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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: C.ALLS on March 14, 2014, 04:37:23 AM
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I received my BSA R-10 MKII .22 today. It's my first regulated gun and to be honest I'm a little confused on tuning a regulated gun. The gun has a hammer spring adjustment as well as a regulator adjustment. I know that on all my other guns I've tuned that increasing hammer spring preload raises the guns fill range. Being that the BSA is regulated I would assume the hammer preload adjustment will have minimal effect till the regulator allows a higher pressure behind the valve? I'm sure I could figure it out with a full day of experimenting but I would rather go at it with a little more certainty. Any experts care to share their tricks/opinions?
I'm not looking to tune the gun into a power house and to be honest I may not even touch it (besides cleaning) unless I don't like the chrony results. From what I've read it should propel the 18.1 JSB pellets at around 835fps. I would like to possibly tune it to shoot them closer to 880-900fps.
Thanks
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I would chrony it first as they shoot well out the box (mine did) you may be near that fps as it is
all I did on mine was adjust the regulator pressure.(will need a chrony)
remove the stock, remove the stock screw. clockwise (going in)increases, counter does the opposite.(gold piece in picture.
(http://harryb.myftp.org:9090/bsar10reg.jpg)
havn't had time to play with the bammerspring but I don't have any plans to no time soon.
It was just fine out the box shooting in the high 800's, I adjusted and was shooting in the 1000's, turned it back a bit until I was shooting in the mid 900's
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I shot a string this morning. I'm shooting the 18.1 JSB pellets at 822fps. I'm at 3k feet elevation and it was only 28 dedegrees. The "dang" thing is CRAZY accurate lol.... I'll try adjusting the regulator this evening. Thanks for the info.
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*LOL* yes it's crazy accurate, you can give a nutter a vasectomy at 50 yards easily.
even though my s510 feels more refined besides lighter, it's hard to put down the r10. it just screams shoot me some more.
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Blatant hijack.... is your R10 more accurate than the S510? How fast is your R10 shooting.
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Tuning a regulated gun is trying to find the most efficienct hammer strike without losing power for the pressure your regulator is set at.... The ultimate power will be dictated by the setpoint pressure and the porting in the gun.... Given a set value for those, then you want to try a bunch of preload settings on the hammer spring and plot velocity vs. preload to get a curve like this....
(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaEfficiency1200_zpscdcebe24.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaEfficiency1200_zpscdcebe24.jpg.html)
You will note that after a given amount of preload, the velocity doesn't increase, all that happens is you waste air and lose shots.... This is on the "plateau" on the left side of the graph.... On the right side, the "downslope", the velocity drops sharply as you reduce hammer strike, the gun gets a lot quieter, and eventually you run into a situation where the velocity INCREASES after the pressure drops below the setpoint of the regulator.... IMO, if you want to shoot at such a low velocity, you need to reduce the setpoint pressure.... Where the two straight lines transition I call the "knee" of the curve, and that is where I tune all my regulated guns.... On that graph, I would use 4-5 turns out on the preload (from coil bind) because I'm getting 95-98% of the possible velocity but using the least amount of air to achieve that, and therefore getting the highest shot count....
Bob
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Blatant hijack.... is your R10 more accurate than the S510? How fast is your R10 shooting.
they are evenly matched, even the hw100. it's not the gun, it's the shooter that makes the major difference. although having a reliably accurate gun helps, accurate consistant pellets help, but at the end of it all the shooter determines how good the gun is.
but for a definitive answer. it's even. late last summer/early fall I was shooting in my back yard 40 yard range and I could pick up one or the other and be on target, switch back and forth each shot. they only felt different, the end result was the same.
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Tuning a regulated gun is trying to find the most efficienct hammer strike without losing power for the pressure your regulator is set at.... The ultimate power will be dictated by the setpoint pressure and the porting in the gun.... Given a set value for those, then you want to try a bunch of preload settings on the hammer spring and plot velocity vs. preload to get a curve like this....
(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaEfficiency1200_zpscdcebe24.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaEfficiency1200_zpscdcebe24.jpg.html)
You will note that after a given amount of preload, the velocity doesn't increase, all that happens is you waste air and lose shots.... This is on the "plateau" on the left side of the graph.... On the right side, the "downslope", the velocity drops sharply as you reduce hammer strike, the gun gets a lot quieter, and eventually you run into a situation where the velocity INCREASES after the pressure drops below the setpoint of the regulator.... IMO, if you want to shoot at such a low velocity, you need to reduce the setpoint pressure.... Where the two straight lines transition I call the "knee" of the curve, and that is where I tune all my regulated guns.... On that graph, I would use 4-5 turns out on the preload (from coil bind) because I'm getting 95-98% of the possible velocity but using the least amount of air to achieve that, and therefore getting the highest shot count....
Bob
So once I find the hammer pre-load setting that gives me the best efficency and velocity for a given regulator setting the correct way to increase velocity would be turning up the regulator slightly and do the same process with the hammer spring? Obviously I would reach a point where the ports would be the limiting factor but am I understanding the rest of the process correctly?
Then I could shoot till I get a rise in velocity and that would indicate I'm coming off the regulator?
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So once I find the hammer pre-load setting that gives me the best efficency and velocity for a given regulator setting the correct way to increase velocity would be turning up the regulator slightly and do the same process with the hammer spring? Obviously I would reach a point where the ports would be the limiting factor but am I understanding the rest of the process correctly?
Correct, but the limiting factor for a given port size will be the setpoint pressure, and eventually the pressure in the tank.... Up until you reach that pressure, the velocity will continue to increase (assuming you have enough hammer strike available to reach the plateau).... but of course the shot count will plummet because you are using so little of the pressure range between fill pressure and setpoint....
Then I could shoot till I get a rise in velocity and that would indicate I'm coming off the regulator?
You will only get a NOTICEABLE rise in velocity if you are running on the downslope part of the graph, with the velocity significantly below the plateau at whatever pressure you are running.... If you are only on the "knee" of the curve you are running as if it's an unregulated gun about 100 psi or so higher than the peak.... The shot string is so flat at that point you won't even notice when you hit the setpoint and you will be able to shoot 100-300 psi BELOW the setpoint before you even notice the velocity dropping to any significant degree.... That is the way I tune all my regulated guns, with the results I get quite a few extra shots below the setpoint.... Here is an example....
(http://i378.photobucket.com/albums/oo221/rsterne/QB%20on%20HPA/QBNinjaString1500_zps434961a3.jpg) (http://s378.photobucket.com/user/rsterne/media/QB%20on%20HPA/QBNinjaString1500_zps434961a3.jpg.html)
Notice that the useful string extends 200 psi below the 1500 psi setpoint which occurred at shot 53 out of 62.... the string ending at 1300 psi....
Bob
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You're really making this easier to understand and I am very grateful. I just spent some time with my gun doing some chrony work after some adjustments and this is the shot string.
3200psi fill 18.1 grain JSB
1-844.1fps
840.4
844.1
844.9
838.3
842.9
839
844
837.8
842.9
11-844.2
845.9
842.1
842.9
841
845.7
842.6
843.9
844.6
848.8
21-845.2
844
850.4
849.4
847
849.5
847
847.1
849.8
853.7
31-847.6
853.6
853.7
849.2
846.9
853.7
846.6
846.3
842
844
41-845
838.1
834.8
831.1
I read 1800psi at this point.
I increased hammer pre-load 1 turn and velocities raise 4-5fps through the string and the gun is a little louder. When I decrease spring pre-load 1 turn I get a drop in velocity through the string that averages 12-15fps so I believe I'm on the knee of the curve. What would be your opinion and suggestions? I can't tell you enough how much I appreciate your help.
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I would try 2 turns in on the preload, just to confirm that you are indeed on the plateau at about 855 fps.... and I would try 2 turns out, to see if the velocity drops even more, to something on the order of 800ish.... You don't need to shoot complete strings to confirm that.... Then it is a matter of simply deciding how much power you need based on the shot count.... You had 41 shots from 840-850 fps in the string above, so if we assume that was from 3200 down to 1800 (1400 psi drop) we can do an efficiency calculation for where you are now if we know the reservoir volume....
1400 / 14.5 = 97 bar x reservoir volume = total CI of air used at 1 bar
average FPE = ~29 x 41 = 1189 FPE
divide 1189 FPE by the total CI of air to get the efficiency in FPE/CI
IMO, I would not run more preload than you did in the above string, but I would seriously consider 1-2 turns less, you may be shocked at how many shots you gain by doing that.... The final decision will be to strike a balance between FPE and shot count for your purposes.... With only a 12-15 fps drop 1 turn out from where you are, that sounds very promising to me.... It would be like 4.5 turns out on the first graph I posted, which is where I ended up tuning that QB79....
If you absolutely MUST have more power, then you either have to increase the regulator setpoint (less pressure range = fewer shots) or increase the port sizes (with luck, you might just get more FPE with only using slightly more air).... but as you can see, leaning on the hammer spring won't do it....
Bob
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I would try 2 turns in on the preload, just to confirm that you are indeed on the plateau at about 855 fps.... and I would try 2 turns out, to see if the velocity drops even more, to something on the order of 800ish.... You don't need to shoot complete strings to confirm that.... Then it is a matter of simply deciding how much power you need based on the shot count.... You had 41 shots from 840-850 fps in the string above, so if we assume that was from 3200 down to 1800 (1400 psi drop) we can do an efficiency calculation for where you are now if we know the reservoir volume....
1400 / 14.5 = 97 bar x reservoir volume = total CI of air used at 1 bar
average FPE = ~29 x 41 = 1189 FPE
divide 1189 FPE by the total CI of air to get the efficiency in FPE/CI
IMO, I would not run more preload than you did in the above string, but I would seriously consider 1-2 turns less, you may be shocked at how many shots you gain by doing that.... The final decision will be to strike a balance between FPE and shot count for your purposes.... With only a 12-15 fps drop 1 turn out from where you are, that sounds very promising to me.... It would be like 4.5 turns out on the first graph I posted, which is where I ended up tuning that QB79....
If you absolutely MUST have more power, then you either have to increase the regulator setpoint (less pressure range = fewer shots) or increase the port sizes (with luck, you might just get more FPE with only using slightly more air).... but as you can see, leaning on the hammer spring won't do it....
Bob
200CC Bottle = 12.2CI
1189/12.2=97.45
What's a good number?
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you forgot to calculate the total CI....
12.2 CI x 97 bar = 1183 CI
1189 / 1183 = 1.00 FPE/CI
That's acceptable, but not stellar.... and exactly what I would expect if you are right at he beginning of the plateau (eg. at 4 turns out on my graph above).... 1 more turn out could easily increase the efficiency by 10%, and combined with the slightly lower FPE (~28 FPE?) could give you 50 good shots....
Bob
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Blatant hijack.... is your R10 more accurate than the S510? How fast is your R10 shooting.
last chrono before playing with the regulator and hammerspring
jsb 10.34gr
shots 1-10 200bar to 190bar 937.6-944.0-946.9-944.7-945.7-945.6-950.5-946.4-945.5-959.3
shot 11-20 190bar to 180bar 945.0-945.1-950.9-955.5-961.7-956.3-953.7-951.8-949.5-952.4
it's lower now.
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you forgot to calculate the total CI....
12.2 CI x 97 bar = 1183 CI
1189 / 1183 = 1.00 FPE/CI
That's acceptable, but not stellar.... and exactly what I would expect if you are right at he beginning of the plateau (eg. at 4 turns out on my graph above).... 1 more turn out could easily increase the efficiency by 10%, and combined with the slightly lower FPE (~28 FPE?) could give you 50 good shots....
Bob
I'll be sure to try a few turns out on my pre-load just to see what it can do but I'm thinking for my purposes (long distance pesting) I will end up back at my current tune but I could use the higher shot count tune for backyard fun. I was hoping to squeeze 30FPE out of this gun but when I turn up the regulator and experiment with the hammer spring I get some very inconsistent velocities from what I believe to be limited port flow? Overall I love the gun and getting 40 shots works for me.
On another note I'm going to try contacting BSA to see if they have a tool for testing and adjusting the regulator. I've had the valve apart and it would be easy to check the regulator output with a gauge and bleed assembly.
Almost forgot, Do you have a range for your efficiency numbers? What's considered poor,good, great, and ideal? Sorry to bug you with so many questions but you seem to have all the answers lol.....
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For most guns, if I can't get over 1.00 FPE/CI I'm disappointed.... Where I'm happy depends on the power, but for a .22 cal in the 30-35 FPE range I would like to see 1.10 - 1.20 FPE/CI.... My current long range .22 cal pester shoots 18.1 gr. JSBs at 957 fps average (37 FPE) on 1600 psi and I get 47 shots down to 1360 psi of which 45 are above 950 fps (max. was 962 for a 12 fps ES) from a 13 CI tank filled to 3000 psi.... That works out to 1.07 FPE/CI....
Bob
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Guys, new to PCP entirely but getting an R10 MK2 from BAR (Blackpool Air Rifles) in the UK. It's listed as 'Regulated 200 shots .22cal' which is radically different than what Pyramid here sells that is 40 shots at 990pfs. I know in UK they have FAC rules of no more than 12ft/joules or whatever. Can my regulated one (according to BSA is only 570 ft/s) be adjusted for more power like you guys are experimenting? I won't be tagging squirrel or wild boar but in the event a crow happens to be in my scope I'd want some power behind the pellet! John Bowkett is going to blueprint it but he doesn't correspond via E-mail.
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Guys, new to PCP entirely but getting an R10 MK2 from BAR (Blackpool Air Rifles) in the UK. It's listed as 'Regulated 200 shots .22cal' which is radically different than what Pyramid here sells that is 40 shots at 990pfs. I know in UK they have FAC rules of no more than 12ft/joules or whatever. Can my regulated one (according to BSA is only 570 ft/s) be adjusted for more power like you guys are experimenting? I won't be tagging squirrel or wild boar but in the event a crow happens to be in my scope I'd want some power behind the pellet! John Bowkett is going to blueprint it but he doesn't correspond via E-mail.
If it is from the UK then it is probably 12fpe unless it is listed as FAC gun. That will make a big difference.
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Tuning a regulated gun is trying to find the most efficienct hammer strike without losing power for the pressure your regulator is set at.... The ultimate power will be dictated by the setpoint pressure and the porting in the gun.... Given a set value for those, then you want to try a bunch of preload settings on the hammer spring and plot velocity vs. preload to get a curve like this....
You will note that after a given amount of preload, the velocity doesn't increase, all that happens is you waste air and lose shots.... This is on the "plateau" on the left side of the graph.... On the right side, the "downslope", the velocity drops sharply as you reduce hammer strike, the gun gets a lot quieter, and eventually you run into a situation where the velocity INCREASES after the pressure drops below the setpoint of the regulator.... IMO, if you want to shoot at such a low velocity, you need to reduce the setpoint pressure.... Where the two straight lines transition I call the "knee" of the curve, and that is where I tune all my regulated guns.... On that graph, I would use 4-5 turns out on the preload (from coil bind) because I'm getting 95-98% of the possible velocity but using the least amount of air to achieve that, and therefore getting the highest shot count....
Bob
First of all, i would like to say special thanks for sharing the precious info. Being a newbie i am unable to understand following points.
Blue Line in the Graph:-
Is it represent the velocity at given set point of regulator and size of transfer port. I mean to say, if i want to plot it in the graph. I have to shoot a string at given set point and plot it in the graph?
Red line in the graph:-
The red line is labeled as "Efficiency" in the chart. I think it represents the affect of "preload on hammer spring" on velocity. What is the procedure to plot these values in the chart?
I think, i should coil bond the spring. 1 turn out on preload and chorno the gun then plot the value (chorno result) for the 1 turn. Then 2 turn out on preload and chorno the gun then plot the value (chrono result) for the 2 turn and so on..........
Confusion about Efficiency (FPE/CI):-
I have already learned the formula of determining the efficiency of gun from you. But i could not understand how you plot these values in this chart.
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The blue line is a plot of velocity at various preload settings of the hammer spring.... If you change the setpoint pressure, or the port size, it will have difference values.... You only need shoot a shot or two at each preload setting, not a whole string....
The red line is the efficiency, in FPE/CI, plotted against the same preload settings.... To determine that needs either a few shots at each preload setting, or a very accurate pressure gauge....
Bob
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Thanks for the prompt reply
Pardon me for the stupid questions. But i know only one authentic person over here who can patiently answer my stupid questions.
I am still unable to understand from where to start?
At a given setpoint pressure, i should reduce the preload on hammer spring (1 turn out) and plot the chrono value in the chart. Also determine the efficiency for this setting and put it in the chart. The further reduce the preload on the hammer spring (2 turn out) and plot the chrono value in the chart along with the efficient for this setting and so on.
Where the blue and red line intersect each other will be the maximum efficient point for the given set point pressure, preload on hammer spring and port size. Am i right?
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The procedure you mentioned is correct.... However, the intersection of the two lines really has nothing to do with it (if you change scales, it will change).... You don't even need to plot the efficiency, as there isn't a lot you can do about it anyway.... If you select the velocity where the transition is occurring from the plateau (on the left) to the downslope (on the right), that is the best combination of power and efficiency for that combination of setpoint and porting.... I call this the "knee" of the curve, and it is where I tune all my regulated guns.... If I need more power, I increase the setpoint (or open the ports) and do it again.... If I want less power and more shots, I decrease the pressure (or I may restrict the ports) and repeat to find the new knee....
Bob
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You explain it in the way so that i can understand and also answered my followup questions which i have not asked yet.
Good teachers tells but best teachers explain. Best teachers are rear. They are more knowledgeable, tolerant, enthusiastic and kind. You are one of them.
Bundle of thanks for the guidance. Answering the stupid questions of an ignorant person require a lot of patience, especially when you are explaining an important point to those who have already some knowledge about it.
One again thanks for taking time, for the strength of knowledge you gave me and the patience.