Regulator question for AT-44 .22

[eddie40]

i would say that regulator is set way under the lowest pressure. and that why the pressure is not enough to hold the pressure of hammer spring. that is my guess if he turn it back the other way said counterclock wise to the set point he wants it should be OK.

[SpiralGroove]

Yeah Rallyshark,
Didn't think of that.  Set-point so low there is not enough pressure being passed through to the valve to keep the poppet seated.  My Huma reg. need to be turned CCW to increase pressure.
Kirk

[Rallyshark]

That is correct on the CCW turn to increase the pressure, but this one is out of adjustment apparently.  It is set at 124 bar.  I don't know if I screwed it up, or something happened during shipping, or what.  Nick at ASP said he thought it was out of adjustment too, and suggested sending me another one, which is what is in the works now.  I would gladly try to put it "back into adjustment", but I don't know how.  I definitely don't have to equipment or knowledge to put it back into calibration.  I think it would be better to get it sent back, so Nick can re-calibrate it, rather me making it worse or completely ruining the reg.  I'm not griping at this point or anything.  I know stuff happens sometimes.  I deal with customers all day that depend on me making stuff work, and I wouldn't be very happy if one them decided to fix something themselves, and only made it worse for me,lol!  I know this thing will be great when I get it all together and working

On that thought, what is the factory hammer spring tension setting on an AT-44 long?  Right now it's at 2.5 turns from minimum, and that seems like it will be the right ball park with the reg.  I guesstimate it was shooting in the 930s with 14.3 gr pellets at around 120 bar.  I may need to move it another half turn at most.  Does that sound about right?  That is the lightest pellet I'll ever shoot.

[SpiralGroove]

Hey Donnie,
You've got the right idea; be patient and wait for the new regulator from Nick.  Just send back the old (w/o messing with) and install the new one.  Don't worry about the hammer spring tension until you've installed the new regulator and see where the gun's velocity is at.

Good Luck

[Bwalton]

Donnie Have Nick set it for you let him what you want to do, if you tell me what pellet you want to shoot at what speed I can tell you exactly where o set it at.

[Rallyshark]

Hey Donnie,
You've got the right idea; be patient and wait for the new regulator from Nick.  Just send back the old (w/o messing with) and install the new one.  Don't worry about the hammer spring tension until you've installed the new regulator and see where the gun's velocity is at.

Good Luck

Thanks, that's the plan!  Bwalton, I want to keep the power pretty high, but I know there is a cutoff on where the efficiency will go through the floor.  The gun was shooting the 14.3 CP very well bone stock, so I'm pretty sure they had to be going near 1000fps(I didn't have a chrony at the time), and that's the lightest pellet I'll ever use.  I would like to keep it high, for when I shoot the heavier pellets too.  My favorites are the JSB 18.1s and the H&N 19.09s, but also have some of the JSB 25gr ones for when I decide to go after something a bit bigger than tree rats.  I'm hoping I can get the 18, and 19gr pellets in the low 900s and still keep the shot count above 30, maybe even 35?  It's a AT-44 long, and at 2.5 turns from minimum it was shooting the 14.3 CPDs around 940fps with about 120 bar.  I would love to hear what your opinion is on this!

[Bwalton]

My thoughts on the shoot count @ 30 with 900fps is doable, but you will have to mod the rifle for efficiency..

[zandrew]

With CPHP I was getting 50 shots per fill at 800 fps. The problem was when I went to shoot the Kodiaks which fly better at longer distances I couldn't hit anything. I had to reset it for 890fps with CPHP and I now get 40 shots with it. I have not modded my valve. I actually bought a spare cylinder so I would not have to mod my stock one. I filled the holes and installed the reg. No matter what I did I could not get over 650 fps but I was getting a huge shot string. Seriously I was getting like 80 shots.

What happened was my spare was a Canadian cylinder which has a different valve. BIG difference. I swapped the reg over to my stock cylinder and I get fine results.

[Rallyshark]

Thanks as always for the info guys!  I'm still learning here, so every little bit of info is great.  My replacement reg is on the way, so I'll be able too see where I'm at with it then.  The good thing about the Huma is that it is adjustable.  I'm going to try it at 130 bar first, and see what I'm getting with the stock valve/hammer spring adjustments.  I may order a second cylinder that I can mod and leave un-regged down the road.  It won't be as big of a deal if I mess that one up.  If I do that, I'm going to try and tune the spare un-regged one for max power with 25-28gr, but that's neither here or there right now.  Job one is getting the reg in and tuning it for the most power I can get un-modded while still getting 30-35 shots  

[zandrew]

Thanks as always for the info guys!  I'm still learning here, so every little bit of info is great.  My replacement reg is on the way, so I'll be able too see where I'm at with it then.  The good thing about the Huma is that it is adjustable.  I'm going to try it at 130 bar first, and see what I'm getting with the stock valve/hammer spring adjustments.  I may order a second cylinder that I can mod and leave un-regged down the road.  It won't be as big of a deal if I mess that one up.  If I do that, I'm going to try and tune the spare un-regged one for max power with 25-28gr, but that's neither here or there right now.  Job one is getting the reg in and tuning it for the most power I can get un-modded while still getting 30-35 shots

If you have a chrony go ahead and start shooting strings and recording the bar every 5 shots. Fill to 200 bar and shoot say 40 shots. Once you get a close idea of what bar setting you want say 130 bar you can short fill to 150 bar and shoot some more strings. Get strings for each pellet you plan on shooting. Once you have the data picking a regulator setting is as easy as looking for the fps of each pellet at its overlap point. Guessing will only have you pulling the regulator each time you want to adjust.

Oh and I am getting 30 shots at 890 fps, not 40 as stated above.

[Rallyshark]

Thanks as always for the info guys!  I'm still learning here, so every little bit of info is great.  My replacement reg is on the way, so I'll be able too see where I'm at with it then.  The good thing about the Huma is that it is adjustable.  I'm going to try it at 130 bar first, and see what I'm getting with the stock valve/hammer spring adjustments.  I may order a second cylinder that I can mod and leave un-regged down the road.  It won't be as big of a deal if I mess that one up.  If I do that, I'm going to try and tune the spare un-regged one for max power with 25-28gr, but that's neither here or there right now.  Job one is getting the reg in and tuning it for the most power I can get un-modded while still getting 30-35 shots

If you have a chrony go ahead and start shooting strings and recording the bar every 5 shots. Fill to 200 bar and shoot say 40 shots. Once you get a close idea of what bar setting you want say 130 bar you can short fill to 150 bar and shoot some more strings. Get strings for each pellet you plan on shooting. Once you have the data picking a regulator setting is as easy as looking for the fps of each pellet at its overlap point. Guessing will only have you pulling the regulator each time you want to adjust.

Oh and I am getting 30 shots at 890 fps, not 40 as stated above.

I will probably try and short fill it, and do a few shots tomorrow if I have time.  I'll play with the hammer spring a bit too.  I know each gun may a little different.  I know of others on here that are getting about 40 shots right at 900fps with the JSB 18.1s.  I've witnessed that one first hand.  His gun/valve is modded though.  His is the long, and so is mine.  I don't plan on monkeying around with the reg much, once I find the happy medium that works for my gun.  I don't want to get to crazy with modding the valve, until I have two of them.  That way I don't end up without a gun to shoot.  I figure the reg won't show up until Friday or Saturday, so I've got a little time to figure out a good starting point. 

[Rallyshark]

It's looking like 130 bar on the reg will be closer than I expected.  I just pumped the gun up to 140-ish bar(just below 150), and it was shooting the JSB 18, and H&N 19 gr pellets 910-915 range down to 120 bar.  It was still pushing the JSB 25 gr at 820s when I was down to around 115-120 bar!  Granted, the gauge on the gun could be off by a little too.  Unfortunately, I sent one of the 25gr ones high on the trap, and it blew through the back,lol!  I guess I need to do a better job of packing the rubber mulch a bit tighter...  Anywho, I'm going to shut up now, until I actually have the reg in the gun

[Bwalton]

something does not sound right the reg is set@ 130 and shoot down to 120bar 10bar @ how many shots? sounds like it was off reg? How many turns is the hammer out? When you get a chance pump up to the full 200bar, you should be within 2-3fps ES if you have a curve, then readjust the hammer.

[Rallyshark]

something does not sound right the reg is set@ 130 and shoot down to 120bar 10bar @ how many shots? sounds like it was off reg? How many turns is the hammer out? When you get a chance pump up to the full 200bar, you should be within 2-3fps ES if you have a curve, then readjust the hammer.

I don't have the reg yet.  I was just shooting the gun at a similar pressure that I will have the reg set at when I do receive it(hopefully Saturday).  I was just trying to get a general idea of things, before the reg shows up

[Bwalton]

  That makes sense

[Rallyshark]

Good news!  My reg showed up today, and I slapped it in the tube, and pumped it up.  I fired one clip through it, and no air leaks like before   So the first reg was the problem it would seem.  Unfortunately, it was dark when I got home, so no chrony time, and it is supposed to be bad weather for the next two days.  I'm now regretting my decision not to get a light kit for the chrony when I got it, so I could just do it indoors   I can tell it really seems to be packing a punch though.  It blew through 3 magazines and into the trap o rubber mulch...  I was also feeling a puff of air on my hand when I shot it (out of the stock).  Is that normal, or could the oring on the end of the cylinger/valve where it goes into the gun be leaking?  Or, could it be the one in the barrel?  I only shot one clip to make sure it wasn't losing air this time, so I'm not positive on how much air it was using.  From the rough reading on the tiny little gauge, I'm guessing it dropped about 20 bar on those 10 shots.  Like I said though, that's not exact by any means.  I don't know that I would have felt the puff of air, if I had it mounted back in the stock though.  I'm leaving it out of the stock, until I can get some chrony readings and play with the hammer adjustment.  I probably should just mod the stock, so I can get to that stuff without taking the gun out of the stock, but I'm trying to maintain some semblance of a warranty since the gun is new.

[Rallyshark]

Scratch that part about the puff of air, I'm a dummy!  It was the air coming from the hole in shroud that is normally covered by the stock...  I guess that's just there as an "air exit" hole, but it is obviously supposed to be there

[Rallyshark]

I rigged some LED lights for the chrony, and was able to shoot a few pellets through it.  It's shooting in the 870fps range with the JSB 18.1, and 860fps with the H&N 19.09 pellets.  Bwalton, I see what you mean about having to mod it for efficiency.  It is coming off the reg at 29-30 shots as it is.  It drops about 15fps with the hammer spring at 1 turn from minimum, and stays about the same from 2-3.5 turns from minimum(870fps).  I'm guessing any more hammer spring tension won't make a difference??  It was still slinging the 25gr JSBs close to 800fps, which isn't bad I thought. 

Where should I go from here?  I know you guys said I'll need to mod the valve if I want to get 30 shots at close to 900fps with the 18gr JSBs.  I considered ordering a spare short cylinder so I could have a spare valve to mod, and put the modded valve in the long cylinder, and the non-modded valve in the short one.  I just don't want to screw up my only good valve I have, if I get it wrong, and that would leave me the spare cylinder to use for when I want max power.  I don't want to raise the reg up from 130bar, since I'll get less shots right now.  As far as modding the valve goes, I need to plug 5 of 6 holes, and slightly enlarge the one that lines up with the transfer port.  Correct?  I shouldn't have to do anything to the gun itself should I?  Also, the modded valve will bring the velocity up as well right?  Sorry for all the questions, and the run-on thread here, but I'm learning   Thanks for the advice!

[pllagunos]

Actually it will bring velocity down a bit but it will make the gun more efficient  , I am not sure how it will work with the regulator but what I am sure is that you will need to play with hammer spring tension to be at the "knee" of the regulator. And yes you should open up the last hole to about 75% of the bore size, and it isn't difficult to plug the holes actually it is really easy, just make sure you don't damage the valve steam o-ring with brass burr, it happened to me once 

[Rallyshark]

Actually it will bring velocity down a bit but it will make the gun more efficient  , I am not sure how it will work with the regulator but what I am sure is that you will need to play with hammer spring tension to be at the "knee" of the regulator. And yes you should open up the last hole to about 75% of the bore size, and it isn't difficult to plug the holes actually it is really easy, just make sure you don't damage the valve steam o-ring with brass burr, it happened to me once 

I'm not completely sure about the velocity necessarily going down?  I know of another member on here that is shooting in the 900fps range with their regulator set at a lower pressure than mine is, I think.  They have modded their valve, but they may have modded the gun too.  I honestly can't remember now   I'm not disagreeing with you at all.  I'm just saying I've read different results.  What you're saying makes sense too.  Of course, if it's running more efficiently, I can possibly increase the reg setting and still get 30 shots.  Hopefully, Bwalton, or blackdiesel will chime in on this   At least, those are two people I know have knowledge with this gun.  How do I tell when the hammer spring is on the "knee" of the regulator?  Would that be in the zone where more tension decreases velocity and less does the same?