Regulator break in

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PerkyVal

PerkyVal

Member
Nov 22, 2017
862
24
Wisconsin, United States
I recently put a Huma regulator in my Impact and have put a about 130 round thru the rifle.

I haven't done more than a quick tune so far, and the numbers so far are unimpressive, and to my mind unacceptable.

After tuning my Crown, at an average of 848fps I'm getting an extreme spread of 8, and a SD of 2.5

With the Huma in my Impact at 852fps I'm getting an extreme spread of 19, and a SD of 5

With the stock FX regulator I was getting slightly better numbers than with the Huma...so far.

The question i have is how many shots fired do y'all think it will take to break in the regulator?




 
I recently put a Huma regulator in my Impact and have put a about 130 round thru the rifle.

I haven't done more than a quick tune so far, and the numbers so far are unimpressive, and to my mind unacceptable.

After tuning my Crown, at an average of 848fps I'm getting an extreme spread of 8, and a SD of 2.5

With the Huma in my Impact at 852fps I'm getting an extreme spread of 19, and a SD of 5

With the stock FX regulator I was getting slightly better numbers than with the Huma...so far.

The question i have is how many shots fired do y'all think it will take to break in the regulator?

~~~~~~~~~~~~~~

Keep us posted, Val.

I have a Huma on the way. I will delay installation based on your results. I sincerely hope that the Huma's reputation -- like so much else we hear -- is not merely hype.

Good luck, and be as patient as possible. Maybe the Huma will live up to its reputation.



Click to expand...


 
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You mentioned having done a quick tune after swapping the regulator. Can you elaborate on what you did? The before and after velocities are very similar, but if the setpoint of the Huma is different then it may be necessary to tune to a different velocity.

Also, any chance you are working with a different tin of pellets now? A 1% ES is about the best that can be expected from a very good tin...meaning those manufactured in a different batch may open up the ES / SD.
 
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You mentioned having done a quick tune after swapping the regulator. Can you elaborate on what you did? The before and after velocities are very similar, but if the setpoint of the Huma is different then it may be necessary to tune to a different velocity.

Also, any chance you are working with a different tin of pellets now? A 1% ES is about the best that can be expected from a very good tin...meaning those manufactured in a different batch may open up the ES / SD.
Click to expand...

Essentially all I did was open up the valve travel, then adjust the reg to get approx the same fps as is on my Crown. Then I closed the valve adjuster until the fps started to drop. I already had the hammer spring adjusting screw maxed out, so I set the power wheel to 3 for the reg adjustments


 
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Okay that gives us a clue. You described the hammer spring adjuster as being "maxed out". There is only one hammer spring setting for a given regulator setpoint that will yield the best consistency (ES / SD). If it's maxed out, that suggests it's probably not at the optimum setting so let's step through adjusting it.

For starters, let me be clear that the transfer port setting is irrelevant at this point, however I do prefer to tune with it wide open. But strictly speaking, we don't care about the transfer port right now. To find the optimal hammer spring setting, keep increasing it until the velocity no longer increases*. Then back it off until the velocity is about 97% of that maximum. So for example, if your max velocity was 880fps, dial the hammer spring back until the velocity drops to about 854fps.

Now with the hammer spring adjusted in harmony with the regulator's setpoint, you can adjust your velocity using the transfer port. When set up this way, any transfer port setting you use should yield a tight ES / SD. However anything you do with the hammer spring adjuster will compromise that consistency. I've seen a number of folks disappointed by that reality but that's the way it works. To be fair, it is true that a very precise regulator will fare better in this regard but there will alway be some negative impact in practice due to things like temperature deltas and regulator creep.

* Note if you can't find a setting where the velocity plateaus and you still have some room to adjust it higher, it's s non-starter. You'll have to use a stronger spring or reduce the regulator's setpoint. If that's the case, let's have a followup so as not to overcomplicate things right now. 
 
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To avoid confusion, a FX Impact has a fixed transfer port. The valve adjuster is a whole different animal, and the main reason I swapped my Crown for a Impact.

Regarding regulator break in, it should perform right from the start, and numbers should be consistent.

Sometimes the ES can drop a bit over time, but it should show consistent numbers from the start.
 
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It seems that most people dont think a regulator test needs much time to break in.

I'm thinking I'll run another 100 or so pellets through it to make sure, then start the process over. Its possible that the way I successfully tuned my Crown won't work the same because of the extra 100mm barrel length, which means a lower reg setting and hammer spring preload.

I'll back off the hs adjustment screw back to stock, put the hs wheel on high, and start the reg preasure very low, and slowly turn it up until I'm getting the spread I want. Then I'll slowly turn in the valve adjuster for efficiency.

Seem logical?


 
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A search pulled up some info on the Impact's valve adjuster that Michael gave based on a conversation with Fredrik at EBR, stating it controls "how far the valve can actually be opened". That would mean valve lift in the common lingo so conceptually it would be something like a bump stop for the hammer to keep it from driving the valve open beyond some limit. A bstaley O-ring hammer buffer does the same thing, though I'll grant the possibility they achieve it differently.



With that understanding, opening it up as you did would be a suitable first step. Then set about finding the velocity plateau by adjusting the hammer spring and then bring it back to 97%. Once that's done, you can use the valve adjuster if you want to bring the velocity down from there.
 
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How long were you waiting between shots? From my experience humas usually aren't the quickest for refresh rate in my experiences and that could be something to think about as well.
Click to expand...

Yeah, that was mentioned in the Huma docs. I consciously tried to wait at least 3 seconds, or longer between shots although I have to admit I may have been quicker from time to time
 
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1-2% es is pretty normal especially if you're NOT weighing / sizing pellets. A weight difference of just 1/2 a grain can cause a fluctuation of 5~ fps. That right there is .5% ES jump for most. If shooting @ 850~ fps that makes 2% es = 17 fps. Shooting into / against wind has similar effects so if you had reasonable distance between you and chronograph take that into consideration.



Generally an inconsistent hammer strike is more to blame than a regulator...make sure the hammer + bore it slides in is clean.



the only way to 100% absolutely without a doubt confirm its the regulator is to use a digital psi gauge or a real good eye on an analog gauge and measure the regulated psi prior to your shot, if its over 2% difference in pressure from shot to shot then its your regulator and not tune / hammer related. Regulator has 1 job, and that is to maintain steady / consistent pressure between it and the valve. Provided its doing its job within spec (within 1% pressure from shot to shot) then you must look into other factors as a the culprit.


I highly doubt your Crown will do 20 full pressure ranged shot strings in a row all with an ES of 8. Not trying to insult its just not common to see a rifle put out 1% es strings for its entire life time and time again, if your crown can do the above then you have a freak of nature.



1/2 gr Pellet weight fluctuation = 5 fps

+/- 1% regulated pressure differential = 5 fps



The above two common issues we can only do our best to eliminate will always be present and inherent in pellet/air rifles...thats 10 fps spread in just the nominal accepted range of pressure differential and pellet weight differential.



Its near impossible to retain 1% es over every shot string for the life of any rifle.



Good luck!




 
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Yeah what I try to do when running regulated gun over the chrony is count to 5 then fire and repeat. That way that's at least consistent.

I also tune my regulated guns how Jason (nervoustrig) does. I find the max speed at the regulator setting. Then I decrease hammer tension until fps is about 20fps slower than max fps. If that's not the speed I want to be at then I adjust reg pressure and try again until I reach my desired fps. However not sure how valve adjuster works on impact.
 
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1-2% es is pretty normal especially if you're NOT weighing / sizing pellets. A weight difference of just 1/2 a grain can cause a fluctuation of 5~ fps. That right there is .5% ES jump for most. If shooting @ 850~ fps that makes 2% es = 17 fps. Shooting into / against wind has similar effects so if you had reasonable distance between you and chronograph take that into consideration.



Generally an inconsistent hammer strike is more to blame than a regulator...make sure the hammer + bore it slides in is clean.



the only way to 100% absolutely without a doubt confirm its the regulator is to use a digital psi gauge or a real good eye on an analog gauge and measure the regulated psi prior to your shot, if its over 2% difference in pressure from shot to shot then its your regulator and not tune / hammer related. Regulator has 1 job, and that is to maintain steady / consistent pressure between it and the valve. Provided its doing its job within spec (within 1% pressure from shot to shot) then you must look into other factors as a the culprit.


I highly doubt your Crown will do 20 full pressure ranged shot strings in a row all with an ES of 8. Not trying to insult its just not common to see a rifle put out 1% es strings for its entire life time and time again, if your crown can do the above then you have a freak of nature.



1/2 gr Pellet weight fluctuation = 5 fps

+/- 1% regulated pressure differential = 5 fps



The above two common issues we can only do our best to eliminate will always be present and inherent in pellet/air rifles...thats 10 fps spread in just the nominal accepted range of pressure differential and pellet weight differential.



Its near impossible to retain 1% es over every shot string for the life of any rifle.



Good luck!



Click to expand...

I had not weighed the pellets for initial tuning, but they were washed and inspected. However the same tin was used for the Crown, and Impact on that day. The Crowns result was from a 16 shot string in which one shot was not recognized. So net 15 shots.

You make a fair point tho, and I will do a longer shot string and see what changes.






 
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Actually it is not necessary that the regulator provide a supremely consistent pressure, and in fact most do not. A well tuned regulated rifle will hold a tight ES over a wide pressure range, just as a well tuned unregulated rifle produces a tight ES on the sweet spot of its pressure range. That may be a pressure range of more than 500psi. For example, you might get a 1% spread from 2500psi down to 2000psi.
 
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Properly tuned you can get long string with very tight ES. The 2 strings are 7 months apart on the same gun.

Created: 02-02-2018 06:47:01 PM

Description: .30 WARP COBRA
Notes 1: 3650psi fill
Notes 2: reg set 2400psi
Distance to Chrono (FT): 3.00
Ballistic Coefficient: 1.000
Bullet Weight (gr): 44.750
Altitude (FT): 0.0
Temp: 47 °F
BP: 30.10 inHG
Shots
# FPS FT-LBS PF
44 807 64.72 36.11
43 808 64.88 36.16
42 807 64.72 36.11
41 808 64.88 36.16
40 811 65.37 36.29
39 813 65.69 36.38
38 814 65.85 36.43
37 810 65.20 36.25
36 812 65.53 36.34
35 808 64.88 36.16
34 810 65.20 36.25
33 811 65.37 36.29
32 808 64.88 36.16
31 807 64.72 36.11
30 812 65.53 36.34
29 813 65.69 36.38
28 812 65.53 36.34
27 813 65.69 36.38
26 807 64.72 36.11
25 815 66.01 36.47
24 817 66.34 36.56
23 815 66.01 36.47
22 812 65.53 36.34
21 808 64.88 36.16
20 812 65.53 36.34
19 814 65.85 36.43
18 812 65.53 36.34
17 811 65.37 36.29
16 812 65.53 36.34
15 811 65.37 36.29
14 815 66.01 36.47
13 817 66.34 36.56
12 811 65.37 36.29
11 812 65.53 36.34
10 817 66.34 36.56
9 814 65.85 36.43
8 815 66.01 36.47
7 811 65.37 36.29
6 809 65.04 36.20
5 814 65.85 36.43
4 817 66.34 36.56
3 817 66.34 36.56
2 815 66.01 36.47
1 806 64.56 36.07
Average: 811.82
StdDev: 3.15
Min: 806
Max: 817
Spread: 11
True MV: 812.09
Shots/sec: 0.07
Group Size (IN): 0.00

Created: 09-02-2018 07:12:58 AM
Description: WARP .30 16.1" barrel
Notes 1: 2900psi reg set
Notes 2: 3500-2500psi
Distance to Chrono (FT): 3.00
Ballistic Coefficient: 1.000
Bullet Weight (gr): 44.750
Altitude (FT): 0.0
Temp: 48 °F
BP: 30.02 inHG
Shots
# FPS FT-LBS PF
28 853 72.31 38.17
27 855 72.65 38.26
26 856 72.82 38.31
25 857 72.99 38.35
24 861 73.67 38.53
23 858 73.16 38.40
22 860 73.50 38.49
21 856 72.82 38.31
20 857 72.99 38.35
19 860 73.50 38.49
18 860 73.50 38.49
17 858 73.16 38.40
16 856 72.82 38.31
15 858 73.16 38.40
14 857 72.99 38.35
13 858 73.16 38.40
12 859 73.33 38.44
11 859 73.33 38.44
10 859 73.33 38.44
9 859 73.33 38.44
8 857 72.99 38.35
7 861 73.67 38.53
6 858 73.16 38.40
5 861 73.67 38.53
4 863 74.02 38.62
3 862 73.85 38.57
2 860 73.50 38.49
1 862 73.85 38.57
Average: 858.57
StdDev: 2.32
Min: 853
Max: 863
Spread: 10
True MV: 858.86
Shots/sec: 0.08
Group Size (IN): 0.00
 
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Dairyboy,

I'm glad to see that, and the long string results are what I expect from a high end regulated airgun. 

I fully expect my Crown is doing it, and if my Impact won't, I'll mess with it until it does, or sell it.

I do know the Impact right out of the box was, and got even better with the stx barrel. But that was with the smaller pellets.Things got weird when I moved to the 33.95gn pellets, and then with the addition of the 700mm barrel.

So I expect it's all on me at this point, especially considering the new Huma.


 
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A search pulled up some info on the Impact's valve adjuster that Michael gave based on a conversation with Fredrik at EBR, stating it controls "how far the valve can actually be opened". That would mean valve lift in the common lingo so conceptually it would be something like a bump stop for the hammer to keep it from driving the valve open beyond some limit. A bstaley O-ring hammer buffer does the same thing, though I'll grant the possibility they achieve it differently.



With that understanding, opening it up as you did would be a suitable first step. Then set about finding the velocity plateau by adjusting the hammer spring and then bring it back to 97%. Once that's done, you can use the valve adjuster if you want to bring the velocity down from there.
Click to expand...

I don't mean to sound like I think I can explain the valve stem adjuster better than Fredrik, but maybe in a way that made it easier for me to get my head around it. How far the valve can open relates to how long (time duration) it's open allowing positive airflow to drive the pellet down the barrel. If we start with the VSA removed or backed out far enough to offer zero travel restriction, the valve will travel the farthest (for the given hammer spring tension that is set) and thus be open allowing air flow the longest amount of time. If the valve is open expelling air for say 0.25 seconds (arbitrary number), and the pellet exits the barrel in 0.20 seconds, the last 0.05 seconds of airflow is wasted air. I understood the primary purpose of the VSA was to adjust the time the valve was open so it closed and stopped the airflow at approximately the same time the pellet leaves the barrel. This is indicated by the point where turning the VSA in to restrict valve travel first shows a decrease in FPS. I would believe this to be maximum efficiency in achieving the velocity produced by the reg pressure and HS settings in play. You can adjust the velocity down further to get to a given velocity with the VSA, but I thought its primary purpose was efficiency tuning, while the reg and HS are the primary tools for achieving a given velocity.

I mention this because when I got my Impact X 700mm .30 cal, I was told it would be leak checked and tuned for the JSB 44.75s before it was shipped. When I got it, it was shooting right about 860 FPS. I realize now it was not really "tuned", but simply set to a common velocity that is a good starting point. Once I started verifying settings, I discovered if I backed the VSA all the way out, I was shooting over 900 FPS. By adjusting the velocity down with the VSA, the reg pressure must remain higher. This starts moving the system from a "lower pressure, higher volume" system to a " higher pressure, lower volume" system. I have always assumed it was better to have lower pressure, with more volume, pushing the projectile with steady pressure increase up to the point where it leaves the barrel. Any thoughts?
 
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Chuck, 

If I understand your point, VSA essentially fine tunes how long the valve is open, and not necessarily a primary way to adjust fps.

If this is correct, the the VSA should be the last adjustment made, and only to the point when the fps drops a little, thus increasing efficiency, and perhaps helping with harmonics.

Is this correct in your opinion?


 
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