Paintball

[idkfa]

Originally Posted by Rednecksniper

a buddy of mine had an LP phantom for a while. he had it set more for consistency rather than efficiency. he was still hitting 35+ shots, but they were +- 1 every shot. nelsons weren't really made for LP, but ive been tinkering with making one.

Same. I am hitting 295 fps at ~ 500 psi, light main spring, light valve spring, and splattttttt's open bolt mod with my Phantom. I have some ideas, but I am not entirely sure how how or why it is actually working. Not exactly true-LP, but I am going to try to push it to 400 psi next.

[russc]

Someone ought to make a Phantom valve/powertube/hammer combo for LP.

Increasing the diameter of the sealing face, along with a wider, higher flowing power tube and a hammer bored out and made heavier to accomodate would give a lower valve sweetspot, allowing for more volume to pass while also reducing or eliminating valve "pop" when cocking.

[idkfa]

That would be an interesting thing to experiment with.

My low(er) pressure Phantom is shooting great, but it is about 30% less efficient from my estimates. My theory is that I have reached a balance point where the weak main spring can still open the valve enough, due to the weaker valve spring (I took a stock spring and cut some rings off) and lower pressure pushing against the cup seal, to get a full velocity shot. I am going to try to lower the input pressure and possibly try a valve spring with one less spring removed.

EDIT: I forgot about the weak main spring actually, I was surprised/shocked that it shot at playable velocities. I was using it a few weeks ago with a vertical 3.5 oz tank, weak main spring/valve spring, and open bolt face, indoors and getting 250 fps. The ONLY change I made was to add a stabilizer, drop it to around 500 psi, and it was shooting 295 fps.

I am going to check the pressure on the stab as well. I know it is somewhere between 300 psi and 600 psi based on the screw position.

[MrJR]

I'm stunned at what I'm hearing here. It seems to go against everything we've said/been told about 12 gram efficiency. Has me wanting to do some testing of my own.

[russc]

It's ok to question the man once in a while...

[Jubszy]

I just want to add one thing - regged 12g setups are for summer play only. Outside temperature drops below 20 deg.C and whole sweetspotting goes bye-bye, plus dropoffs and frozen regs. Unregged-old valve setup wins here.

[oerllikon]

Wow, this surprises me... All you hear about, is how sheridan setups arent efficient... Weird, but awesome at the same time. I got 20-25 usable shots off of my 03 in semi. It didnt have a pump kit. I think around 300 psi. Its good to see someone put an old myth to rest.
Im a little jealous, i just got my grey ghost friday, lol

[russc]

Originally Posted by Jubszy

I just want to add one thing - regged 12g setups are for summer play only. Outside temperature drops below 20 deg.C and whole sweetspotting goes bye-bye, plus dropoffs and frozen regs. Unregged-old valve setup wins here.

Not necessarily. The valve sweetspot isn't going to change just because of temp changes, but dropoff and frozen regs are definitely a factor. I don't think an unregged setup wins, though...

Consider that the 2k+ gun I first tested sweetspotted at 240 psi. That means the co2 does not necessarily have to reach its normal pressure of 850 psi. As long as it's somewhere above that 240 psi mark, it'll keep working. I guess it depends on how much pre-reg expansion you have, but let's just assume that the volume before the regulator drops the "fill %" by half, or doubles the volume in the cartridge.



At freezing point, CO2 will be at 500 psi according to these graphs, until it hits 15% fill. It remains to be seen how much liquid would be shot through the reg and wasted, but you can see that the gun would still function better than your average 12g gun.

This also applies in the summer where many guns are vapor locked. A 50% fill in the pre-reg volume at 100 degrees F still gives you around 1200 psi. Most guns lock up, but with good fittings the regged setup should work perfectly.

[Rednecksniper]

i am going to make an LP phantom next, after these other 6 projects are done.

im aiming for below 300psi, i think its attainable. 3" volumizing rear air, light valve spring with medium main, custom powertube and more open internals. MAXIMUM VOLUME! F*** efficency, its a pump.

[EDDAKA]

ooooh. Damn i love you russc.

i just ran a couple 12'ies through my S5(running at around 300 psi) with a palmers fatty and i was getting a good 35 solid shots before a 1 shot drop off! Sweet!

Also it didn't seem to make much of a difference if i shot fast or slow.