60 SHOT JSB STRING NEEDS A LITTLE HELP
This 60 shot JSB 15.8 gn .22 cal. string is a little ratty at the beginning and the end. Basically the FPS is all down hill from 1055 FPS to a low 0f 886 FPS. That’s a big spread but other than the ratty jumps in FPS the groups are reasonably good at 50 yards.
When grouped in 15 shots the SD is 16.6, 14.0, 11.4, & 45.9 with FPE of 37.7, 34.8, 32.2, & 31.6.
Even the last group of 15 gave me a reasonable 1 1/2″ group with 2 fliers.
FILL PSI 1760…ENDING PSI ABOUT 1095
1,055.17
1,054.34
1,051.60
1,021.34
1,041.46
1,049.04
1,011.53
1,036.11
1,043.26
1,033.46
1,028.81
1,001.81
1,024.02
1,018.85
1,016.96
1,006.98
1,013.90
1,005.23
998.34
1,004.14
1,006.48
1,001.65
997.77…..PSI 1518
996.04…..PSI 1507
989.04…..PSI 1496
977.78…..PSI 1485
977.86…..PSI 1474
975.73…..PSI 1463
973.22…..PSI 1452
973.69…..PSI 1441
967.23…..PSI 1430
969.87…..PSI 1419
969.40…..PSI 1408
965.30…..PSI 1397
962.69…..PSI 1386
962.24…..PSI 1375
952.62…..PSI 1364
957.44…..PSI 1353
952.92…..PSI 1342
949.85…..PSI 1331
947.03
947.25
938.80
940.11
935.68
901.00
926.87
922.63
999.58
912.96
994.41
982.06
988.00
904.57
989.39
984.62
998.10
887.78
895.73
886.74
My Condor likes JSBs 15.8 grain pellets better than the heavier pellets I’ve tried. I just ordered 25.4 gn JSBs.
I’ve locked the TH in place at 0.069-0.070″ with blue locktite.
I’ve moved the Condor added hammer weight to in front of the hammer spring leaving me with a 48.7 gram hammer and a little extra tension on the spring.
The Power Wheel is set at 6.
I don’t understand why this setup has not seen a rapid drop off in FPS. I figure if I can work out the rattyness in the beginning and end, it will even be better than I think it is now.
Your ideas would be appreciated.
All Replies
Nothing wrong with 30 good ones SavageS. I was shooting 2-3 different pellets and getting nearly 60 and then I happened on to what looks like an obtainable 60 or more good shots with one pellet. And with my lightened hammer it is using less air. It’s not as good as a regulated tank could give6but it’s only a 2″ POI drop over the 60+ shots.
With the lighter hammer and shooting just on the down hill slope may give more accuracy than shooting both sides of the curve. You would know each shot would be a fraction lower rather than wondering if it has gone up and is now starting back down.
Next time out will be 75 shots with the PW turned down probably just by 1 on the wheel.
SAVAGESAM, Using your perimeters or 1000 to 900 FPS good shots, I now have 52 GOOD SHOTS 😀
Actually, I’m counting it as 63 Good Shots from about 1040 FPS @ about 1650 PSI down to 860 FPS @ about 1008 PSI.
I got a 75 shot string with a fairly consistent gradual decline in FPS and still no significant jaggies or drop off.
Thanks Pab for the good advice. I still seem to go the wrong way with PW adjustments but you saved me many steps. With my EnLightened Hammer the PW adjustment is extremely sensitive. Just 1/4 of a number on the dial makes a difference of acceptable or not.
I am through for now at 50 yards with the 15.9 JSBs. I’m looking forward to trying them at 100 yards and then step up to 25.4 grain JSBs to see what the lighter hammer can do with them, if anything. Then a barrel change to 12″ .177 to see if the High Flow valve and lightened hammer can do the trick.
Nope, But I had a thought of starting over using fishing weights 😮
…. .. …. ..
I did lower the PW to just a little below the 7/3 group and lowered the fill to start at 1775 PSI. The following graph is crowded with the RED being the new group with 175 PSI less start pressure. I was surprised that the 1st 15 shots were jaggy & on the up hill slope. Could it have been the smiggen lower PW ❓ I expected it to start @ 1050 FPS & all be slowly down hill. I’ll adj. back that smiggen & see. Otherwise, I’m happy with this steady slope as it gave fair groups & I only had to drop down 1 Mil Dot for the last 15. There was not a sudden drop of FPS & the ending tank PSI was 1050 with 888 FPS.
Haven’t your thumbs fallen off yet? 😯 😎 😀 😆
Shot 90 today with the PW turned up 2 notches. Severe jaggies for the first 35 shots then a long slow decline of FPS.
The 1st 2 groups of 15 were very loose.
At 60 shots the FPS were OK so I got in another 15 shots.
I got the best grous with the lowest PW setting, the RED line on the graph:
I will revisit the setting for the RED LINE and start with less PSI & add a few shots to the end.
I saw where on the previous 75 shot string I made an error on the starting PSI. I edited it to read Fill 1950 PSI instead of the error of 2950.
Here is the data from Saturday’s shoot:
Fill 1950 PSI
Shots 1-15
797.74…..approx. PSI 1950
898.79
960.94
922.07
990.91
903.22
921.30
960.63
1,013.47…..approx. PSI 1905
964.69…..approx. PSI 1899
1,005.81
975.02
987.83
985.34
992.69
ending PSI 1865
Avg.FPS 952.0
Avg.FPE 32.1
SD 56.0
Shots 16-30
1,024.71
986.71…..approx. PSI 1801
1,011.44…..approx. PSI 1788
1,050.96
1,050.50
1,007.48
1,019.88
1,029.59
1,038.51…..approx. PSI 1706
1,051.96…..approx. PSI 1692
1,037.54
1,040.48
1,047.41
1,049.86
1,041.19
ending PSI 1675
Avg.FPS 1032.5
Avg.FPE 37.7
SD 19.2
Shots 31-45
1,047.95…..approx. PSI 1610
1,043.17…..approx. PSI 1596
1,043.44
1,042.09
1,038.60
1,037.62
1,031.00
1,028.28…..approx. PSI 1512
1,024.63…..approx. PSI 1498
1,021.00
1,019.88
1,014.41
1,015.09
1,007.23
1,006.73
ending PSI 1485
Avg.FPS 1028.1
Avg.FPE 37.3
SD 13.7
Shots 46-60
1,004.56…..approx. PSI 1400
999.00
989.61
991.31
988.16
984.62
981.35
979.92
981.11
973.77…..approx. PSI 1304
976.83…..approx. PSI 1293
971.19
968.70
962.31
961.47
ending PSI 1300
Avg.FPS 980.9
Avg.FPE 34.0
SD 12.5
Shots 61-75
959.57
958.65
953.44
956.68
951.12
936.19
936.70…..approx. PSI 1204
943.34…..approx. PSI 1198
943.12
938.88
936.12
925.24
921.79
914.68
929.93
ending PSI 1150
Avg.FPS 940.4
Avg.FPE 31.2
SD 13.8
Honestly, the only way, I think this has been my best shooting since I bought my Condor last year. It could have looked better if I started out adjusting POI to the right but I didn’t know if it was the cross wind or me. Next time out I may find out if I over adjusted.
I can’t quit yet. I’m to damn stubborn. At least I think it would be a mistake to continue turning the PW down. And I won’t know if I have the ultimate adjustment until I turn it back up 2. I had a heck of a time getting the double graph to flatten and convert to .jpg format.
It is all worth it to finally get a 5 shot sub 1″ group at 50 yards. Ooooh yeah, 7/8″ center to center. And that was the last 5 of 75 shots with average speed 925.55 FPS and average air pressure of 1168 PSI.
Anybody got suggestions, shoot! ❗
Everybody gather around and get ready to punch the L O L cuz Lurker #1 is about to cough up pictures of targets that were shot towards on Saturday.
Yes, I didn’t ask for advice before adjusting the PW and the beginning of the string went poop. I just turned it down by 1 number! Who’d a thunk what a disaster could happen?
The 1st shot, a DUD, was slow and LOW by 3 1/4″. The rest of the 1st set of 15 hit within 2 3/4″ of each other. The next 15 gave a group of 1 7/8″. There was an 8-10 MPH 90 degree cross wind so I didn’t adjust the scope until thelast 15 rounds.
I like to mix things up so after the 3rd set I killed the turkey on the top.
Targets 5-7at the bottom, were 5 shot groups.
Target 5 on the right I used to dial over the POI to the right. Target 6 has 3 small holes and one fat one. Last target #7 gave me the most trouble trying to make 5 out of 1 small hole and 2 fat ones.
The following graph is this outingin red and the previous one green.
The lower PW SCREWED UP the 20+ shots with a severe case of the jaggies. Darn, that left me with only 55 shots that were better than before.
I would liked to shoot another 15-20 becuz the POI had only dropped 1″ or half as much as the previous, green string. I must have made a mistake readind the tank PSI as it was strange; Fill 1950, shot 16-1815,shot 31-1610, shot 46-1400, shot 61-1240, ending 1150.
I’ll have to switch to my computer to post the FPSs
If anyone deserves a good shooter, its Lurker 😎 😎
Lol. 75 shots makes 30 sound like poop. Congrats on the work you’ve done. She sounds like a keeper.
SAVAGESAM,
Sorry about the delay in reply. I had a reply that didn’t go through, my fault, and then I decided to change it anyway.
30 good ones would be great for a hunt but not necessarily good enough for an hour or two at the range. I’ve experimented with using 2-3 different pellets and that worked for 2 pellets anyway. I just haven’t been able to get any tight groups with Eun Jin 32.4 grain pellets. I was probably shooting them to slow in the 800’s with my enLightened Hammer 🙂
Like Pab & Edward suggested, more PSI finally got to the up side of the curve and then lower PW setting smoothed it out some. Possibly 1 more down on the PW wheel will be enough to eliminate the jaggies and maybe tighten up the spread?
I wonder about the accuracy of the up hill side of the curve because the over pressure is initially blowing around the pellet slowing it or somehow causing a little drag and I think it could sometimes effect the path. Would probably have to clamp the rifle down and have more accurate pressure reading to tell. But, just maybe that’s the reason for an occasional “flier” 💡
Nothing wrong with 30 good ones SavageS. I was shooting 2-3 different pellets and getting nearly 60 and then I happened on to what looks like an obtainable 60 or more good shots with one pellet. And with my lightened hammer it is using less air. It’s not as good as a regulated tank could give6but it’s only a 2″ POI drop over the 60+ shots.
With the lighter hammer and shooting just on the down hill slope may give more accuracy than shooting both sides of the curve. You would know each shot would be a fraction lower rather than wondering if it has gone up and is now starting back down.
Next time out will be 75 shots with the PW turned down probably just by 1 on the wheel.
Looks to me if you filled to 1500, you’d have 30 good ones from 1000+ to 900+. What’s wrong with that?
Graph of 7/1/10 SHOTS:
The jaggies at the low end are greatly reduced. Perhaps a little lower PW will help smooth it more.
Here is a combined graph of the strings of 6/30 & 6/27/10:
The Verticle Scale is different making areas of the double graph look flatter.
WOW ❗
You were right on for 3 or 4 things Pab ❗
With the combination of a little more air, 190 PSI more, and turning the PW Down, we found the UP HILL Side of the Curve,
Smoothed the FPS down,
AND GOT A WHOLE LOT MORE GOOD SHOTS ❗ ❗ ❗
I had to build up my spread sheet to accommodate 75 SHOTS ON ONE FILL ❗
If I could get as many good shots on the up hill slope we’d be looking at a string of 120 SHOTS within a 2″ vertical POI ❗
Am I over using the exclamations ❓
Oh, I thing I’ve discovered something else very interesting.
The 1st shot now being on the Up Hill side of the curve was like a dud, the invariable throw away off target shot. It registered 742 FPS and the string then jumped up to 985, 956, 960 981 and on up to top out at 1046 on the 15th shot.
Then pulling the tank to check the PSI with the pump, I would think the 1st shot of each string should start out low.
OK, the 2nd string starts out just a little low at 1019.88 then jumps to 1040, 1046, 1042, 1043, 1042, 1043, 1041, 1040, 1036, etc. So the 2nd string was in the realm of the Maximum velocities at these settings and also started a little lower after the PSI check with the pump.
Due to Chrony error I averaged shots30 &32 to get the 1st shot of the 3rd string.
NOW, 💡 HERE IS WHERE THINGS CHANGE 💡
For the final 2 strings of 15 after checking the PSI as above, THE 1ST SHOT OF EACH STRING BECOMES THE HIGHEST FPS FOR EACH STRING ❗
So, the 1st shot on the up hill side of a slope, after fill or PSI check with the pump, is a throw away. But this is not true on the down hill slope. Isn’t that neat ❓
OK, I’ll shut up and show this one fill 75 shot good string:
FILL 1950 PSI <<edit 7/4/10 was not 2950>>
742.09
985.82
956.91
960.33
974.47
954.04
981.75
983.82
988.96
992.29
1,003.81
1,024.97
1,019.71
1,036.91
1,046.51
Ending PSI 1815
Avg.FPS 976.8
Avg.FPE 33.9
SD 70.8 Would show much better without the 1st shot
shots 16-30
1,019.88
1,040.39
1,046.23
1,042.81
1,043.71
1,042.99
1,043.80
1,044.16
1,041.46
1,040.12
1,036.11
1,025.06
1,025.23
1,021.43
1,018.68
ending PSI 1610
Avg.FPS 1035.5
Avg.FPE 37.9
SD 10.2
Shots 31-45
1,014.85 I fudged this shot due to chrony error.
1,011.02
1,002.31
1,003.97
997.69
996.13
986.47
985.58
982.38
979.44
985.50
979.52
967.85
965.23
967.62
ending PSI 1400
Avg.FPS 988.4
Avg.FPE 34.5
SD 15.6
Shots 46-60
976.28
969.09
956.23
965.46
960.63
956.91
953.67
950.45
945.62
944.81
939.46
938.37
933.95
932.15
929.79
ending PSI 1240
Avg.FPS 950.2
Avg.FPE 31.9
SD 14.1
Shots 61-75
937.64
930.65
928.36
930.15
918.15
895.80
910.01
913.72
918.99
906.12
910.76
897.13
900.33
898.32
900.40
ending PSI 1090
Avg. FPS 913.1
Avg.FPE 29.4
SD 13.8
Sorry, I’m to tired to calculate the SD for the 1st string minus the throw away 1st shot but it won’t be great anyway.
The 2nd string appears to have the best SD if I calculated correctly.
So, which way do I go to get a better SD
❓
benneeb0y,
I believe you are absolutely correct ❗
That’s how I prefer to do it but when I don’t have the range to myself, for some stupid reason I change up.
Thanks for bringing this to my attention. Hopefully I won’t make that mistake again.
Oh cool I thought I was the only one. Guess it does look a little funny lol 😳 !!!
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Oh, once you start shooting 100 yards, you are gonna get REALLY fussy with the string. You have to be otherwise your groups will be all over the place….!!