 2 and divide by the coefficient (I'd recommend 3.3-3.4 for good power to band life ratio).

Spear:
This is almost like discussing witch team is best :)
I prefer shorter thicker spears. I don't aim using spear tip - I use gun body/spear body... 150x7mm is exactly what I have. Flopper should be tunned but that wouldn't explain side variations (only vertical) unless you shoot like a gang member :D

Now what I think could be at play here:

How is the gun's balance?
Some graphites are muzzle light... I had that with my 83 and it was repaired under warranty.
If you see pictures of Graphites and Mr carbon/iron from spearos, you'll see quite a few with lead pieces glued at the front. I think C4 is more onto of it now but some guns were not properly balanced... Do you have to force the gun down, rotating your wrist down to keep it in line? Once you take the shot, the gun goes muzzle up? If so, front is too light! A longer spear would make it better tracking and aiming since you'd have more weight at front (Look at me commenting on Mr Rob Allen advice - I'll feel special the whole day :) ) but once you shoot, the muzzle will go up and mess spear trajectory...

Let me know about these...
If nothing works I have a friend wanting one of these (fell in love after trying mine) if we can work out a deal :)

Cheers
Looks like me! I missed my target with the spear flying way above it each time (a 2L milk bottle) while I was aiming to the centre from 3-4 m.
i tested with a longer spear (actually a slip tip threaded head) and was straight in the center.
So more weight seems to improve my accuracy.
 
From the sounds it, there is nothing radical with the rigging setup to cause this.
I’d be looking at two things.
First is your right elbow (assumes right handed!) making sure it is locked and is not ‘giving‘ during the shot. I had a similar problem years ago and filmed myself shooting in my pool and worked out that shots that drifted right were due to my elbow not being locked and during the shot, the recoil would cause the right arm to collapse a bit, as my hand came back toward me, changing the angle of the gun and the trajectory of the shaft. When the elbow is completely locked in, you feel the gun stay on line and see the shaft fly dead centre.
The second thing is the handle on the c4 is not very likely to match the shape of your natural grip. Customising your handle to perfectly fit your grip will reduce the movement of the gun during the shot as there are no voids in your grip for the recoil to push the handle into which can cause drift.
So maybe try a really firm and locking in your elbow during the shot and see if that helps.
 
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Everything was fine previously with my Riffe Eurogun or my RA tuna roller. My elbow is 100% locked I checked that. I changed the grip a bit too, 1 washer at a time.
 
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