9 replies to this topic

[henryED86]

I want to increase around 15-20 FPS to my KWA  SR10 without reducing the life and reliability of the gun.

Can an increase in  FPS ( from mods other than a spring upgrade) cause more gearbox wear and tear ?

[Viet]

the only real way I can think of to get an increase of that little in your gun would be to get a tightbore barrel and or increase barrel length.   Spring changes would change your FPS too much and it would be more trouble than its worth.  Is there a particular reason why you want 15-20 fps increase?

[gcw360]

Viet, on 31 July 2012 - 03:51 PM, said:

the only real way I can think of to get an increase of that little in your gun would be to get a tightbore barrel and or increase barrel length.   Spring changes would change your FPS too much and it would be more trouble than its worth.  Is there a particular reason why you want 15-20 fps increase?

Additionally, a lighter piston can increase your FPS a bit.

[Dirt Bag]

What about the danco #14 o ring?

[henryED86]

I just want to have the optimal FPS to use 0.30 BBs and not compromise range ...I haven't seen any cons of using 0.30 though.

[henryED86]

I guess any mod behind the gearbox( spring , piston , etc.)  would add more stress to the gearbox,  what about an o ring?

[vanevery]

A  thicker bucking, tight bore inner barrel and a new #14 Danco O-ring will put you at your performance goal.
You gotta ask this question though: Is the cost vs performance worth it for 20 extra fps?
Gearboxes will wear out no matter what. Don't hesitate to make changes to gearbox components because of some extra wear and tare.
Just keep in mind that it is radical changes with mega fps and/or super high speed that you can get into trouble with very fast wear and tear on your gearbox and components. Your skill level at teching yout guns is the difference between success and failure when making changes to your gun.

[Brick Stone]

I'll second everything that vanevery posted. Great reply!

To further...

Just increasing the length of the barrel will not increase your FPS per se... That is technically the opposite effect of what a tightbore accomplishes along side of grouping improvement.  Usually any increase you see by doing this alone usually comes from you putting in a new bucking or just resetting and resealing up the one you already had installed. If you replace the barrel.  Replace the bucking too.

Cylinder and barrel length are matched for effectiveness with the placement of the port on the cylinder.   If you increase the length of the barrel too much... you will not gain, rather you will lose FPS.  The BB will have already achieved it's maximum FPS before it leaves the barrel and it will then slow before exit.   However,  Moving from lets say a 407mm to a 433mm is consistent with the port placement.  If it is a tightbore, all the better. You will increase FPS and range as well.  Same holds true with any small incremental increase in barrel length. As in going from a 274mm to a 300mm.   But again only if it is a tight bore barrel.   Small barrel length increases within the same diameter as the original barrel will not give you any noticeable increase unless you implement what I mention throughout this post..

To get your 15 to 20 without any strain on the mechanism do the following.  

Consider a tightbore barrel.  This actually decreases the amount of air in the barrel as it is tighter. Giving it more punch... But it really is just for better groupings.   FPS increases are just a small bonus.  The amount of negative impact on performance is negligible.  

Next.   Consider a different bucking.   But keep in mind that no matter what bucking you use.... Making sure the seal is good is the most important thing.  
In every one of my AEG's I use Teflon tape inside and outside of the bucking with super lube to ensure that my bucking is sealed tightly onto the barrel. Mind you only on the very edge would you apply the lube because you don't want that stuff in the hop up..

Also, I do the barber pole wrap with Teflon tape down the barrel if it is possible.   This increases stability for the inner barrel. BUT only if it actually allows you to re-insert it. If it is too tight... Just use the lube around the outer edge and wipe off whatever gets extruded during reinsertion. The tightbore will give you a 10 fps increase respectively. For the extra 5fps seal up the bucking as I've mentioned.  You see this in DMR builds.   This will possibly give you a 5 to 10 FPS increase as well.  
Again,  The barber pole wrap only works if there is space enough for the inner barrel to fit into the outer once applied.   What it does is keep the inner barrel steady during use so the seal you've created doesn't become compromised by a wobbly inner barrel that has space to move.  Some tightbores like Prometheus, actually have a larger outer diameter than stock barrels.  This makes the Teflon tape mod somewhat difficult if even possible as I have mentioned.  Particularly with the KWA outer barrel. They make their stuff with strict tolerances and a Teflon tape mod works well with their stock barrel but not so well with aftermarket upgrades.

A lighter piston will not give you an increase in FPS.... That would increase RPS but only slightly.  A lighter piston with aluminum head will give it a punch.  But that is what is already used in stock form.

Inner springs will increase your FPS dramatically.  Unless you are prepared to upgrade the reliability aspect of the other parts involved in the mechanical operation it is additional strain on other stock components.  Which you stated you would like to avoid.

Always go for reliability and stability first.  This way your upgrade path will compliment itself along the way... leaps and bounds in particular areas of upgrading will require you to upgrade several other items to again return the reliability of the build.

Edited by Brick Stone, 07 August 2012 - 10:17 AM.

[niko_gpsy]

Brick Stone, on 07 August 2012 - 09:31 AM, said:

I'll second everything that vanevery posted. Great reply!

To further...

Just increasing the length of the barrel will not increase your FPS per se... That is technically the opposite effect of what a tightbore accomplishes along side of grouping improvement.  Usually any increase you see by doing this alone usually comes from you putting in a new bucking or just resetting and resealing up the one you already had installed. If you replace the barrel.  Replace the bucking too.

Cylinder and barrel length are matched for effectiveness with the placement of the port on the cylinder.   If you increase the length of the barrel too much... you will not gain, rather you will lose FPS.  The BB will have already achieved it's maximum FPS before it leaves the barrel and it will then slow before exit.   However,  Moving from lets say a 407mm to a 433mm is consistent with the port placement.  If it is a tightbore, all the better. You will increase FPS and range as well.  Same holds true with any small incremental increase in barrel length. As in going from a 274mm to a 300mm.   But again only if it is a tight bore barrel.   Small barrel length increases within the same diameter as the original barrel will not give you any noticeable increase unless you implement what I mention throughout this post..

To get your 15 to 20 without any strain on the mechanism do the following.  

Consider a tightbore barrel.  This actually decreases the amount of air in the barrel as it is tighter. Giving it more punch... But it really is just for better groupings.   FPS increases are just a small bonus.  The amount of negative impact on performance is negligible.  

Next.   Consider a different bucking.   But keep in mind that no matter what bucking you use.... Making sure the seal is good is the most important thing.  
In every one of my AEG's I use Teflon tape inside and outside of the bucking with super lube to ensure that my bucking is sealed tightly onto the barrel. Mind you only on the very edge would you apply the lube because you don't want that stuff in the hop up..

Also, I do the barber pole wrap with Teflon tape down the barrel if it is possible.   This increases stability for the inner barrel. BUT only if it actually allows you to re-insert it. If it is too tight... Just use the lube around the outer edge and wipe off whatever gets extruded during reinsertion. The tightbore will give you a 10 fps increase respectively. For the extra 5fps seal up the bucking as I've mentioned.  You see this in DMR builds.   This will possibly give you a 5 to 10 FPS increase as well.  
Again,  The barber pole wrap only works if there is space enough for the inner barrel to fit into the outer once applied.   What it does is keep the inner barrel steady during use so the seal you've created doesn't become compromised by a wobbly inner barrel that has space to move.  Some tightbores like Prometheus, actually have a larger outer diameter than stock barrels.  This makes the Teflon tape mod somewhat difficult if even possible as I have mentioned.  Particularly with the KWA outer barrel. They make their stuff with strict tolerances and a Teflon tape mod works well with their stock barrel but not so well with aftermarket upgrades.

A lighter piston will not give you an increase in FPS.... That would increase RPS but only slightly.  A lighter piston with aluminum head will give it a punch.  But that is what is already used in stock form.

Inner springs will increase your FPS dramatically.  Unless you are prepared to upgrade the reliability aspect of the other parts involved in the mechanical operation it is additional strain on other stock components.  Which you stated you would like to avoid.

Always go for reliability and stability first.  This way your upgrade path will compliment itself along the way... leaps and bounds in particular areas of upgrading will require you to upgrade several other items to again return the reliability of the build.

Very well said Brick.

[henryED86]

ohhh

Thanks Brick !!...

...one more question ..... I'm thinking on wrapping Teflon around the stock barrel to give it more stability  and later on the bucking ...any advise on how to do this??? or is this a straight forward Teflon wrapping.