New PCP owner needs advice on tuning process

Jump to latest Follow Reply
L

lamarkeiko

Member
Jun 22, 2017
129
2
Oregon, United States
I've had my new Hatsan AT44S-10 QE .22 cal for just over a week now. I have 7 different pellets I've been shooting, and I have found two that group excellent, a couple that are fair and a couple that shoot all over the place. I have my new crony now, which I shot a 30 shot string this morning with one of my fair shooting pellets. I started shooting at a max fill of 2900 psi/200 bar, and ended at about 1500 psi/100 bar. My goal is to get about 20 accurate shots before recharging again. I'm attaching a copy of the shot string. I know that we want to keep the ES as small as possible, but I don't know what is considered good. If I'm correct, a lower power setting on the gun will give you more accurate shots with a smaller ES. Does it make any difference on what pellets are used while adjusting the power, as long as they're the same? Does this gun look to be set a little high on power when looking at the shot string? I would appreciate ideas of what you PCP veterans do when you set up your guns.
Thanks
Lamar

3395e3e6a09646554d1e4f8fb04f2d66.jpg
 
Welcome! I have a question that will likely be asked here a few times. How comfortable/confident are you about taking your gun apart? This needs to be known before we(the forum) start talking about hammer spring and trasfer port adjustments, regulators and fill pressures. If you don't want to tune the gun yourself then sending it to a tuner, bwalton comes to mind for Hatsans, with what you want for a shot count or power tune would be the best way to go. So whatya say?

Also how about a shot string with a heavier pellet? You might see a few more shots. As a base line I have my S500 in .177 tuned for power right now and I get 30 shots with an ES of 5.6, and a SD of 1.4. That's what you would call tight. Again welcome to the addiction and keep your feet together and arms tight to your sides and you jump down this rabbit hole :)

John E

Forgot to say the pellets I'm using in this tune are H&N Sniper Magnums in .177. They weigh 15g and move along at 875-880fps. Good enough to knock down rimfire egg silhouettes at 75yd.
 
Upvote 0
Wish I new the Hatsan products better. But my comment is stop at the 20 shots. And numbers will be much better. Did you try the 18gr jsb to get that pellet slowed down. None of my FX products like it past 900 fps for accuracy. There is a new redesigned jsb monster 25gr also to slow it down. If you look up BWalton on the forum, he loves your product and will give good advice. I'm sure you will get some more advice from guys on this forum also that will get you going also. Be patient and you will get some good info here to get you burning those 50y targets under .5".
 
Upvote 0
Thanks John for the quick reply back. I've looked at a couple You tube videos on adjusting the hammer spring on my Hatsan, and I have no problem with doing that. I have two different cans of H&N pellets that seem to shoot very accurate. One is the H&N Baracuda Hunter at 18.21 gr. I haven't shot a lot, but have gotten 5 shot groups under 1" @ 50 yd.
The other is H&N Baracuda Match @ 21.14 gr which I have shot the most with consistent groups under 1", and once a 5 shot group at 3/8" c-c at 50 yds. To my surprise, the one pellet I have that shot the worst was the JSB 18.13 gr Diablo Exact, which I seem to see more people rave about. I will probably want to get a regulator in the future, but I would first like to see what's the best I could do with this gun unregulated. I do prefer shooting a heaver pellet. I believe it will provide me with more foot lbs of energy and accuracy at 50+ yards, which I'm interested in. With that said, can you tell me your process order in tuning?
Lamar
 
Upvote 0
Monkyshine, I was still writing a reply when you answered back. I would be happy with a good 20 shot string. The only reason I shot 30 the first time was so I could see the extremes of the high and low fps in the green zone on my Hatsan pressure gauge. I think somewhere in the 900 fps range would be good for my heavier 18 to 21 gr. pellets.
Lamar
 
Upvote 0
First thing would be to lighten the hammer spring. I'm not sure about adjustments in the Hatsans but if you can back out a hammer spring screw as opposed to cutting the spring back that would be better to start. By doing that you should start to see more of a bell curve in your shot string as opposed to the downward line you get now. You may loose some fps but will likely gain a few more shots in an acceptable curve. Make small adjustments and record your beging location each thing you change before shooting over the chrony each time.
 
Upvote 0
I like what John says, I do shoot an unregulated gun with zero problems just for the record. I would like to hear your groupings at maybe 875, no more than 900. Turn the hammer spring tension down and start shooting again. Dont get discouraged, the pellets that shoot good at that speed may fail you at slower speeds and the others may become the winners. 1/2" at 50 yards is my minimums. I know you can get that. Extreme spreads of up to 20 I tolerate and 5-6 sd good. Use a ballistic calculator like chairgun pro and punch in your numbers and you can view all the paremeters of your shooting. For the record all my guns are .25 calibers and I like heavy pellets but I do pay attention to all the nation members and local friends who shoot .22.
 
Upvote 0
Thanks guys for the replies back. The you tube video says to turn the hammer spring screw 1/2 turn at a time and then try a string. So I'll start turning clockwise to reduce the power. I have a lot of Crosman Premier HP 14.3 gr pellets that shoot fair groups at 50 yd. Can I use those pellets to tune, or should I be using my heavier H&N pellets that give me the best groups, since those are the ones I'll be settling on for my best grouping.
Lamar
 
Upvote 0
I'm thinking I need to make a graph something like the one I copied and attached so I can see comparisons of changes. When you say bell curve, are you meaning the fps of the curve starts low, then rises to a peak, then starts dropping again? How many shots should I be doing in a shot string, and what psi should I start at? My guns max fill is 2900 psi.
Lamar
 
Upvote 0
Is 30 shots like I did the first time a good string measurement? That is about where I hit the end of my green area of 100 bar on my pressure cylinder. I also have two cans of pellets that didn't shoot very accurate for me. They are both 18+ grains in weight, which is the same as the H&N Hunter pellets that gave good groups. Maybe those would be good sacrificial pellets to use for tuning. Am I looking at something wrong there?
Lamar
 
Upvote 0
I haven't did any adjustment of my hammer spring yet. I wanted to get recorded shot strings of some different pellets and weights for comparison before I made changes. I also tried my hand at making a graph of the shot strings for comparison. The ES does go down by just using heavier pellets. Tomorrow morning I'll try a shot string after I lighten the hammer spring 1 turn.
Lamar
 
Upvote 0
Congratulations E-Dogg on the new gun. We can learn together.

I ran two shot strings, with a hammer adjustment on each one. I continued shooting the Crosman Premier HP 14.3 gr for each string. The first string was with the hammer adjusted 1 turn CW to reduce spring pressure. This string did start to show a slight bell curve, and the overall ES did go down. It looked to me like that was the right direction.
The second string, I turned the screw for an additional turn CW, for a total of 2 turns CW. To my surprise, it looks more like the first string I ran with no adjustment.
I'm not sure which way I should go now. I could use a little advice John, before I make another adjustment. Should I go another 1/2 turn back CCW to increase hammer pressure, or keep going CW to decrease hammer pressure more? I will ultimately be wanting to have my final tuning tor the H&N Baracuda Hunter 18.21 gr, and the Baracuda Match 21.14 gr. since those two pellets shot the best groups for me. My initial unadjusted curves with those two pellets were a little flatter with some bell shape. Attached are my results. I hope they are understandable.
Lamar

8c99f269d99b4b348b5abc35e2d74530.jpg
4a6ea4496e581d145e80f3e4eeccd8a9.jpg
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu