[2ndranger]

Hey guys,

I’ve been lurking on this forum for a while reading and learning before I built my first vsr10. The issue I’m having is as follows, when I swapped in a WASP piston/rapax hulk/silverback Teflon spring guide. This combo dropped my rifle from 3.6J to 2.88J. My rifle is a full MLC338 with an AA red chamber, Masada CNC arm and a 240mm 6.00mm stainless tight bore and 70 degree X range bucking.

The original set up that gave me 3.6J was a full Maple Leaf set up: Piston/M165 spring/spring guide. It had been weighted with solder to weigh 100g.

No matter how much I play around with the WASP weight sleeves and air brake/no air brake the velocity stays lower. It’s very consistent but just low. The piston is way quieter than the maple leaf piston. I have cleaned my cylinder of the grease and used a light coating of silicon oil like I read in this forum and it doesn’t seem to help my situation.

Another strange issue is with the maple leaf piston set up the gun doesn’t pass any of the airtight seal test. Finger over nozzle and finger over barrel the air leaks out but chronos a consistent 402fps +\- 3fps with .48g.

The wasp set up seals phenomenal. It will hold the piston back as long as I can hold my finger over the nozzle or barrel.

I’ve very confused and would like to use the wasp and hulk spring since it’s quieter and easier to pull than the maple leaf but the velocity is necessary where I play. DMR’s are allowed 3 joules so snipers really need the extra 0.64J they are allowed.

Thanks for the help guys and sorry for any formatting issues as I am on mobile.

 

[SiliconeSword]

I think that what could be going on is either poor seal, or too much friction.

One thing that SM may not have accounted for is higher power builds, with him never surpassing 2.7J. I feel that maybe the added power of the spring you have is expanding the cup piston head too much and it's creating lots of friction against the walls of your cylinder.
Unfortunately, not much to do about this unless using some Tamiya CeraGrease will sort it out, as this is a disadvantage I think cup pistons may have. I am not super experienced with springers, I actually hate them, but this seems to be the most obvious option.

A friend of mine has tried a number of pistons, and the one that gave the highest power (weighted optimally?) was a Laylax, which is pretty much the same as half the pistons out there. The likely edge the Laylax had was the right size O-ring, other than that, I can't think of a difference. Comparatively, cup pistons tend to have lower power it seems, especially with high power springs, it seems.

 

[Sodium]

I think that what could be going on is either poor seal, or too much friction.

One thing that SM may not have accounted for is higher power builds, with him never surpassing 2.7J. I feel that maybe the added power of the spring you have is expanding the cup piston head too much and it's creating lots of friction against the walls of your cylinder.
Unfortunately, not much to do about this unless using some Tamiya CeraGrease will sort it out, as this is a disadvantage I think cup pistons may have. I am not super experienced with springers, I actually hate them, but this seems to be the most obvious option.

A friend of mine has tried a number of pistons, and the one that gave the highest power (weighted optimally?) was a Laylax, which is pretty much the same as half the pistons out there. The likely edge the Laylax had was the right size O-ring, other than that, I can't think of a difference. Comparatively, cup pistons tend to have lower power it seems, especially with high power springs, it seems.

hehe as the friend who's achieved the best results with the laylax piston, I believe it's down to an ideal o-ring, as well as the teflon guide rings it features. I've not really tried many true cup pistons though, only the SAP and Masada's piston. I've also only ever had my rifle set for about 3.2 joules.

 

[2ndranger]

Siliconsword I will try some tamiya ceraGrease I have laying around to see how that effects the joule output.

I was thinking it could be extreme friction causing the fps drop compared to the oring maple leaf piston. Hand cycling the WASP with the cylinder out and gutted I can feel the friction when i slide it forward.

which Laylax piston are y’all talking about? The Orange one? I see it on brill armory but it says something about it not being fit for high joules? If this is the piston that people are having success with I shall buy it now. I’m a little disappointed with the WASP if it truly can’t do well with high joule builds.

Thanks for the quick replies! If anyone else has any advice I’ll be glad to listen.

 

[SiliconeSword]

Well there's friction when not firing, which could be either the cup or the glide rings.
Try removing the glide rings if possible to try and narrow it down.

The second thing which I already mentioned is the cup expanding when you fire, and pushing the sides against the cylinder a lot harder. This would mean great air seal, but also bad FPS like what you're getting.
If the grease helps a bit, I bet it's that, if not, idk.

The orange one is in fact the correct one, and should be more than adequate for any power level. You will need to weight it, but some solder or lead golf tape and large diameter heat shrink will solve that.
Imo weighted pistons are dumb, as you pretty much want the shortest piston your gun can run without needing spacers (boosts cylinder volume), and there will only be one weight that works well for your exact gun.
What you want to do, is set your hop to the BBs you use, and weight the piston to like 90g, then take off weight until you get the highest power with your desired hop setting and BBs.
For people running barrels shorter than 370mm with .48g BBs in a VSR or SRS, I don't take them seriously when they talk about piston weights and air brakes, as it really makes the most sense to balance everything perfectly with the weakest spring possible.

 

[2ndranger]

This rifle was built to serve one purpose only and that was to fold and fit into a map pack. With the maple leaf S2 chassis and the maple leaf 150mm outer barrel it does that. However I had to switch out the inner barrel from 150mm to 220mm to get the extra velocity I needed.

It was pretty funny though that with .20g and .48g it shot the same fps. 360fps.

After reading you mention short pistons I measured both the WASP and the maple leaf piston. The maple leaf is a good 1.5in shorter so that could also attribute to the velocity difference? I think I shall still purchase a Laylax orange. Or would a springer custom be better? I saw those mentioned as well when I was searching for answers to my WASP issue.

 

[Sodium]

I like the laylax more than the SCW. I find the front guide o-ring and length on the SCW to slow it down some. There's also more space on the laylax to add weight. I have mine weighted to 60g, which seems about perfect for .48g bbs.

On high fps builds, make sure you have some sort of sorbo in your rifle. Personally I really like the laylax sorbos as well. They're just so easy to use. You should also leave the airbrake on and at full length for such a short barrel.

 

[Masada]

Not sure if I missed it, but did you try the WASP setup with the maple leaf spring as well? Also are you using the air brake on the WASP?

 

[2ndranger]

Not sure if I missed it, but did you try the WASP setup with the maple leaf spring as well? Also are you using the air brake on the WASP?

Masada,

Yes, when I installed the maple leaf spring with the WASP output went down by 30fps. Also I have tested both with air brake and without air brake. With the air brake I was only able to get 1.9J. Without the air brake I was getting 2.88J. Which blows my mind because the barrel is so short I would have thought the bb would have left by the time the brake was being engaged. This is obviously a massively overvolumed system.

Sodium, so I can just ignore the “remove the air brake and rubber damper if using higher than SP120 spring with the Laylax piston” warning they have in the description? My cylinder head has a nice thick piece of sorbo on it already. I was too scared to even try letting the aluminum maple leaf piston head smack the steel cylinder head without some padding.

 

[Sodium]

Masada,

Yes, when I installed the maple leaf spring with the WASP output went down by 30fps. Also I have tested both with air brake and without air brake. With the air brake I was only able to get 1.9J. Without the air brake I was getting 2.88J. Which blows my mind because the barrel is so short I would have thought the bb would have left by the time the brake was being engaged. This is obviously a massively overvolumed system.

Sodium, so I can just ignore the “remove the air brake and rubber damper if using higher than SP120 spring with the Laylax piston” warning they have in the description? My cylinder head has a nice thick piece of sorbo on it already. I was too scared to even try letting the aluminum maple leaf piston head smack the steel cylinder head without some padding.

Suprised with the airbrake. Try cutting it down by half (or until fps stops changing) That might reduce the slap while keeping fps just as high.

You have to remove the rubber damper as it'll likely just fall off, the airbrake will be fine though.