[1tonne]

Interesting guide. Somethings go against other opinions I have read but always interesting to read another view.

Is it the soft bucking idea that you are unsure of?
Many people do not agree with the idea of soft buckings on a high FPS gun. If done right though, and the person is careful on how much hopup they apply, the gun should be more accurate and the bcking can last a long time. Not as long as a hard bucking but still a very long time. My 55 degree bucking has lasted me about 10,000 shots and it is still going strong.
The less hopup the better because the hopup is pushing the bb downwards. This means that there is 2 different forces. One from the compressed air pushing the bb forward and the other force pushing the bb down. Down and forward do not go well togeather to make it go straight.
Like some of the others have mentioned, I should try the Long Range Barrel mod. This is in effect a form of hopup and it does not apply a downforce. It's mamking the bb travel along the top of the barrel to which in turn creates some back spin.

 

[vindicareassassin]

Like some of the others have mentioned, I should try the Long Range Barrel mod. This is in effect a form of hopup and it does not apply a downforce. It's mamking the bb travel along the top of the barrel to which in turn creates some back spin.

Ah, yeh, no, its not like that in the form that we use it,

It was like that in the 'classic airsoft' guns, where it was a form of hop-up in a stepped hop barrel.

We use it to stabalize and equalize the back spin put on by our hop nubs, so that the BB to BB differences in hop application are minimised, there-by making the shot to shot trajectory, not only, similar but also flatter so that you have less need to 'lob' shots on to target, it should fly the better part of straight there :yup:

You can take it to an extreme and gain usefull hop from an LRB, my 350 fps MOD14 EMR used to over hop a .4 and correctly adjusted I could send it out to the same range I could get a .28, but the flight path was completely unrealistic and impossible to use in-game unless I was stood at the top of a building, shooting down......

The absalute maximum you should be using is 3mm of down curve, and at that point you will be generating hop.....

The norm is between 1 and 2mm of down curve using less on longer barrels and slightly more on short ones, but ultimately it needs to be set from gun to gun as set-ups all differ :tup:

 

[Dorekido]

seem like pretty hard to make M50 usable. thanks for explain more details for me and other members.

 

[1tonne]

Ah, yeh, no, its not like that in the form that we use it,

It was like that in the 'classic airsoft' guns, where it was a form of hop-up in a stepped hop barrel.

We use it to stabalize and equalize the back spin put on by our hop nubs, so that the BB to BB differences in hop application are minimised, there-by making the shot to shot trajectory, not only, similar but also flatter so that you have less need to 'lob' shots on to target, it should fly the better part of straight there :yup:

You can take it to an extreme and gain usefull hop from an LRB, my 350 fps MOD14 EMR used to over hop a .4 and correctly adjusted I could send it out to the same range I could get a .28, but the flight path was completely unrealistic and impossible to use in-game unless I was stood at the top of a building, shooting down......

The absalute maximum you should be using is 3mm of down curve, and at that point you will be generating hop.....

The norm is between 1 and 2mm of down curve using less on longer barrels and slightly more on short ones, but ultimately it needs to be set from gun to gun as set-ups all differ :tup:

Had a read of your thread on the LRB. Good. I should try it.
What do you think is the best way to do it for the VSR. To make it adjustable so it can go back to original?

Once I have perfected it, I will add it to my big long chronicle at the start of this thread.

 

[vindicareassassin]

Had a read of your thread on the LRB. Good. I should try it.
What do you think is the best way to do it for the VSR. To make it adjustable so it can go back to original?

Once I have perfected it, I will add it to my big long chronicle at the start of this thread.

Theres loads of different methods, Cheeseman has worked in conjunction with Hunterseeker5 to produce a wedge, and I use a couple of different methods.

In my case both of my VSRs are Gspecs, 1 has a long inner barrel and 1 is a scout length (minus silencer) on the long I've used 2 different methods, but both were fixed, 1st I used a small length of quite thick ally tube that was threaded to take captured bolts that went through the silencer body that held the barrel at about 1.5mm curve, the method I currently use is a long inner tube that surrounds the inner barrel, this is held in place by a barrel spacer that runs 1/3rd the length of the inner barrel and a wedge at the muzzle end that holds it at about 1.5mm curve.

The scout has a bored out muzzle hole on the outer barrel with a special barrel that runs to the very end of the outer barrel, again using a 1/3rd length barrel spacer at the hop end. The adjustment comes from an M4 bolt that is threaded at the very end of the outer barrel, this can then be adjusted from 0mm to about 4.5mm curve by screwing the bolt in to the required amount, I made a selection of spacers that sit under the barrel, to act as a sort of stop for the barrel muzzle, in 0.5mm thickness'. I'm still perfecting this at the moment as the shorter barrel needs a tad more setting up, but once I've found the sweet spot I'll probably fit a couple of clapping grub screws in place of the spacers situated at 120 degrees to one-another to hold it all in place. I use a similar method to this in my M14 Scout aswell.

The other method I use is on the DE M50, again starting witha 1/3rd length barrel spacer at the hop end, I filed the outer barrel muzzle into an oval, so that the BB doesn't hit it on the way out, I then drilled a hole in the outer barrel that a bolt goes through, this bolt screws into a thick ally sleeve that holds the end of the barrel, when you tighten the bolt, the sleeve, and inner barrel, are pulled down following the oval muzzle hole, if you make the bolt the right length this will lock against the inner barrel and act as a stop to prevent it bouncing around to much and hold the downward curve, and the inner barrel itself acts like a spring to hold the bolt tight in place, once I'd set this up I just glued the bolt head to the outer barrel and now nothings going nowhere.:tup:

It realy is just a matter of what you want to achieve vs whether form over function matters to you vs the engineering skill involved to get the job achieved with the minimum amount of fuss and parts :shrug:

I have found that the wall thickness on outer barrels is thick enough to support a thread and screw/bolt, but it doesn't take much for it to strip so not realy up to constant use, I try when ever posible to reinforce with a matching bolt where and when ever possible, though sometimes it can look down right ugly :shrug:

 

[Lightbulb]

Yes the bucking thing is one difference. The other differences are highlighted below. This is a great guide by the way not seen some of those things done before. Certainly a good guide for a newbie.

I then tested the gun and it only fired at about 470fps. I knew I could get more out of the gun so I got a new o-ring (Sorry, I cannot remember the size it was).

Cylinder o-ring I assume?

NYLON CYLINDER GUIDES

I hadn't heard of this before. Will have to give it a go.

Airbreak; To be or not to be

On many websites it mentions to cut the airbrake off and you will gain about 60fps. This is wrong.[/QUOTE]

This is the biggest difference from common consensus I have seen.

If you increase the cylinder volume there is more air blowing the bb out the barrel. I cannot see why this would not increase fps - maybe with a light bb it will exit the barrel before all the air has exited, but with a heavier bb I believe the bigger volume will result in more power. I have never tested it (I need to get a chrono) but it doesn't seem right - and clearly a lot of people have reported buying Bar 10's and increased the fps by cutting it off.

BUCKING MODS AND AIR SEAL

To do this I got a 55 degree bucking (Soft bucking) and installed it. [/QUOTE]

This does go against what some people say, but other agree with you, no need to debate people just need to try it and see what works best for them.

Making it quiet

A lot of people also fill the voids in the rifle to stop it echoing - clay, exanding foam or sound insultating foam are popular.

If they are not matched right then the excess air pushes the cracking sound from the piston slamming into the cylinder head, out the end of the barrel. If the barrel is the perfect length for the cylinder, then most of that noise will be trapped in your barrel. This Mod can also increase your FPS dramatically.

Do you think this is dependant on the weight of bb used? Heavier bb's seem to gain more energy in short barrels - I think this is because the light bb will exit the barrel before all the air has existed - leading to the crack.

cylinder to barrel ratio of 2.417:1. (I read on the net that this ratio works so this is where I started experimenting with inner barrels and then I wanted to refine it even more to get the perfect barrel for the cylinder)

I have read other ratio's - 1:2 for example.

When I installed the 500mm barrel there was a big increase in FPS from 525fps to 570-580fps. This is too high for our club and so I downgraded it with an M150 spring. Accuracy was brilliant and it was quiet.

That's with 0.2's I assume? What was the barrel length before, stock presumably? I touched on this above. I wonder if it was shooting at over 3J before but the 0.2 was existing the barrel before all the air existing - meaning if you have used 0.4's in the old barrel you still would have got around 3J?

That must be very good compression with a m170 - just goes to show m190's really are overkill.

If you do use a silencer, then before mounting it, pull it apart and check that there are no stray hairs or lose bits on the foam that may cause inaccuracies. Also, if any of the foam is deformed then put these deformed parts closer to the barrel. So the closer to the exit should have the best bits of foam.

Generally better to use a lined silencer like on a VSR - a plastic tube in the middle. I had a friend with a foam silencer with a highish ROF aeg and it chewed up the foam wrecking the accuracy - obviously not such an issue with an BASR and you are not turning the rifle and shooting at the same time - normally.

So use a 550mm x 6.03mm inner barrel if you want the best length.[/

QUOTE]

Most people seem to say a bit shorter than this is best but there are so many variables its hard to know. I just read Cheeseman saying he can get 100m range from a <200mm barrel so maybe there isn't a 'best'.

VSR-10 AEG BARREL MOD

Not seen this before, good to know.

To purchase a PDI Variable Hopup Chamber or Not.[/quote]

Different reason not to bother but the same conclusion. A lot of people say two hop arms are a pain to adjust. TDC seems superior to me.

BB Brands

Well, to get the very best results, you most likely do have to pay the earth and get really expensive bb's but in my experience I do not think that the cost is worth it. The improvement is minimal.

Some people say that the benefits of 0.4's over lighter bb's out weigh the generally higher chance of air bubbles. I have not done enough testing to comment myself.

Here is a rough guideline as to which bb to use. Sometimes you may want to use slightly heavier so the wind does not affect as much.

Seems lower than others recommend. I don't think there is any reason not to use heavier bb's in 1J aeg's except cost. I know people recommend using 0.3's in fairly lower powered dmr's.

----

Thanks again for a great guide - and to vindicareassassin for expanding on the LRB a but more. I really need to move somewhere with a garden so I can test all this stuff.

 

[1tonne]

1. The oring that I changed to get better FPS/compression was just the piston O-ring

2. The VSR already has a cylinder that is way to big for the stanard barrel. By taking off the airbreak you are just increasing the cylinder volume. This will increase the waist air that comes out the end of the barrel once the bb has left. So it will most likely increase the volume of the cracking sound.
If you increase the barrel length, then you can cut the airbreak and it can help increase the FPS. Especially if you can match the right cylinder to barrel volumes.

3. 55 degree bucking does work but you just need to be careful. I have even seen it somewhere else on this site. Check under the heading of "Buckings" about halfway down the page: http://www.airsoftsniperforum.com/showthread.php?t=684

4. Filling voids is popular and does work but I would rather keep the gun light. You will most likely find that if you match the cylinder and barrel ratios that this will be better than making your gun heavy. My gun is realy, really quiet. (Need to make sure you have a good foam dampening system too.

5. Trying to match the correct Cylinder to Barrel volumes can also depend on the weight of the bb's but I have found that with my gun I can use anywhere between 0.25gm to 0.36gm and there is not much differnece in sound.
There are a lot of ratios out there that people have tried and may work for them. I have found (in my opinion) that the best length barrel for a standard cylinder is a 550mm barrel. This is a ratio of 2.147. I would not risk a ratio of 2:1 (cylinder:barrel). This would mean you would need a barrel of 580mm long. This will not work as I have tried it. I have used a number of different barrel lengths and 550mm seemed best.
Feel free to try it though as I would be interested in your results.

6. The increase from 525 to 570-580fps was with 0.2gm bb's. The original barrle length was 430mm.
It was very good compression. I have pulled apart my VSR10's a lot and I have only ever been about to get perfect compression like that a few times. (Next time I get such good compression, I am not going to pull it apart so quickly)

7. I would think that foam is better in an silencer than having a plastic lining that has holes. I would think that foam would absorb more sound.

8. AEG barrel mod is good. Real good.

9. 0.4gm bb's may outweight the problem with airbubbles but with a 500fps gun the bb's start to lob more. I normally sight my gun in at my rifle range down the back of my propperty which is 50m's long. I found that with 0.36gm bb's, the flight path was more arking. With 0.3gm the bb's are flying near straight to the target.
If you sight a 0.4gm bb onto a target at 50m's it will be more accurate at 50m's compared to a 0.3gm bb. This is because it is not affected by wind and airbubbles so much. So it will travel along the same path (an ark) each time better than the lighter bb. But at other ranges the 0.3gm bb should be more accurate as the bb travels in a straighter line. Not so much of an ark.

 

[vindicareassassin]

1. The oring that I changed to get better FPS/compression was just the piston O-ring

2. The VSR already has a cylinder that is way to big for the stanard barrel. By taking off the airbreak you are just increasing the cylinder volume. This will increase the waist air that comes out the end of the barrel once the bb has left. So it will most likely increase the volume of the cracking sound.
If you increase the barrel length, then you can cut the airbreak and it can help increase the FPS. Especially if you can match the right cylinder to barrel volumes.

3. 55 degree bucking does work but you just need to be careful. I have even seen it somewhere else on this site. Check under the heading of "Buckings" about halfway down the page: http://www.airsoftsniperforum.com/showthread.php?t=684

4. Filling voids is popular and does work but I would rather keep the gun light. You will most likely find that if you match the cylinder and barrel ratios that this will be better than making your gun heavy. My gun is realy, really quiet. (Need to make sure you have a good foam dampening system too.

5. Trying to match the correct Cylinder to Barrel volumes can also depend on the weight of the bb's but I have found that with my gun I can use anywhere between 0.25gm to 0.36gm and there is not much differnece in sound.
There are a lot of ratios out there that people have tried and may work for them. I have found (in my opinion) that the best length barrel for a standard cylinder is a 550mm barrel. This is a ratio of 2.147. I would not risk a ratio of 2:1 (cylinder:barrel). This would mean you would need a barrel of 580mm long. This will not work as I have tried it. I have used a number of different barrel lengths and 550mm seemed best.
Feel free to try it though as I would be interested in your results.

6. The increase from 525 to 570-580fps was with 0.2gm bb's. The original barrle length was 430mm.
It was very good compression. I have pulled apart my VSR10's a lot and I have only ever been about to get perfect compression like that a few times. (Next time I get such good compression, I am not going to pull it apart so quickly)

7. I would think that foam is better in an silencer than having a plastic lining that has holes. I would think that foam would absorb more sound.

8. AEG barrel mod is good. Real good.

9. 0.4gm bb's may outweight the problem with airbubbles but with a 500fps gun the bb's start to lob more. I normally sight my gun in at my rifle range down the back of my propperty which is 50m's long. I found that with 0.36gm bb's, the flight path was more arking. With 0.3gm the bb's are flying near straight to the target.
If you sight a 0.4gm bb onto a target at 50m's it will be more accurate at 50m's compared to a 0.3gm bb. This is because it is not affected by wind and airbubbles so much. So it will travel along the same path (an ark) each time better than the lighter bb. But at other ranges the 0.3gm bb should be more accurate as the bb travels in a straighter line. Not so much of an ark.

1/ This is what we have found, and there is a hell of a lot of difference between manufacturers aswell, a few years back there was a rage about X rings, but after alot of head to head testing we found that there realy wasn't any advantage, depending on what you were looking for, the consesus was an X ring gave more consistency but dragged the fps down due to the extra drag of what was effectively a double O ring :shrug:

2/ Agreed, the cylinder is way to big for the stock barrel, and as Noobie proved in his musings about his BAR-10s, though he approached it from the 'other end' of the thinking by making sure the BB was still in the barrel when the piston hit home.

What needs to be remembered about airbrakes though is.... as soon as you do any porting work to the cylinder head the airbrake is there purely as a volume filler so might aswell be left on to maximise air pushed out the barrel :yup:

3/ This is why I'm doing current testing on the 'J' hop, if you use bathroom grade silicon sealant and a hard rubber you get the best of both worlds.... in theory.... as the silicon is very soft, yet very wear restant ant very stable at the pressures we demand of it, and combined with a hard rubber to maximise sealing at the nozzle you ''should'' end up with the perfect hop.... ish :shrug: The execution of said hop is quite easy, its the getting it right that is the real ball ache, and as I said testing continues as so far results have been impressive but not ideal as yet :shrug:

4/ I always try to fill the voids on my stock with either resin or 2 pack filler as I like the dead feel to the stock when the gun is fired, I can understand the 'keep it light' theory, but I'm a hairy arsed builder during the working week, so weight for me isn't realy an issue unless its my MOD14 then even I have reservations :doh:

5/ I think alot of it is to do with actual individual set up, I mean, My long VSR is quiet, but that has a suppressor fitted, my mates on the other hand runs a 550mm barrel to the end of a PDI barrel, that also runs a bore-up cylinder, with only an Oring glued to the cylinder head as a buffer and, if anything, is a tad quieter than mine :nuts: we both use the same .3 ammo, and are both running at just over 500fps :shrug:

6/ some times its better to follow the 'if it aint broke, don't fix it' philosophy >

7/ Actualy the foam and baffel method, with the baffels set at varying distances, breaks up and re-directs the sound wave more effectively than foam alone, as it re-directs the sound back towards the gun and into the foam, while also reducing the sound wave oscilation by forcing it through a smaller hole, rather than relying on the foam alone to adsorb any sound waves that happen to be flying by :shrug: also the more open grained the foam is the better :tup:

8/ Agreed. Its how I got shot of that piece of crap ally barrel out of the DE M50 :yup: but I span mine up in a drill and used a dremel and filr to re-apply the sealing groove in the right place, then just used floss to hold it in place and seal it.

9/ Mate, you realy need to try an LRB out, your gona love it for the flatter flight trajectory it gives :tup: Both me and my mate use .3s exclusively in our BASRs, we tried .4s but here in the UK the light and back ground colours play tricks on the tan colour and you might aswell be using black BBs, Ive only ever found 1 site here that you can see them for over 75% of the shots fired :shrug: Someone realy needs to invent a white .4 or even .36 again if you ask me

 

[1tonne]

7. I thought that Lightbulb was meaning the silnecer had a plastic lining like the SD6 silencers. I agree with the baffel idea. The G-Spec silencer has baffels too.

9. Will Try it out. Sounds like my cup of tea. Just need to find a little time to get it done.

 

[Lightbulb]

7 - I meant a plastic tube with holes in it like the GSPEC - you can still put foam in there. That would seem the best of both worlds to me. I really need to test some of this stuff.

Still a good thread for discussion though.

 

[1tonne]

So I have just done a basic diagrame (Not scientific) about the tragectory of a LRB.
Is this pretty much right?
So it requires more hopup which can create more inconsistancies but you can get longer range?

 

[Masterjuggler98]

Simple answer: No.

What the LRB does is stabilize the backspin by forcing the bb to the top of the barrel as it exits, so the bb basically rides along the top. This stabilized backspin the allows the bb to maintain it's straight trajectory for a longer period of time. You want to get as straight a trajectory as possible.

Just a little physics lesson: The hopup causes the bb to vibrate in the air, thus putting the center of rotation off the bb's center of mass. This vibration causes the bb to become unstable, and makes the backspin slow down faster. The r-hop applies the backspin at a much slower rate than a bucking, so the bb is much more stable. The LRB has the same effect.

EDIT: By the way, the TDC mod isn't only used for getting the hop straight. It also allows you to apply much more pressure than with the regular adjusters, and it allows you to access the adjuster more easily. It can also hold its place for a much longer period of time than a slider or wheel adjuster will.

 

[1tonne]

I remember seeing a clip on youtube a few years back (Not there not unfortunitly but I am sure others saw it too) where the fired a bb through a glass barrel. When the replay was shown in slow motion, it showed the the bb was already traveling along the top of the barrel. So the only reason I can see for a curved inner barrel is to counter the fact that someone wants to use a lot of extra hopup for a heavier bb. This is pretty much what the Green line in the diagrame is.

In saying this, I will still try the LRB but I would like to make sure it is not just a theory that everybody has run with just because a few people said it worked. (Seems to happen a lot in airsoft)

 

[Masterjuggler98]

I have heard of this glass barrel experiment but the way I heard it was they found the bb to be bouncing around. If you got this info first hand though then I can't really argue with that. What I can say though s the LRB does give a flatter trajectory, when tuned properly. There is an LRB guide in the general section. Start by bending it 2m (measure it, don't estimate) and move it around a little bit, bringing it down to 1 1/2mm then close to 3mm. If it isn't tuned properly you will still see good reslts but they won't be AS good.

Maybe the difference between the LRB and the bb ridng the top in an unbent barrel is like the difference between pressing lightly on a file and really digging it into the wood. I'm still fairly certain the bb does not ride the top in an unbent barrel though.

@Vindi- I didnt realize anyone was still doing testing with the j-hop. Tell us how it turns out.

 

[1tonne]

I have heard of this glass barrel experiment but the way I heard it was they found the bb to be bouncing around. If you got this info first hand though then I can't really argue with that.

I can't say for certain becuase it was so long ago. Tried to find the youtube link to confirm but it's not there anymore.
I guess the only thing left to do is try the LRB.
Will get it done and update you later.

 

[MiloXC3]

I too saw that! It's been removed, though.

 

[vindicareassassin]

The video was removed not long after it was posted by the original postee, lord knows why, perhaps because it would be a HUGE slap in the face for all the nay sayers when physical evidence is produced to back up the opposite theory :shrug:

@Vindi- I didnt realize anyone was still doing testing with the j-hop. Tell us how it turns out.

Yup, so far its been hit and miss, the largest issue is I mostly use 6.03 and 6.08 barrels and finding something as a spacer to fill the barrel window up against is nil, so I'm trying different methods from spacers on a 6mm tube to sticking tape in the window as a packer prior to filling.

So far the results are from over hop to over hop by a country mile, but I think this is due to seepage around whatever I use as an infill.

I have had 1 success though, in my scout M14, testing revealed in semi, firing single aimed shots the flight path was consistent, flick it to full auto and the shots spread a little at 2/3rds distance.

I put this down to the silicon sealant I am using was not forming back as fast as rubber would, causing the variation in shots.

This is strangely ideal for the intended purpose of the weapon, as I use it for recon work where single aim shots need to be accurate, but when the brown stuff hits the spinny thing a blast on full auto is less like a lazer beam that the full auto queens seem aspire too, and more like a suppressive blat, enough for me to get their faces in the dirt for me to di-di anyway :shrug:

 

[1tonne]

One thing I forgot to ask, can the LRB be done successfully with a stainless steel barrel? Wouldn't a stainless barrel be too hard to bend?

 

[vindicareassassin]

It would be 'harder' to bend and hold in the bend, as opposed to using a brass or coated ally barrel

 

[Masterjuggler98]

The same goes for bull barrels. They will hold their bend after a little while and just be harder to bend in the first place. If you use a wedge or a set screw bending it a few mm isn't that hard in the first place though.