odd regulating on this Short, whats your Es looking like?
I finally got around to putting some time in with the Short and my chronograph. Right off the bat I the first three shots were up around 870 fps. I didn’t want it that hot, so I loosened the set screw and used the steel pins to lower the HS tension.This turned out to be a frustrating exercise. Lots of air and several magazines later, I decided to refill the gun to 200 bar, and see what it gave me. I only shot two magazines before I quit.
high = 831
low = 794.9
Es = 36.36
Sd = 9.05
This result in 24 shots is certainly far off what Keyser’s sample got. Anyone else tested their new TGAG Mutant Short with different or better results? So much for tiny holes at 9 yards.
Darryl
All Replies
Darryl first make sure you have new batteries in your chrongraph. Try and keep your gun in the same place with every shot this includes not changing the angle of the barrel. All these recommendation will help to assure you get correct results.
Darryl, it seems the adjustment on TP alignment has improved some. A complete string would be helpful to spot the issues. The Mutant is easy to maintain and not many internal parts. The trigger mechanism is the most complicated one in this gun. The issues are likely in the air path: regulator, TP and o-rings. The snug tight of HST screw is okay in my opinion. If you want to really tighten it up, you should change it to nylon-tip screw, as Dman said. The first thing I did on the gun was to change the screws (regulator and HST) to nylon-tip and lubed the cocking lever. A faulty reg can certain produce what you have observed, although the chance is rare. But it is worth checking to make sure it is functional. Show us the complete string from 220 down to 120 bars, and record the pressure drop every 10 shots. Don’t worry about the head size and weight of the pellet. Of course, make sure all the bolts are tighten and the chronograph functions properly. Good luck.
Regards,
Endo
So I should return it for a replacement? As you guys sat, first to try it with a 220 bar fill. I’ll try to get my tank refilled tomorrow.
I guess it’s always something.
Darryl
I think that Your regulator may not be regulating at all.
By you only being able to fill to say 190 bar… I don’t think you will see it in the string. By the string i saw you post it apeared a rainbow.
Thats why i ask you to post a string from 220 bar. ITs hard to troubleshoot this without seeing the Gun….
These guns Usually do really well without adjusting the Reg…. Im ocd so i sync my reg and Hst… But for you darryl you should be able to turn it up and down with the HST and not have any issues.
Ive set up over a dozen of these mutants and never had these issues your having.
James nails it!
Darryl,
I think that Your regulator may not be regulating at all.
By you only being able to fill to say 190 bar… I don’t think you will see it in the string. By the string i saw you post it apeared a rainbow.
Thats why i ask you to post a string from 220 bar. ITs hard to troubleshoot this without seeing the Gun….
These guns Usually do really well without adjusting the Reg…. Im ocd so i sync my reg and Hst… But for you darryl you should be able to turn it up and down with the HST and not have any issues.
Ive set up over a dozen of these mutants and never had these issues your having.
The HST grub screw should have a little nylon plug in front of it so it don’t bang up the threads on the adjuster.
Fill the Gunn to 220 bar and write out a full crony string down to 120 bar or so.
Exactly “D” I have one if you need it Darryl but that is all I have is one. So if dman has more then one let him send you from his supply. :whistle:
thanks for the tips, Oakie. Maybe Dman can help me out.
I need to get my air supply replenished before I can do 220 bar. How’s 190 in the interim?
Darryl
Just an FYI: The agreement was Petr has promised to warrant all sales that he has done. I’ll do the same. We are only going to make a good thing greater by managing TGAG. Most know who I am, that we are a dedicated business that gets stuff out the same day. Please, those that know us willl speak up. Those that don’t please don’t spread rumors. We have a 100% positive feedback and intend to keep it that way. Please spread the word in a POSITIVE manner.
Thank you,
Joe Brancato 602-674-5309
http://www.TopGun-AirGuns.com
The HST grub screw should have a little nylon plug in front of it so it don’t bang up the threads on the adjuster.
Fill the Gunn to 220 bar and write out a full crony string down to 120 bar or so.
Exactly “D” I have one if you need it Darryl but that is all I have is one. So if dman has more then one let him send you from his supply. :whistle:
Darryl. Where do u live??
The HST grub screw should have a little nylon plug in front of it so it don’t bang up the threads on the adjuster.
Fill the Gunn to 220 bar and write out a full crony string down to 120 bar or so.
an update. First, the barrel I have, except for the misalignment of the grub screw retaining dimple, center-punch (whatever), and that mysterious 7 o’clock dimple seems to be shooting better, and more consistent due to a change I made. I still need to do a full chronograph test. I removed the one from the “Petr sold TGAG” thread because of my new findings.
Anyway, before, the groups would go crazy, and get bigger. Now they are consistent and mostly uniform, and very much smaller, as I had expected them to be. What changed? Well, it appears the HST grub screw needs to be very tight. Not just snug. I felt I was over-tightening the screw, but it yielded results. Maybe a “Hail Mary”? Also, nice to know the gun will easily exceed 1000 fps with an HST adjustment. Right now it’s set at around 810 FPS. Much quieter, and within my needs.I’m still a bit anxious about the Es now that the gun seems to be shooting more consistently. I also checked the barrel alignment to the tp. It hasn’t moved. But with no recessed grub dimple, I’ll worry about it. Tightening that HST grub screw as I did, hmmm…I hope that really is the cure.
Darryl
HI Endo,
I have this bad habit of checking my email before most other (mundane) things of the day. Doing so means I’ve decided to share something here before I do further testing. Let me start by saying this morning I took a few shots with the Short because I had a few spare minutes before heading out. I checked the gauge and saw about 160 bar. I did not report this before but the gun makes an interesting ringing noise from the hammer strike. It builds slightly in intensity before dying away, almost a two-tone sound because of the distinct change in pitch. I’ve been trying to search for a better description. It’s like a brief crescendo sound. Anyway, since I usually started with a 200 bar fill, I was getting used to the sound. This morning I simply loaded a magazine and started shooting. Here’s the odd thing; the sound changed when the pressure dropped to about 150 bar. That was towards the end of the first magazine. Now I don’t know anything about regulators, so I won’t speculate what might be going on. I’ve sent Petr an email about the high Es numbers I’m seeing. Haven’t heard back yet. Hard to tell who’s on first with the “sales group” at TGAG Of note is that with a 200 bar fill, the first few shots are spot on, but subsequent shots open the group up. This at about 9 yards in my basement, so wind (unless I’ve had bean soup for lunch! :rofl: ) So, what I want to do is a chrony test from a fill of about 150 bar and see what I get.
btw, about the Ed barrel, some guys are finding success with Air Arms pellets. I bought several tins of the 16-grain, and the 22-grain pellets. Using the JSBs for testing of tunes.But I haven’t had range time to really compare, especially since I’ve re-tuned the gun to shoot the 18-grain pellets at around 930 fps.
on a lighter note, a polar bear has escaped from our local zoo today. Polar bears are apex predators, and will anything that moves. The zoo is on lock-down. just goes to show, it’s always something.
Darryl
Darryl, my R3 is very picky on pellet head size. I have done a lot of tests on my R3 and found out she likes 5.50-5.51 mm head only (JSB 18.1 grain). I sorted out the pellets from 5.56 mm down to 5.46 mm. The speed varies slightly but there is no significant difference in shot-to-shot variation and extreme spread with different head sizes. But I am not sure about the weight. I don’t know the effect of weight on speed variation. My R3 is so picky and the 5.50-head is difficult to find. The pellets I got from PA are 5.48 – 5.49 mm most of the time. So, I have changed the barrel in my R3 with a Listone barrel (done by Dman) (http://www.talonairgun.com/forum/viewtopic.php?f=34&t=22808&start=220). You are the last one commented in that thread. The new barrel is not pellet picky and is as accurate as LW barrel if not better. My R3 is collecting dust now. My Mutant Standard is such a great gun to shoot with. So, I have a high hope that the Listone barrel will do well in my shorty as Keyser, Oak, Greg and Dman have experienced. Unfortunately, Dman has no Listone barrel in stock and I haven’t heard back from Petr on my barrel replacement…
Glad to know you found something “unusual” in your CZ barrel… Petr (or Joe) should fix it (but who knows…). Hopefully, this is the only culprit on your issue. Although I doubt the problem on the regulator, you may want to check it out too.
Regards,
Endo
these pictures are reflective of my little camera, and it’s limitations. The ones with the blue tape attempt to show the gap created by how offset the dimple is from the transfer port on the (almost) opposite side. The photo with no tape shows the location of the grub dimple on the barrel, and how it is offset from the top center line of the breech.
the gap showing the offset:
and again:
a view with no tape. note the grub dimple (punch mark) is higher than the center line of the breech. I think the reflection on the barrel shows it best:
Hello again Endo,
While I have not done a lot with checking pellet head diameters, I can say it’s been my observation from looking at my spreadsheets (of tests with different pellet weights) is that the heavier pellets in those tests have produced shot strings that are more flat along with lower Es numbers. Same guns, different pellet weights. None of them were regulated, so I can’t speak to what you’re seeing, except that it is surprising to me.Trying to get my brain around it, that’s how I came up with the WAG about head diameter. Just a WAG.
Meanwhile, I did take the barrel back out and looked closely at the alignment of the grub-screw dimple to the transfer port, center line for center line, and the dimple is off by maybe close to fifteen degrees. I took pictures which I’ll post soon. Anyway, I made a tiny mar in the barrel’s finish to indicate a better alignment position and reinstalled the barrel. That barrel grub screw sticks up higher now, but i’ts not an issue. So, being curious, I ran off a magazine across the chronograph, and the Es was 20-plus as the fps fluctuated, then dropped away. From 200 bar down to about 150 bar, with a stop to reset the HST from (a now) 925 fps to around 810 with the a high of 813 fps and a low of 788. One magazine. I’ll contact Petr, of course.
Darryl
PS I’ll try to get a full test in tomorrow and post the results.
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helllo all,
thank you for the tips. The battery in my chronograph has been in there less than a month. Also, I checked to ensure that there is a nylon insert (?) between the HST grub screw and the HST unit. I made sure to snug it up, but not excessively. Just tight enough not to loosen itself up during my tests.
Please look at the attached images of my test results with two different pellets. Both are supposed to be 5.52 head diameters. Notice each has a start fill of 210 bar. Starting at 220 bar proved to be too high for this gun as the first few shots were well below the average setting so I reduced the fills to 210 bar. Not being very familiar with this gun I was surprised I could not get more than 30 shots at arouund the average pellet speed a9you see) before the speed started dropping off. At least I know. Now, in a non-regulated PCP I’d take the hammer spring out and cut or grind off a partial or a whole coil or more. With this setup I suppose I can back the HST off a bit more in an attempt to level out the shot string.
Please use your analytical skills to advise me as t o what you see,(and a possible cure?)