New HUMA Reg - Unexpected (Poor) Performance

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stephfx

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Nov 19, 2018
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N/A, Belgium
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View attachment 1578684772_2789553715e18d164344c70.53824135_FXSL-Huma-Consistency-125bar.StringA.pdf

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View attachment 1578684794_1125711355e18d17a9bcc76.88841325_FXSL-Huma-Consistency-125bar.StringB.pdf



The Huma regulator, installed on 10-Nov-2019 in my FX Streamline .22, is yielding unexpected poor performance.



Initially, the output pressure was set at 120 bar.

10 days ago, since it didn’t give me the expected velocity at the optimum hammer spring tension for this pressure, I increased the output pressure to 125 bar.



Now, my SL shoots the JSB 18.13gr pellets at ~890fps, a velocity that is 4 to 5% below its “plateau” (i.e. peak) velocity for this reg pressure.



In order to check the consistency of the reg, I recorded a string of 27 shots with the new FX chronograph, and was shocked by the extreme spread: 32 fps.

Since I suspected the new chronograph of not being very accurate, I recorded another string of 50 shots with 2 chronographs at the same time (the FX and the LMBR). I obtained an ES of 24 fps from the LMBR and 25 fps from the FX. You can find the stats in the PDF attachments.



Given that the Huma Installation Guide states that Huma regulators are high performing with less than 1% fluctuation, I was expecting a single digit ES. Certainly not such a huge variation in velocity.

Could you please advise and tell me what might be causing this? Which parts of the rifle should I check? In which priority/sequence? Could the reg be the culprit?



Thank you in advance


 
I've noticed less than "normal" function for the Stormrider reg from PA. It always seems to function but sometimes I fill the rifle and the regulated pressure will go to cylinder pressure and need a few shots to settle to set pressure and other times it immediately holds at set pressure. Seems a bit odd but it hasn't failed to stabilize and function as set.
 
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@Glem - I shot several hundreds of pellets at 120 bar. But not many at 125 bar before these 2 strings. Maybe 30 rounds when determining the peak velocity at this pressure. Does the reg need to be broken in each time the output pressure is changed? I would assume so. You might have given a very good point. Thanks !

@Bandg - I have also sent Huub Andriessen an email to show him the shot strings. Will see if he suggests to send it back to him for testing. Unfortunately, on the SL, a reg pressure gauge cannot be installed (I read that some people do that when testing the reg on their Wildcat). Thanks for your input.
 
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That is very poor but they do say on their website it takes time to "break them in."

BTW, Here is the shot string from my low dollar Umarex Gauntlet which employs a $50 Ninja paintball bottle regulator.

819, 817, 819, 817, 820, 814, 817, 813. Total velocity spread 7 fps. Usually get a standard deviation of less than 3 with most pellets.
Click to expand...

thats what my gauntlet looks like. and my huma in my .25 wildcat has a spread of about 25 fps on average also. but its very accurrate. i just dont dwell on the shot string. i try to only use my chrony when setting up a gun for a tune. then just learn your gun. otherwise, it will drive u nuts listening to the guys who have a 7 fps spread. as long as my poi doesnt change i’m good. im not too OCD on the subject. 
 
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The extreme spead is not horrible. You may have a tin of bad pellets. I've had tons with like 1.2 grain difference, and tons with only like .3 or .4 grain difference in spead. 

I've used some Huma from time to time. I've noticed that they are ofen not what everyone cracks them up to be. I've got creep with them, leaks, and inconsistentcy. Once I bought one and it was missing an o-ring. Most of the time thet are good, not magically perfect.
 
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I if the reg is new yes it needs to be shot for a few tins , there is a white disk inside and it has to be opened and closed to seat in well , I noticed this after I rebuild them , I recently was tuning my gun , and some how a tiny piece of roing from my reg tester , got stock in the adjuster hole and it shut off air to the output side , I decided since I had to take it apart to totally replace all o rings clean it and polish it and replace seat , after this I set my reg pressure to 140 bar , I noticed with a hi quality digital gage , after loostening to bleed reg it stopped at 140 bar , then went to 140.1 and after like 10 min went up to 140.9 , so yes this can cause an ES so can a leaking oring , , this by the way settled in after 400 slugs now 140 bar is 140 bar and it never moves now , , while breaking mine in I also checked spread , Like david said it was accurate and this is what matters .



But it did stop this tiny fluctuation and it is not regulator creep it is so slight , I believe maybe this is what you talking about , like glem asked , how many shots threw it and is your ammo weighed to be same ,? I have had ammo not constant as well LOU
 
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Have you weighed and sorted the pellets? that plays a big role. For example, When I tune my streamline I like to tune for the middle of my grain choice. Usually for my .25 cal its JSB mkii 33.6-34.2gn so I tune for 885fps avg. with a gn weight of 33.9gn. In one single tin of pellets I have had gn weights from 32.8 - 34.8gn. Imagine what the FPS reading would be without sorting. I have multiple HUMA regs in my guns and they all are the bees knees. I am not paid by anyone or sponsored by anyone, I tell it as it is. I only shoot the best or build the best. 
 
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Hi Everyone - Thank you for all the feedback. Really appreciate it !



I already shot more than a thousand rounds when the pressure was set at 120 bar. At this pressure, the ES was ~15 fps, with tins from the same batch as today’s tins.

I'll shoot another couple of tins at this new pressure (125 bar) to see if the performance gets better.



Regarding the quality of the pellets: they are not weighed and not lubed. I just don't use those that have a bent skirt.

Weighing the pellets is definitely something I want to do, once I find a reliable digital scale that is affordable.

So far, I have only seen people complaining about drift and inconsistency. If someone can suggest a good/reliable scale make and model, that will surely help.



There is no grease/oil on the hammer spring. I understand that it would get sticky and this would affect the hammer strike.



I got a response from Huub Andriessen (Huma-Air), 12 hours after I sent him an email. Wow !!

He's basically saying this:

- Huma-Air have a very strict quality check. Max spread in output pressure must be less than 1 bar, so less than 1 % fluctuation.

- He suspects that the HST and regulator pressure are not balanced, which can result to poor valve timing and to velocity inconsistency.

- He assures that an ES of 4-5 m/s (i.e. 13-16.5 fps) should be easy to obtain.

- He suggests to shoot slowly (at least 10 sec between shots).

No issue here. I checked the time stamps recorded by the FX chronograph and the interval between shots is at least 11 seconds.

- He thinks that 125 bar for a velocity of 890 fps might be too low reg pressure for the Streamline.

Well, here I don't know what to think… The peak velocity is 930 fps at 125 bar. I reduced the HST to get 890 fps (so peak fps minus ~5%). I thought it would be not too far from her sweet spot...



Sooo… If I don’t manage to get a better consistency at 125 bar I might have to try at 130 bar, which is the output pressure of the factory reg, if I’m not mistaken.


 
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I've read efficiency is usually better (all things being equal) at higher pressures. The claims were it closes the valve faster with less bounce. The negative is you have a smaller window from max pressure to falling off the regulator but the higher efficiency while on the reg means it uses less air and makes up for that. Worth running a comparison anyway. 

Note. This is an all things being equal comparison. For example, you can also get better efficiency with a larger plenum at lower pressures but that is related to less pressure drop during the shot cycle. 
 
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Lyman grain scale for reloading. Excellent scale

1578765147_9688289275e1a0b5b3f1904.19725243_DCC6B08F-6B0B-4FDB-A896-9122E7040635.jpeg




You may want to look into taking the reg out and cleaning it. One time i had some very odd fps spreads, it happened right after I replaced a air tube o ring. A small spec of rubber from the oring found its way into the inlet of the reg and caused all my issues. I disassembled the reg, re-lubed the washers lightly with fine silicone oil and I have not had an issue since. I cant even blame that on the reg. It was all a fluke from my oring replacement. 
 
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Thanks Gaberossi. I'll keep this advice in mind !! Re/ the Lyman micro-touch 1500, I looked at it some time ago, but found many people not very happy with it. I believe you when you say that it is excellent for you. But there might be some quality control issue. Seems to be a lottery: either you get a good one or one that you cannot rely on. Given the price, I'm hesitant.
 
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@DanieIL Yes, I remember that M Dubber said that higher pressure may help with accuracy, because the projectile accelerates quickly, the valve closes faster, hence lower risk of having turbulence when the projectile exits the muzzle.

On the other side, I also remember that E Rowe stated that the gun should be tuned at the lowest reg pressure that gives the desired velocity. And in his Impact Master Class video, he tuned the .22 cal at 125 bar for a peak velocity of 920 fps and then down to ~875 fps. From there, he recommended to test the accuracy by small increment/decrements (max 10 fps) until the sweet spot is found.

A few years ago, Bob Sterne recommended to determine the so called "plateau" velocity, and then to tune at 3-5% below this peak velocity.

Right now, I'm really working in a trial & error mode... And that's how I learn :)

@Rj That's good to know ! But is 920 fps not too fast? I'll try to shoot at a faster velocity for sure. Not to close to the peak velocity though, as I don't want to waste air (want a decent shot count per fill).
 
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