Poor range on SCAR

Flecktarn

Hey again all,

I recently bought myself a AGM Scar around Christmas and was delighted with it bar one thing, the range. The range on the Scar is tbh dismal, I have a field beside my house where the Scar can only get about half across it whereas my ACM P90 can go the full distance of the field.

I cleaned the barrel and tried all different hop-up positions but there very little or no change, do the hop-up need to be broke in or is that a myth?

Cheers guys!

Puding

bucking so have a break in period before the best results are obtained, the number of round can very depending on the type of bucking

it could be that the bucking is too hard if it is stock, there normally aimed at higher fps and if the bucking is to hard at the lower fps it could not be having as much of an effect

do you know what fps the scar is firing at?

Gatling

id recommend putting a Guarder silicon hop up to replace the agm one should give you a lot better range

Flecktarn

Puding wrote: »

bucking so have a break in period before the best results are obtained, the number of round can very depending on the type of bucking

it could be that the bucking is too hard if it is stock, there normally aimed at higher fps and if the bucking is to hard at the lower fps it could not be having as much of an effect

do you know what fps the scar is firing at?

In the box came a chrono test from the retailer and it was 94.45m/s which is about 310 fps?

Gatling wrote: »

id recommend putting a Guarder silicon hop up to replace the agm one should give you a lot better range

Yeah was planning to do that, only the fact is that I'm thinking there might be something wrong with it as its not even a month old.

Puding

Flecktarn wrote: »

In the box came a chrono test from the retailer and it was 94.45m/s which is about 310 fps?

when trying to sort out problems i try and work by a process of elimination, i would get it chronoed first to test fps, just confirming fps is as noted, be aware that opening the aeg up will more than likely void your warranty so if there is a problem best to talk to the retailer first if it is brought inside of Ireland

if it is not a fps problem or anything the retailer can deal with then move onto change bucking as this is easy enough and work from there

Flecktarn

Puding wrote: »

when trying to sort out problems i try and work by a process of elimination, i would get it chronoed first to test fps, just confirming fps is as noted, be aware that opening the aeg up will more than likely void your warranty so if there is a problem best to talk to the retailer first if it is brought inside of Ireland

if it is not a fps problem or anything the retailer can deal with then move onto change bucking as this is easy enough and work from there

Sound I'd be best sending it back to them so, cheers lads!

Gatling

check the air nozzle first

Flecktarn

Gatling wrote: »

check the air nozzle first

Hmm don't really want to open it as I think I'll void the warranty.

mgsguru

you could always take it back to the shop you bought it in and get them to check it over.

Flecktarn

Alright so it appears the hop up bucking on these is sh1t. So I've been looking at the guarder hop ups but the only ones I could find are this one that only comes with the shell should we say and this one for a M16A2?

Would the M16 be ok or does anyone have a link to a different one?

Puding

Flecktarn wrote: »

Alright so it appears the hop up bucking on these is sh1t. So I've been looking at the guarder hop ups but the only ones I could find are this one that only comes with the shell should we say and this one for a M16A2?

Would the M16 be ok or does anyone have a link to a different one?

if your just looking for the bucking then this is all you need http://shop.ehobbyasia.com/guarder-improved-hop-up-bucking-for-aeg-50-hardness.html no need to replace the whole hop up unit

Leftyflip

You needthe rubber, not the chamber. Put one of these in.

Edit: Grrr, Puding beat me to it.

Flecktarn

You sure guys its not just a poor overall hop up and needs to be replaced all together?

Like improve range?

Leftyflip

The hop chamber shouldn't be the problem, it's most likely the bucking, put a Guarder one in and fps and range will improve.

Flecktarn

Leftyflip wrote: »

The hop chamber shouldn't be the problem, it's most likely the bucking, put a Guarder one in and fps and range will improve.

Win! Cheers lads!

DeBurca

You can also get them from Mid West Airsoft, if you like to buy Irish

http://www.mwairsoft.net/index.php/parts-a-springs/283-guarder-hop-bucking

Flecktarn

DeBurca wrote: »

You can also get them from Mid West Airsoft, if you like to buy Irish

http://www.mwairsoft.net/index.php/parts-a-springs/283-guarder-hop-bucking

Darn it, I would have but I just bought them off Ehobby

Flecktarn

Right back again unfortunately, decided to go out plinking today and the range was quite poor tbh, took it apart, reseated the nub and the adjustment arm but still was quite lacking in range. Air nozzle is grand, maybe perhaps a poor seal?

Flecktarn

Anybody?

defenderdude

Flecktarn wrote: »

Anybody?

So did you ever get it chrono'd to confirm the fps?

Like Puding mentioned earlier in the thread - the hopup rubber can take a bit of bedding in before it works to it's best potential. Even at relatively low fps (200-250) you should get a good range (but low velocity) with a guarder rubber so lash a load through it to see if it improves. Is the hopup having an effect?

Did you ask the retailer about it before you opened it yourself?

I'd say if the nozzle is ok and you installed the hopup rubber ok - the airseal is possibly ok.

I think you could be chasing your tail fixing the wrong problem (like I've done in the past) - just good to know for sure the gun is ok, so best to check the fps and it will at least let you know if youre wasting your time messing with the front end or if the gear box needs opening (could be the piston o-ring just needs replacing...)

There are too many potential things to check without first knowing that the gun has the expected power to start with.

Not much use to you I'm afraid but best of luck with it anyway.;)

Flecktarn

defenderdude wrote: »

So did you ever get it chrono'd to confirm the fps?

Like Puding mentioned earlier in the thread - the hopup rubber can take a bit of bedding in before it works to it's best potential. Even at relatively low fps (200-250) you should get a good range (but low velocity) with a guarder rubber so lash a load through it to see if it improves. Is the hopup having an effect?

Did you ask the retailer about it before you opened it yourself?

I'd say if the nozzle is ok and you installed the hopup rubber ok - the airseal is possibly ok.

I think you could be chasing your tail fixing the wrong problem (like I've done in the past) - just good to know for sure the gun is ok, so best to check the fps and it will at least let you know if youre wasting your time messing with the front end or if the gear box needs opening (could be the piston o-ring just needs replacing...)

There are too many potential things to check without first knowing that the gun has the expected power to start with.

Not much use to you I'm afraid but best of luck with it anyway.;)

Cheers Defenderdude, well I did get a sheet with the gun to clarify it was .89 of a joule which is roughly 300fps, but unfortunately I have no chrono . I tried putting up a few layers of cardboard up and having a go with both my M16 and SCAR and they seemed to be par with each other so I think the fps level is reasonable.

Maybe it might just need to break in, so your saying I should put a rake of rounds through it? I don't actually know if its making much of a difference because I received it without a hop up adjustment arm, so I'm not sure!

I did ask the retailer about and they said the rubber is quite poor in the AGM scar so when I went to replace it there was pieces missing in the hop unit so I can't compare them!

MonkeyGuy

Flecktarn wrote: »

Cheers Defenderdude, well I did get a sheet with the gun to clarify it was .89 of a joule which is roughly 300fps, but unfortunately I have no chrono . I tried putting up a few layers of cardboard up and having a go with both my M16 and SCAR and they seemed to be par with each other so I think the fps level is reasonable.

Maybe it might just need to break in, so your saying I should put a rake of rounds through it? I don't actually know if its making much of a difference because I received it without a hop up adjustment arm, so I'm not sure!

I did ask the retailer about and they said the rubber is quite poor in the AGM scar so when I went to replace it there was pieces missing in the hop unit so I can't compare them!

Maybe a new hop up altogether is what you need. I've had a similiar experience with my Dboys SPR. Nothing I tried worked. I know there's been some debate about them, but I got a new bucking with the fishbone spacer (nub) and it works wonders. Although I noticed there is a, for lack of a better word, bump, on the part of the bucking which actually makes contact with the BB, which could be a contributing factor. It's worked for me. If you're not sure about the problem, this is cheaper than a new hop up.

Flecktarn

Right bit of an update:

It appears that the hop up wheel isn't putting enough pressure on the adjustment arm which in turn isn't tuning the hop-up high enough for decent range. The whole design of the hop up seems to be poor.

I presume I should get a completely new hop up chamber like a normal type M4/M16 one but should I expect the retailer to arrange that for me since it was bought faulty and still is?

Cheers guys.

DeBurca

Flecktarn wrote: »

Right bit of an update:

It appears that the hop up wheel isn't putting enough pressure on the adjustment arm which in turn isn't tuning the hop-up high enough for decent range. The whole design of the hop up seems to be poor.

I presume I should get a completely new hop up chamber like a normal type M4/M16 one but should I expect the retailer to arrange that for me since it was bought faulty and still is?

Cheers guys.

Are you sure that the hop-up nub is there, it sits in the adjustment arm and presses on the hop-up bucking
Its the small black piece at the bottom of the hop-up photo

Flecktarn

DeBurca wrote: »

Are you sure that the hop-up nub is there, it sits in the adjustment arm and presses on the hop-up bucking
Its the small black piece at the bottom of the hop-up photo

100% percent, have 3 hop up types here, tried each nub and bucking and still nothing.

DeBurca

Are you able to remove the inner barrel so that you verify that when you adjust the wheel you can see it pushing down on the bucking
This is best seen from the barrel end looking twords the hop-up unit

Flecktarn

DeBurca wrote: »

Are you able to remove the inner barrel so that you verify that when you adjust the wheel you can see it pushing down on the bucking
This is best seen from the barrel end looking twords the hop-up unit

Yeah but it is adjusting the nub very slightly and not to its full potential.

When I physically push down on the adjustment arm I can see the bucking doing its job but the adjustment arm doesn't seem to have the strength to move it enough

DeBurca

Flecktarn wrote: »

Yeah but it is adjusting the nub very slightly and not to its full potential.

When I physically push down on the adjustment arm I can see the bucking doing its job but the adjustment arm doesn't seem to have the strength to move it enough

It sounds as if it is as you say that the arm is not beening fully pushed by the adjustment wheel
As I see it you have 2 choices get a new unit or add some material to the arm where it contacts the adjustment wheel
A new unit is straight forward and it may be worth contacting the retailer from which it was got
If on the other hand if you have to get a new one yourself then you have nothing to loose and why not see if you can fix it yourself by adding a piece yourself to the existing arm so as to put more pressure on the bucking
The best method would probally be a use some epoxy to build up the lip and after it has set file/sand so that you have increased the height by about 2mm
As a quick check you could may be use a few lairs of tape just to see if my method will produce the desired effect
You could also put 3 or 4 layers of taps around the nub and try that as a temp fix
If any of the above work at least it shows that the problem is hop-up related and that the rest is OK and you might even enjoy yourself while doing it
As I said if you are going to replace the hop-up unit then you have nothing to loose trying the above

Flecktarn

DeBurca wrote: »

It sounds as if it is as you say that the arm is not beening fully pushed by the adjustment wheel
As I see it you have 2 choices get a new unit or add some material to the arm where it contacts the adjustment wheel
A new unit is straight forward and it may be worth contacting the retailer from which it was got
If on the other hand if you have to get a new one yourself then you have nothing to loose and why not see if you can fix it yourself by adding a piece yourself to the existing arm so as to put more pressure on the bucking
The best method would probally be a use some epoxy to build up the lip and after it has set file/sand so that you have increased the height by about 2mm
As a quick check you could may be use a few lairs of tape just to see if my method will produce the desired effect
You could also put 3 or 4 layers of taps around the nub and try that as a temp fix
If any of the above work at least it shows that the problem is hop-up related and that the rest is OK and you might even enjoy yourself while doing it
As I said if you are going to replace the hop-up unit then you have nothing to loose trying the above

Cheers DeBurca just a few questions though:

1: Are you saying to add some tape where the arm goes into the adjustment wheel?

2: Regards building up the arm, will I put the tape/epoxy on the groove where the nub fits?

I did indeed cut a nub sized piece of a o-ring that was bigger then a normal sized nub but it didn't seem to make any difference at all.

MonkeyGuy

Flecktarn wrote: »

I did indeed cut a nub sized piece of a o-ring that was bigger then a normal sized nub but it didn't seem to make any difference at all.

Then it must be the arm. Have you tried taking out the bucking and turning the wheel to see if the arm is moving correctly?

Flecktarn

MonkeyGuy wrote: »

Then it must be the arm. Have you tried taking out the bucking and turning the wheel to see if the arm is moving correctly?

Do you mean to remove the bucking and nub and see if the arm moves at all?

MonkeyGuy

Flecktarn wrote: »

Do you mean to remove the bucking and nub and see if the arm moves at all?

Yup. If it moves I don't know what the problem could be but if the arm doesn't move, you know your problem, and I'm sure somebody around here would know how to fix it!

Flecktarn

MonkeyGuy wrote: »

Yup. If it moves I don't know what the problem could be but if the arm doesn't move, you know your problem, and I'm sure somebody around here would know how to fix it!

Will try later, good idea thanks.

DeBurca

Flecktarn wrote: »

Cheers DeBurca just a few questions though:

1: Are you saying to add some tape where the arm goes into the adjustment wheel?

2: Regards building up the arm, will I put the tape/epoxy on the groove where the nub fits?

I did indeed cut a nub sized piece of a o-ring that was bigger then a normal sized nub but it didn't seem to make any difference at all.

The easiest way to check is to put a a few layers of tape into the semicircular groove that the nub fit in
This shoud then push down on the bucking further and is a simple thing to do/undo as a means of testing things
If this produces the desired effect/improves things then you know that your problem is hop-up related
If on the other hand there is little or no effect the maybe your problem is elsewhere, may be an air seal problem
If you are leaking air someplace then your overall FPS will be down and because with the BB having less speed through the hop-up unit then normal the hop-up has less effect (imparts less backspin)
Less backspin means less overall range
If you could Chrono your Scar at least you would know for sure that you have no issues with air seal problems etc

Flecktarn

DeBurca wrote: »

The easiest way to check is to put a a few layers of tape into the semicircular groove that the nub fit in
This shoud then push down on the bucking further and is a simple thing to do/undo as a means of testing things
If this produces the desired effect/improves things then you know that your problem is hop-up related
If on the other hand there is little or no effect the maybe your problem is elsewhere, may be an air seal problem
If you are leaking air someplace then your overall FPS will be down and because with the BB having less speed through the hop-up unit then normal the hop-up has less effect (imparts less backspin)
Less backspin means less overall range
If you could Chrono your Scar at least you would know for sure that you have no issues with air seal problems etc

Thanks, I think I might have found the problem, the adjustment arm seems to be cracked. I've glued it together again and I'm waiting for it to set. I presume this is what was causing the problem.

Flecktarn

Well talk about out of the frying pan into the fire. I wrapped the nub in tape and shoved it down into the bucking and it worked although I'm not using the arm as its banjaxed, I'm getting decent range though.

But the fps rate is definitely down, tried shooting cardboard at point blank and isn't piercing it at all.

Could anyone enlighten me as to what's going on?

DeBurca

Flecktarn wrote: »

Well talk about out of the frying pan into the fire. I wrapped the nub in tape and shoved it down into the bucking and it worked although I'm not using the arm as its banjaxed, I'm getting decent range though.

But the fps rate is definitely down, tried shooting cardboard at point blank and isn't piercing it at all.

Could anyone enlighten me as to what's going on?

The more hop-up you apply the more it reduces your FPS
As the bucking is pushed into the barrel so that it can grip the BB as it passes through it so as to impart backspin to the BB
The effect of back spin is to cause the BB to rise, thereby counteraction the natural tendency of the BB to fall due to gravity
If it is set right the two opposing forces cancel one another out and you get almost level flight from the BB until is looses forward thrust due to air resistance and fall to earth or better still your opponent

Now here is the bad bit, in pushing through the restricted space caused by the nub pushing on the bucking to impart back spin some of the energy imparted by the spring/piston is used just to overcome this obstruction and so there is less energy left to propel the BB down range
Remember that the total maximum energy that we have is 1 joule max
So the more hop-up we use the less FPS
That is why many airsofters use very soft bucking at 1 joule or less because the softer the bucking the sticker it is and can grip the BB and impart backspin easier without the need to intrude into hop-up unit as much as a harder bucking
So if BB can pass through the bucking easier then there is more energy left the propel the BB forward

Flecktarn

DeBurca wrote: »

The more hop-up you apply the more it reduces your FPS
As the bucking is pushed into the barrel so that it can grip the BB as it passes through it so as to impart backspin to the BB
The effect of back spin is to cause the BB to rise, thereby counteraction the natural tendency of the BB to fall due to gravity
If it is set right the two opposing forces cancel one another out and you get almost level flight from the BB until is looses forward thrust due to air resistance and fall to earth or better still your opponent

Now here is the bad bit, in pushing through the restricted space caused by the nub pushing on the bucking to impart back spin some of the energy imparted by the spring/piston is used just to overcome this obstruction and so there is less energy left to propel the BB down range
Remember that the total maximum energy that we have is 1 joule max
So the more hop-up we use the less FPS
That is why many airsofters use very soft bucking at 1 joule or less because the softer the bucking the sticker it is and can grip the BB and impart backspin easier without the need to intrude into hop-up unit as much as a harder bucking
So if BB can pass through the bucking easier then there is more energy left the propel the BB forward

Great piece of reading DeBurca cheers!

I do indeed have my old JG M16 bucking in the Scar at the moment so I presume I should put in the softer Guarder one? And also tune the hop up down a bit?

DeBurca

Flecktarn wrote: »

Great piece of reading DeBurca cheers!

I do indeed have my old JG M16 bucking in the Scar at the moment so I presume I should put in the softer Guarder one? And also tune the hop up down a bit?

A Guarder Silicone Bucking because it is softer/sticker will impart more spin for the same amount of pressure on the hop-up arm
So you can turn it down a wee bit and still achieve the same effect