Author Topic: BSA R10 MK2.177 shot string analysis help ?  (Read 954 times)

solder

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BSA R10 MK2.177 shot string analysis help ?
« on: February 08, 2017, 10:04:53 AM »
901 899 897 900 900 898 901 903 902 903
909 904 904 908 910 907 912 911 900 901
902 900 902 901 902 903 902 903 903 896
902 903 893 896 897 902 901 901 899 899
905 905 897 902 904 894 899 902 903 900
896 891 891 889 887 883 877 871 874 875

200bar fill after loosening hammer spring 2 turns out. Originally shooting about 927fps with 10.5gr  CPUM. What does this tell me? Should I stop here and leave the regulator at the stock setting? Any help greatly appreciated!


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rsterne

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Re: BSA R10 MK2.177 shot string analysis help ?
« Reply #1 on: February 08, 2017, 10:32:54 AM »
Looks like a pretty good string for the first 51 shots, it appears to drop off the reg. in the last row.... It depends on what you are trying to accomplish....

Bob
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solder

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Re: BSA R10 MK2.177 shot string analysis help ?
« Reply #2 on: February 08, 2017, 11:34:24 AM »
Thanks Bob. I am looking for low ES and consistent accuracy at 50 yds. I am not really too concerned with shot count, 30good shots is plenty. I did notice an improvement ia accuracy by dropping FPS from 927 to 900 or so. Do you think going lower would help? Would it be best to adjust the hammer spring only and leave the regulator alone? Is it tuned to the knee yet?
« Last Edit: February 08, 2017, 12:02:40 PM by solder »
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rsterne

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Re: BSA R10 MK2.177 shot string analysis help ?
« Reply #3 on: February 08, 2017, 04:27:34 PM »
No way to tell how close it is to the knee from a shot string.... You need to shoot a couple of shots at various preload settings and find out what the plateau is, and where you are in relation to that.... You want to plot a chart like this....



The knee on that chart is at 4-5 turns out from coil bound....

Bob

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Motorhead

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Re: BSA R10 MK2.177 shot string analysis help ?
« Reply #4 on: February 08, 2017, 05:03:03 PM »
For the R10 and an OEM Regulator ... pretty good & IMO pretty typical performance profile.
Tho seeing the ES spread gives credence to why many bite the $165 bullet and install a HuMa regulator in the OEM's place.  * Tighter ES for most who do.

There is also 20-30% more shots there to be had by using a hammer debounce devise such as BSA's blast tamer or an SSG devise.  Another option is a lighter hammer striker core and respringing it.
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solder

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Re: BSA R10 MK2.177 shot string analysis help ?
« Reply #5 on: February 09, 2017, 07:51:54 AM »
Scott, thanks for the response. I have noticed some variability in my shot strings with ES varying between 9-20 over 30 shots with fill pressures of 3100psi to 2600psi using CPUM 10.5gr pellets. I want to try some AA or JSB 10.34gr. pellets. The most consistent strings are when I fill to 2900psi. I intend to add a blast tamer and HUMA when the warranty runs out. I don't want to do something that will void the warranty, but improving accuracy is always a plus. It's nice to keep on learning and improving, even at 68yrs old.   I am very satisfied so far with the out of box performance of the R10 MK2. The first generation of aftermarket regulators seems very good and will no doubt improve over time.
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