Shot string from my R3 .25 Long. HST adjustment question.
Finally got my order for JSB 25.4gr pellets in from Pyramyd so I was able to do some Chrony testing this weekend. I’m pleased with the consistency of these shots strings. Now I just need to see how it groups with some long distance shots. On the second shot string of 88 shots it cut a peanut size hole on my target at 13 yards.
Would lowering the average velocity involve a just minor adjustment to the HST or would I have to adjust the regulator as well?
Filled to 200 bar. First two shots started of high for some reason on this shot string
Here’s the second shot string. even more consistent
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Don’t worry about the first shot (935)………. 😉
Leave the regulator/gun to settle in and redo the exercise after some 1500 shots…..
You’re doing just fine for now I think……….. 😀
Cheers……..
Yes I did. It was 100 bar. I forgot to log it on the second shot string. I’m to sure of where that first shot at 935 came from. Im almost tempted to take it out of the string.
Lurker,
Did you happen to record the pressure reading at shot 85?
Thanks!
GabeG
OK here are some better graphs thanks to Aigunner who sent me these very nice speadsheets that he put together for analyzing the FPE and shots counts.
Guys, adjusting the regulator is the LAST thing you should do, please…
LT, the numbers look good. But you certainly can make it better. The gun can be adjusted to standard deviation <3 with extreme spread <12 fps, and also reduce the variation between shots, as Dr. Edgun just said. If you decide to adjust regulator, remember to mark the original location and the new location you changed. You can make a simple graph (speed vs HST) in each reg change. This will help you to know where you are during adjustment. I have posted a step-by-step protocol on reg/HST adjustment for my Matador: http://talonairgun.com/forum/viewtopic.php?t=22808
Hope this is helpful.
Enjoy the tune.
Regards,
Endo
Thanks for advice. It is much appreciated. I’ll try to change the scale on the chart. Also shoot a few more fills and shoot some long range targets, then adjust the HST down a bit.
LT, that second string is not that bad. I (think) that I have found out that, on a completely calm day, speeds up to 940 give the same accuracy as speeds in the 880-910 range. I spend way too much time at the local gun club shooting 100 yard targets.
I really think that anything over 910, with any kind of a side wind blowing, produces larger groups and more fliers.
Kazzz is killer at 937 fps but, he is lucky enough to have access to a 100 meter indoor range!
You could try a little less HST and see where you are at. If you don’t get a fps spike for the last few regulated shots, you are golden!
If you get the last couple of regulated shots spike, you either need to refill a little more often or turn the reg pressure adjusting screw in clockwise just a little, turn the HST down at least 1 turn and then slowly increase it and see where you are.
The HST and reg set pressure work in unison.
Before you adjust the regulator, you could try ordering McMaster Carr part number 9559K13. It is a Teflon O ring that will replace the copper O ring in the Matador’s transfer port. I got my R3 25 long last Sept and it had been taken apart during shipping. The copper O ring was replaced with a rubber one. The rubber O ring would not stay in place. It would shoot out of the barrel after a couple of shots. VERY loud when it did that!
I ordered these Teflon O rings and they needed to have the ID opened up a little to match the transfer port’s ID. The stock Teflon O ring’s smaller ID might slow the speeds down without you having to adjust anything else.
If you do decide to adjust the regulator, I feel that I need to warn you: you probably won’t get it set right the first time and you will have to go from there.
I actually like tuning my Matadors. It takes me about 20 minutes to adjust the reg. I am happy with a 3-4 fps shot to shot variation and a max variation of 10-12 fps.
Yoda and Endo are really anal and have gotten their Matadors to shoot even flatter shot strings.
Nice charts !!!
You put the 100 fps increments and all you can see is a strait line. Can you change it to 10 fps?
My .22 R3 doesn’t always like 200BAR+ pressure also, so I always fill to 195 just to be on the safe side.
To answer your question, you can lower your HST and shoot a string. If you have a bell curve you need to clockwise your regulator. As you do that, your speed will increase so you need to lower your HST a little more also. Shoot a new string and repeat the process until you are satisfied.
Brain surgeon Edgun set his .25 R3 to 890 fps as I recall and has the 4 fps spread. I never managed to make him tell if that’s the extreme spread or the standard.
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LT, your first graph and info was easier for me to comprehend than your second one. Just getting old, I guess.
I agree with Ed; the last thing that you want to do is adjust the regulator but, sometimes, you just have to!
I think that I have found out that anytime that I adjust the reg, the next fill can give me numbers that will be off compared to subsequent fills. I think that the regulator needs to take a “set” after it has been adjusted. After adjusting the reg, I shoot a full fill, refill and see where I am at. If the numbers haven’t changed, I am good to go. If the shot string has changed, it will give me an idea of what I need to do.
I think that you can disregard that first 935 shot. The reg might have had it’s “set” from the last fill. If you don’t see another 935 and you are happy with speeds in the 915 range, you are good to go!
If you want to be in the 890 range, try adjusting the HST down a little and see if you get a spike at the end of the fill. If you do, you need to turn the reg down just a little more.
When adjusting the reg, you always have to turn the HST screw out and then slowly turn it in until you get the max speed. The HST and reg’s set pressure work in unison.
For at least a few of us, getting the Matador set up perfectly is fun!