Counter intuitive or obvious: why lower pressure is faster?
So here’s the deal, I adjusted my regulator (from jdsairman) down to 1776 psi from 1960 which was down from the original 2100 that I specified when I bought it.
I selected this new air pressure after shooting down the bottle until my trajectory started to drop, which occurred around 1600 psi. 1776 was the closest without going below that number.
Now for the part that has me amazed: At 1960 psi the trajectory began dropping when the power wheel was below about 4 plus or minus a couple of minor points. With the psi now at 1776 the trajectory is still at it’s flattest with the power wheel at 1.0 or even the little below that setting that you can drop down on the wheel. So less spring force applied to the hammer gets better results.
The only thing that I can figure out is that the pressure holding the valve shut is now much lower and therefore less force is required to open it.
Just to fill in the blanks, it is a spinloc Condor with a .22 12″ barrel.
I’m going to remove the Condor hammer weight to see if I can get enough adjustment to have some room to work with.
All Replies
Thanks to all for the replies.
Mrnewbie: If your REG is set to 1776psi (how the heck did you measure this?),
answer: Well, I disassembled the reg, and wrote down the current stack arrangement. Knowing it was 2100psi, or whatever is closest to that, I was able to calculate the single spring force constant. Then using the formula for spring washer force calculations came up with a new arrangement that came out, at least on paper, to 1776psi.
I’ll try to answer your questions about why I have the reg; there are quite a few takes on what benefits regulators offer and all seem to have their logical expectations. I got mine to flatten the bell curve to hopefully a line no matter what power I want to shoot. I feel that the power wheel is a useful feature and have found it quite good. I know others here don’t use it or find it worthwhile and that’s all good too. I’m looking for repeatable results and within the skill parameters I have I’m nearly satisfied with the Condor. What I’m looking for now is getting rid of the fliers that seem to plague my otherwise happy shooting. I’m just trying stuff out and reporting here what I find.
Thanks again.
addition to MRnewbie, how do you set up your tophat? it plays very important role in velocity. You may try to adjust it longer.
I Also have a JDS/Etac combo..and with the 12″ I can shoot anywhere from 830fps down to 600fps or lower or whatever I want.
My reg is set around 2200 to 2300psi.
In order for the Reg to do its thing, You need to open it up ALL THE WAY every time.
If the PW is at 13 and you hit it..out comes a.22 at 800 or so fps.
If the PW is at 1 and you hit it..out comes a .22 at a far lower fps, and its adjustable with less PW/Hammer weight.
Handy for low power shooting…there is a balance point.. between the PW/Spring/Hammer…
Its the REGULATORS job to regulate..forget the POWER WHEEL…
Set the power wheel where it opens the REG all the way every time !!!
A PW set at 1..is not openeing the REG enough to let it do its job..thus you are setting your pellet FPS with the PW. If you wanted to do this..why buy the REG?
Adjust with the REG…take the PW..set it to where it opens the REG every time with as little hammer weight as poss…take out the adjustment screw..throw it away.
The reg will get you a Standard deviation of under 10fps (we hope)..every time.
If you need to adjust..adjust the REG..
You have a Reg…..thats why you bought it…to replace the PW.
If your REG is set to 1776psi (how the heck did you measure this?), then shoot from 3000psi..down to 1776psi..then its time to air up.
Seems to me a REG set at 2100psi shooting a .22 on a 12″ should get you around 800fps. I don’t know if 800fps is perfect..or the best speed to shoot at..but at least it will be consistent. Shoot JSB’S 18.1’s or 15.9’s.
Sounds like this is exactly what is going on. And how we adjust for a bell curve when no reg. is involved. Higher pressure=need for more force to open valve.
KnifeMaker
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Send It to me and I will tell you what it’s set at and set it to what you want.
You can set 2 regs the same and they will read different. The washers are not consistent at all.
Only way is with a setup that reads the output pressure.