Question about velocity

[TheMacGruber]

My question is about tank pressure vs springs.

I currently have a long hk turbine that is giving pressure just over 700. With the stock silver spring I was having no trouble getting velocity in my basement until I tried playing winter ball this last weekend then I had to crank it all the way to the limit.

My experience is that 700 seems to be the sweet spot where the silver spring isn't always enough and the red is way too much. I know phantoms like higher pressure as well but I'd also like to stop taking my favorite gun apart to switch springs so much. Ive noticed every time I break the gun down I get inconsistent velocity for about 100 shots and then it gets consistent.

Ive been debating lowering my tank velocity down to 650 or even 600 and seeing if that takes enough spice to let the red spring be manageable. I'm not sure if that would be too low though.

Has anyone had similar experiences, what were the solutions?

[Jonnydread]

Could you shim the tank to get closer to 800? I have found that my Phantoms really preferred 8-850 vs. 7-750 with stock silver springs.

[TheMacGruber]

No unfortunately not for my tank reg. That's why im looking at lowering it a small amount and throwing the red spring in. Ive honestly considered throwing an HPR on it and testing pressures until I find a sweet spot for the red spring. I'm mostly hoping that someone else did the science already.

I'm hoping that I can fine a sweet spot like tuning a cocker.

[Fossilhead]

Well, way back when I had a PPS phantom stabilizer I ran mine around 600 and I drilled out the face of the tpc.

I do not remember the spring combo. But I know it wasn't stock.

[Pyrate Jim]

In the FWIW dept.
Back when I was young enough to play year-round, I would swap the power tube in cold weather.
PPS makes them (or did) in different sizes. In warm weather, I'd use a #4 with two ports. Winter I'd use a #6 with three ports.
Still may have a couple of both, but I'd have to dig them out and get macro pics of the difference.

It's not as critical as input or springs, but it's an effective option that does make a difference in my experience.

[Jonnydread]

Ancient wisdom!

[flyweightnate]

10 fps per "number" is what I always heard - so a #6 gets you 20 over a #4.

Modern Phantoms are at least a #6, I'd wager - very high flow compared to most Nelson tubes.

[Pyrate Jim]

Ha! You want ancient wisdom, here's a tidbit. A Phantom does not wear out ~ It wears in.
CCI tolerances are tight. From the box they have inherent "pinch Points" that smooth out with use, eventually becoming smooth as butter.
Every time you start swapping out internals, you start that process all over again.

[Chuck E Ducky]

Stock Silver springs sweet spot at 800-850psi depending on how broken in your marker is and setup.

If you are getting velocity swings it’s likely due to paint. If it’s not paint then it’s because your TPC is adjusted outside of its max range and bouncing around.

You could change springs out for red main and go with a lighter valve spring on HPA but it won’t work well for anything other then High Pressure Air.

If you had success before it may just need a good cleaning. Lightly oil less is more just enough to make the surface look wet.

I run mine at 825psi tank input pressure and I can un screw the HPA tank and screw in a bucket changer with next to no adjustment over the chrono. This gives me 280fps with a .681 and detents with both HPA and CO2. Stock silver springs. I set up all my Phantoms this way. You can make them work at other pressures but I have found 825 to be most consistent.

[TheMacGruber]

This has been very helpful and I have some experimenting to do.

[Chuck E Ducky]

☝🏻exactly higher pressure helps that valve slam closed. I get an incredibly efficient shot count out of my Phantom on 12g and HPA keeping it tuned for HP without the need for a reg.

I get over 150 shots at 280fps on a hot fill out of a 9ci 3k HPA bottle. (I can shoot my Joyride empty 15 tubes and 12 round feed and still have a few shots in the tank) I do run a longer barrel 14” .681 with detent mod. That’s enough of an overbore to compensate for the crap paint and fluctuating sizes. I just let the detents do their job.

I can still get 42+ shots out of a 12g at 280fps above 60* with well timed shots. (As long as I don’t over shoot the 12g faster then the Co2 can expand) this is the same setup I use on HPA only difference is the source of propellant.

But you can adjust them down in pressure lighten up the pump stroke a bit but there are trade offs to consider.

That Turbine reg maxes out at 650psi and comes pre set at 450 that’s really low for a Phantom.

This may be your best bet ($14)

“Specifically designed for HK Army Performance Series Regulators.” (800-850psi range)

You would need to ask them if your reg falls in that category of “performance series”. Because it doesn’t specify say the kit will work with the Turbine reg. I would be surprised if a $150 reg would not handle rental marker pressures honestly but it is HK sooo 🤷🏻

https://www.hkarmy.com/products/hp8-...e&_ss=e&_v=1.0

Then again for $20 more you can get a reg with it. ($34) and know it’s compatible.

https://www.hkarmy.com/products/hp8-...3377851a&_ss=r

[SignOfZeta]

I supposed I could get 42 shots out of a 12g…but I’ve never managed to make a single tube of paint last an hour so I’ve never tried it. I consider 24 or so to be normal for situations where you’re being shot at. To avoid being pinned down out of air and paint at the same time there is some wastage and it ends up being 20 in real life.

From what I remember when I got a new tank last year HK’s “pro” stuff only does low pressure and the cheap stuff only does high pressure. Things may have changed though since the tank I got last year isn’t even for sale on their site anymore.

[Chuck E Ducky]

I count tubes not shots. I change out @ 32shots 12 round feed + two tubes then change out every 3rd tube. The ability to shoot 42 slow lets you easily shot 32 even over shooting the 12g some.

I get 30 on my completely stock CCM with an ICD lever screwed in the ASA and that’s a sniper I did zero efficiency tuning on. I do shoot all of my markers at 280fps regardless if a field allows for 300fps. It keeps them all shooting similar trajectory’s.

[Fossilhead]

Here's mine.
I've got a 36 45 setup I can use too.

But it's more fun like this.
I've just got an old ninja reg on the 36.

[TheMacGruber]

Thanks everyone, this was very helpful. I wish I had found a tank regulator that I liked at 800 (I wanted a cp reg but they went under just in time to make that hard).

The solution ended up being a combination of putting in a red hammer spring, and putting close to 300 rounds through it. After it all "wore in" it got very consistent and was easy to adjust to my desired velocity. I wasn't giving it enough time to settle in before making adjustments.