Low FPS

[trashcollector]

I don't remember having this much trouble reaching a proper fps. After an eBay trash collecting spree, multiple Tippmann A-5's, 98's, and one PCS US*5 are all having trouble breaking 250fps on an 800psi tank. All cycle with no leaks. The velocity screws are not restricting the flow. The paint to barrel match is ok. The tested have been cleaned and lubed. The paint is the 3 star from IoN.
I have tried stiffer spring either to no improvement or a loss in fps. A 1,200psi output tank and the stiffest spring yield 280-290fps but that just seems unreasonable. I did not replace the stock o-rings because I was hoping to use some of these with CO2 for outlaw ball. They all appeared in good condition.
Should I replace the valve and hammer o-rings with NBR instead? Are the old valves too restrictive?
I might be missing something obvious but I am too tired to think right now.

[trashcollector]

A 12gr with the bucket changer straight into the A-5 did not improve the fps. I wonder if it is a battery issue in the xradar chrono.

[FlightMedic938]

Anything bought 2nd hand, especially from EBay, needs to be cleaned and rebuilt with new o rings. I’d start there. Especially the front bolt o ring. Lots of air loss and terrible fps if the front bolt o ring is the wrong size or poor quality.

If you have macroline feeding the valve that needs to come off and replaced with steel braided line. Hammer and front bolt needs a couple of drops of oil every time before use.

[ClockworkSoldier]

If they're all having issues, I would rule out your tank and chrono first. All those markers should perform perfectly fine with either Co2, or HPA, as is. Never had any issues running either with any of my multitude of A5s or 98s, or my many other buddies, and never had to change out parts when swapping air sources.

[trashcollector]

Swapped the Duracell for another good Duracell. No change. I have a pressure tester and verify all my tank output pressures. 800psi and I just used it to tune my old ‘98 Autococker.
I did swap the front o-ring with a small increase but nothing significant.
Time for a complete rebuild. All of them 🙃

[FlightMedic938]

I don’t have any stock ones but from what I’ve read they need 850psi to shoot velocity. With a good cleaning, fresh o rings, and a little bump in pressure I think you’ll get there. Do you have a tank reg that outputs 850? If it’s a Ninja I think you’d be ok with adding one silver shim to bump it from 800 to 850

[trashcollector]

Just chrono'd at 280fps my only working 98c at sub 800psi using a Palmer's male stabilizer so it is not the tanks. Again, rebuild time.

[trashcollector]

No luck with the rebuild. 260fps max with a green main spring. 240-260fps range across main spring strengths. It shouldn’t be this difficult.

[FlightMedic938]

What barrel do you have on the 98 with the Palmers reg?

[trashcollector]

I threw a 14” Progressive on there. Normally a Freak setup.
The A-5 is a stock barrel.

[FlightMedic938]

trashcollector Try putting the aftermarket barrel on the ones you picked up. Stock barrels are very short and the porting is very close to the breech. Or cover the porting on the stock barrels with some duct tape. See if it improves.

If it’s not the barrel, front bolt, or main spring I guess it could be the valve spring or stem. That would be unlikely though, to have valve spring and/or valve stem problems with all of them. It could also be the detents but I’m sure you replaced those. If they lose their form the paint can roll around a bit which is going to hurt velocity.

[nak81783]

1. Low probability, but inspect valve stems. Ensure stems are threaded snugly through seal and into guide. Lose valve stems usually manifests with occasional to consistent farting. This assumes your older valve stems/guides are like newer FT-12 rental markers, of which I’ve been working on a lot lately.

2. Does your chrono correlate with another, perhaps one at your local field? I’ve seen 30fps differences between chronos.

3. Unlikely, but try a lower pressure tank, maybe starting around 700psi, and reducing in 50-100psi increments down to 500psi. Leave velocity screw where it’s at. If the valve and/or spring setups on all the markers have been modified, you may be past the sweet spot input pressure, which actually closes the valve faster, resulting in lower velocity. I realize you said a 1200psi output tank increased velocity some, but I can’t determine if you did that by itself or in conjunction with the stiffer mainspring, which would change the sweet spot. That said, when you try lower pressures, return all markers to how you got them in terms of valves, springs, and hammers, isolating the test to just lower tank input pressure. If you don’t have a lower output pressure tank, you could put all the guts of a newly purchased marker in your working 98 with the Palmer reg, using the Palmer reg to control input pressure. Not ideal, since it’s introducing another variable (parts/body swap), but perhaps worth a try.

[trashcollector]

1. I have an FT-12 that shoots 280. I forgot I had it. No farting in any of the cases but they will all get an inspection-depth inspection with time.
2. It does. I chrono’d my Flatline in the 260 range for IoN and that is what it chrono’d up there. Same with my M3+ and my local field. The xradar was bought new and doesn’t appear to be an issue.
3. I was getting along that train of thought. I tried a 725psi tank but I will take another Stabilizer I have and toss it into the valve/ASA of the A-5/98C’s, start low and work my way from there.

The A-5 has a hammer style that I have not seen before but it did not seem so far out of place. It is target number 2 aside from input pressure. Maybe it should be target number 1. I have to find my other hammers.

[trashcollector]

I found another hammer. The one I was using weighs in at 152gr and the one I found is 149gr. A quick search shows stock hammers at 150gr. I’m swapping valves.

[trashcollector]

I wonder if these stiff Captain O-ring ball detents cause enough drag to slow the cycle down. That would be the only common denominator between the 98’s and A-5’s

[nak81783]

I wonder if these stiff Captain O-ring ball detents cause enough drag to slow the cycle down. That would be the only common denominator between the 98’s and A-5’s

Try removing them. I have a project Spyder VS3 with dual detents. Using both caused too much drag, lowering velocity. One is sufficient against the feed force of my LT-R.

[trashcollector]

Try removing them. I have a project Spyder VS3 with dual detents. Using both caused too much drag, lowering velocity. One is sufficient against the feed force of my LT-R.

I replaced it with my TechT detents. They're too soft but much less drag for the testing.
The two biggest changes to fps were barrel length and isolating the Cyclone and R/T. The 14" Smart Parts one-piece brought me into the 280+ range. Blocking the bleed port with a body screw AND the 14" barrel put me well over 300fps @ 775psi through the Stabilizer. Blocking the bleed port and going back to the stock A-5 barrel put me back in the 280 range.
Using the longer barrel and bleed port block, I am going to work my way back through input pressure and main spring strength.

[FlightMedic938]

A TubE iS a TUbE lol Glad you are getting it worked out 👍

[trashcollector]

SOLVED - I believe the bleed port, Cyclone and R/T hoses and fittings were the main culprit. With a properly sized Freak insert and 14" tip, I am 320+ with the velocity adjuster nearly backed out. Thanks for helping me think through it.
I did check my chrono against a known value again and it was within reason.
With the softest spring and DocsMachine M4 tip totaling a 9" barrel, I'm still over 300. Tube is not such a tube in this case. I might try messing with the bolt o-rings again to see what happens. Thanks again nak81783 FlightMedic938 ClockworkSoldier

[ClockworkSoldier]

Awesome, glad you got it worked out! The RTs can certainly have a big impact on performance, if not set properly, and the Cyclone tubing can cause some issues if not installed properly. Although it's pretty odd to see all of the markers having those issues. I had to completely disassemble, and deep clean, the whole Cyclone feed and tubing on a more recent A5 purchase, to get it working properly. I still don't know how the previous owner managed to get so much nasty gunk and debris inside it all.

[FlightMedic938]

DocsMachine could make a killing making some 98 thread Freak backs 👀

[trashcollector]

Those and the A-5 Autococker-threaded barrel adapters.