67 replies to this topic

[cbono2000]

I have an SR5 that I bought 2nd hand from my brother in law.  I went to AOW III this weeken (regional game in the southeast). I had my gun chrono'd. It only hit 272-273 through several attempts.

Being 2nd hand, I can't be sure what has been done to the gun. Although, he said he had a high torque motor and new buckings.

This seems exceptionally low to me.  Am I off base here? Does that seem right?  Assuming its low as I believe, what can I/should I do to get this up to somewhere in the mid or upper 300s?

Thanks in advance for your help and suggestions!

[ga mercs]

was the hop up off? spring could be weak ... a madbull or systema m110 will get you around 420 fps with 20g

[kwaispro727]

When was the last time he used the gun?  He may have just left the spring compressed.

[cbono2000]

He used the gun frequently, but it was out of commission for a little while with a busted piston. The piston was replaced with a new KWA 'enhanced' piston.

[gcw360]

cbono2000, on 29 April 2012 - 04:17 PM, said:

I have an SR5 that I bought 2nd hand from my brother in law.  I went to AOW III this weeken (regional game in the southeast). I had my gun chrono'd. It only hit 272-273 through several attempts.

Being 2nd hand, I can't be sure what has been done to the gun. Although, he said he had a high torque motor and new buckings.

This seems exceptionally low to me.  Am I off base here? Does that seem right?  Assuming its low as I believe, what can I/should I do to get this up to somewhere in the mid or upper 300s?

Thanks in advance for your help and suggestions!

The SR 5 typically will run between 330 and 360 (subtract about 35 FPS for .25 g bb's) depending on a couple of things.  First, open the upper receiver and determine if you have the type 0.5 cylinder with the port about 1/8" from the back of the cylinder or the type 1 cylinder with the port further forward.  The type 0.5 came on the early (low serial number) SR5's and the type 1 came later.  The type 0.5 will lower the FPS with the SR5 length barrel whereas the type 1 should increase it.

Next, the spring could have been compressed which would reduce FPS.  More likely though, the o-ring needs a stretch assuming the gun hasn't been modified.

Modifications can lead to loss of compression so I would ask you Bro-in-law what he, or a tech, might have done to the gun.

Lastly, a bucking that is damaged or has a poor fit can cause a lose in compression and therefore a lose in FPS.  Is the bucking a stock 2G bucking?  If the bucking is not a KWA 2G that may actually be the culprit.

Also, why did he change the motor?  A stock SR5 motor with a good LiPo will give you over 23 RPS or even as much as 25 RPS.  If that is not the case ask him for the stock motor and reinstall it.

[cbono2000]

gcw360, on 29 April 2012 - 05:35 PM, said:

The SR 5 typically will run between 330 and 360 (subtract about 35 FPS for .25 g bb's) depending on a couple of things.  First, open the upper receiver and determine if you have the type 0.5 cylinder with the port about 1/8" from the back of the cylinder or the type 1 cylinder with the port further forward.  The type 0.5 came on the early (low serial number) SR5's and the type 1 came later.  The type 0.5 will lower the FPS with the SR5 length barrel whereas the type 1 should increase it.

Next, the spring could have been compressed which would reduce FPS.  More likely though, the o-ring needs a stretch assuming the gun hasn't been modified.

Modifications can lead to loss of compression so I would ask you Bro-in-law what he, or a tech, might have done to the gun.

Lastly, a bucking that is damaged or has a poor fit can cause a lose in compression and therefore a lose in FPS.  Is the bucking a stock 2G bucking?  If the bucking is not a KWA 2G that may actually be the culprit.

Also, why did he change the motor?  A stock SR5 motor with a good LiPo will give you over 23 RPS or even as much as 25 RPS.  If that is not the case ask him for the stock motor and reinstall it.

Yeah... i'm not really sure why the motor was replaced.  But I know he doesn't have it... so let's assume for this discussion that the motor broke for some reason and had to be replaced.

As far as the type 0.5 vs 1... here's a link to the open gun if that helps...  https://picasaweb.go...feat=directlink

I'm sorry I'm sort of ignorant as to what all has been done to this gun... I know that makes this more difficult, if not impossible, to troubleshoot.

I really appreciate any info/suggestions you can provide.

Thanks!

[ga mercs]

to see the cylinder pull the back pin and open the gun to see what type of cylinder you have

Edited by ga mercs, 30 April 2012 - 08:04 AM.

[cbono2000]

ga mercs, on 30 April 2012 - 08:02 AM, said:

to see the cylinder pull the back pin and open the gun to see what type of cylinder you have

Here you go...
https://picasaweb.go...feat=directlink

[gcw360]

That's a type one.  Look to the bucking and o-ring for the solution.

[cbono2000]

gcw360, on 30 April 2012 - 11:49 AM, said:

That's a type one.  Look to the bucking and o-ring for the solution.

Should I just buy a new bucking and O-Ring?  Are you saying that should help?

Thanks a lot to you and everyone else who has replied.

[gcw360]

Start with the bucking and nub.  Refresh my memory, this is a stock barrel yes?

[cbono2000]

gcw360, on 30 April 2012 - 12:04 PM, said:

Start with the bucking and nub.  Refresh my memory, this is a stock barrel yes?

Yes, stock barrel.

[superfrog]

Then the fps is about right for a settled spring in a sr5.  they settle around 300 fps after a while.  add .25s and you lose about 30 fps. which is about 270 ish.  About right for either the sr5 or sr7 with settled spring and having been used for 2 years.

[cbono2000]

superfrog, on 30 April 2012 - 01:07 PM, said:

Then the fps is about right for a settled spring in a sr5.  they settle around 300 fps after a while.  add .25s and you lose about 30 fps. which is about 270 ish.  About right for either the sr5 or sr7 with settled spring and having been used for 2 years.

OK... well good to know that it's perhaps in the right ballpark...

Sooooo.... what can I do to boost the fps closer to 325-350 with .25s?

Thanks!

[niko_gpsy]

A settled KWA M120 will get you around 350fps with .25.

[cbono2000]

The pro shop is out of M120 springs... will a Guarder SP120 be the same quality and effect on fps?

As a note... i'm not some kid who's trying to have a d*** measuring contest about FPS... I would just like to get the gun shooting a little hotter given my experience this past weekend in a battle.

Thanks!

[gcw360]

A Guarder SP 120 will shoot hotter than the KWA m120.  I'm guessing a Guarder Sp100 would be more in the ball park.

[niko_gpsy]

A guarder SP110 will get you around 400fps when new.

[gcw360]

That's why I suggested the SP100...approx 365 ish...Oh, crap he he wants FPS with .25's...never mind.

[superfrog]

my sr7 with madbull sp110 is 415 with .2s