GenNex- Excellent Choice for New Shooters

[narach93]

Well said Basuda. This kind of healthy hobby keep all of us fit, agile, and our sense of humour too.
Regards

[targetpoint]

Dear friends,
I made a video of recoil test of my Gennex.Don't know how to post the link of youtube video here in this forum.
You can see the video by writing"Recoil test of self tuned Gennex" on YouTube.
Thanks.

[vsraja]

It is no wonder a low powered air rifle will perform smoother and pleasant to shoot.If you need that experience,there is no need to purchase another rifle.You can simply reduce some power of your air rifle by replacing the spring with smaller spring or removing some coils from the old springs.By doing these tuning will make your gun even more smoother than gennex or any other low powered air rifle.But we dont have option to increase the power of these gennex or other low powered air rifle to the level of normal full powered air guns.

[targetpoint]

Dear vsraja,
Each airrifle of sdb stable is prepared for seperate purpose.Who need power upto 15fpe should buy Artemis and if anyone opt for low powered happy shooting then should go for Gennex.There is also option for 12fpe.
Then it is useless to buy 15fpe Artemis and remove the coils or using weak spring to make it 6fpe.
Believe me once anyone started using Gennex he will become diehard lover of Gennex.
Don't take it otherwise dear.
Shoot less but shoot class.
Thanks.

[satvender]

Dear vsraja,
Each airrifle of sdb stable is prepared for seperate purpose.Who need power upto 15fpe should buy Artemis and if anyone opt for low powered happy shooting then should go for Gennex.There is also option for 12fpe.
Then it is useless to buy 15fpe Artemis and remove the coils or using weak spring to make it 6fpe.
Believe me once anyone started using Gennex he will become diehard lover of Gennex.
Don't take it otherwise dear.
Shoot less but shoot class.
Thanks.

well said!!

[Basu]

Dear Target point,
Thanks for putting the matter under right perspective.
For that I have two ARs.
One for power & other for smoothness.
Artemis is close to 15 fpe.
Sport is close to 13 fpe.
GenNex is close to 7 fpe.
Cutting coils will sure smoothen the shot cycle but it loses it's originality.
But I love GenNex most.....hah..ha..ha....

Basu

[Basu]

GenNex with SDB recently developed Spring delivering solid sweet punch.
It reached upto 700 fps with Unitedshot pointed 7.2 gns or 8.0 ftlbs energy.
With FORCE 9.4 gns it returned 6.7 fpe which is good enough for an AR weighing 2.7 kgs.

Basu

[prashantjha19]

GenNex with SDB recently developed Spring delivering solid sweet punch.
It reached upto 700 fps with Unitedshot pointed 7.2 gns or 7.7 ftlbs energy.
With FORCE 9.4 gns it returned 6.7 fpe which is good enough for an AR weighing 2.7 kgs.

Basu

Great to hear that, Basu da!

Pls could you share the specs of this new SDB spring?

Also, I found Vsraja's suggestion to alter spring specs pretty valid and egaging for those keen on tuning their ARs with different specs, and getting the feel of different set ups. It does add to enriching personal experience and learning.

Look forward,
Regards,
Prashant

[Basu]

New spring of my GenNex has following specification :
Wire dia - 2.8 mm .This is unusual earlier it was 2.9 to 2.95 mm.
Free length - 21 cms.Earlier it was 25 cms.
No.of coils - 25.5 no's.Earlier it was 30 coils.
ID - 13.5 mm.
This leaves the opportunity to use preload , if required.
I think this is a tireless spring and it should last much much longer .
For Artemis & Sport also they developed spring with wire dia 3.15 mm.but I do not have other specifications.

Basu

[targetpoint]

Dear Basu Sir,
It is absolutely a good news that SDB is making their own mainspring that too for each model.I am interested in installing the one which you installed in your Gennex.
Thanks.
Shoot less but shoot class.

[prashantjha19]

New spring of my GenNex has following specification :
Wire dia - 2.8 mm .This is unusual earlier it was 2.9 to 2.95 mm.
Free length - 21 cms.Earlier it was 25 cms.
No.of coils - 25.5 no's.Earlier it was 30 coils.
ID - 13.5 mm.
This leaves the opportunity to use preload , if required.
I think this is a tireless spring and it should last much much longer .
For Artemis & Sport also they developed spring with wire dia 3.15 mm.but I do not have other specifications.

Basu

Thank you, Basu da, for your revert. Much appreciate.
The specs are quiet novel (unusual, going by the specs of most of the in-vogue ones).
I am saying novel, because it is a pretty stiff spring for its size.....with its rate in the range of 5.36N/mm (which is higher than SDB's old full sized spring model 40 coil 3.2mm WD ).
Also, with just 77 mm coil bound length (assuming 27.5 total no. of rings), while there would be a lot of scope for preload, I do not think it will give you a smooth shot cycle behaviour in an essentially 6fpe gun. But pls do test it with some added preload when you have some time, and let us know the gun's cycle.
What is the total spring room at lock up in Gennex please? And what is its stroke, Basu da? Do pls tell us.

Thanks again.
Regards,
Prashant

[Basu]

The stroke length of GenNex is 5.5 cms , so far I can recall.
I have no data in Newton/mm about energy.
It gives a feel of earlier fresh spring of SDB while cocking.
Earlier spring had lost 20.8% of it's free length over 3000 shots.
But this new spring is different , I guess it may lose max 6% of it's free length.
I used 7up bottle's body as sleeve to zero the transverse vibes which worked fine.
I hope this new spring can give service much longer.
Shot cycle is smooth yet little more hold sensitive than earlier spring.
I do not have space to test the accurate of GenNex so I borrowed pics.form Dr.Dikpati's GenNex accuracy testing results.

Basu

[prashantjha19]

Thanks, Basu da.
No wonder, with this stiffer new spring, you would get the feel of the old one in its fresh state! And the increased hold sensitivity with the new spring may only be confirming the stiffness of the new spring.

As you say, the stroke is 55mm, and assuming this to be so, + assuming that the gun is 33% energy efficient (pretty decent for a .177 local gun!!).... Gennex will need preload in the range of 50mm with this new spring to get ME in the range of 7.6 to 8 J. I think the stated output of Gennex is in that range. I trust SDB has resorted to 25mm bore for all its new gen guns.

Also, I have found that while shorter and stiffer springs (like this new one) give a snappier and quicker shot cycle, increasing the piston weight is an effective way to make the shot cycle smoother, more tamed and less hold sensitive.
Thank you again and regards,
Prashant

Added in 4 minutes 33 seconds:
And, of course the accuracy test confirms that the gun performs fabulous....8 of 10 landing a sub-one inch at 19mtrs is terrific indeed!!
Great stuff!!
Regards,
Prashant

[targetpoint]

First of all I will like to thanks Basu Sir for giving me valuable tips while tuning my Gennex.
Dear friends,I had to change the mainspring of my Gennex due to failure of Cherokee 27.Actually it was my fault as I neglected the important part of finishing the spring ends.
But this time I decided to use gsmith 27.After removing few coils I gave a good finish to spring ends.Used moly for lubrication.
Gennex is meant for accuracy and I get for what I was looking for.

Added in 3 minutes 38 seconds:
I coin I used here is the smallest Re1 coin to cover the grouping.Gennex is as accurate as the man behind the trigger.It is one holer at the distance at which a man is comfortable at.
Thanks.
Shoot Less But Shoot Class.

[Basu]

Dear Targetpoint,
22.5 cms free length of Gsmith 27 is good enough for required power and accuracy.
I see it in the vicinity of 6 fpe max.
I will not be surprised if you present us half of this group size after 500-600 shots.
Great going......

Basu