Can a good lube and tophat adjustment do this to an SS?
So, after getting some lowish velocities from my SS, I decided to really lube it up well with a different type of lubricant and readjust my tophat. I was shooting around 825 fps with .22 Superdomes prior to starting, with a power wheel setting of about 5-9. After lubricating the gun, but prior to adjusting the tophat, I fired a few shots, and was getting in the 840’s, with 844 being my fastest. I figured that would happen with better grease, and to be honest, I told myself if I could hit 850 fps I would be happy. Next, I began to adjust the tophat. I started at .085, and I adjusted it up to about .090. With this, I saw a 7 – 10 fps drop, to about 835 fps average over 4 or 5 shots. Just to be sure, I adjusted the tophat to .092, and I dropped to 827 average. So, I decided to move back the other way, and I set my tophat at .087. This produced shots in the 840’s again, and I figured that I had hit what was probably going to be the sweet spot. By now I had shot about 20 shots, so I filled the tank up to 2800 psi and took a few more shots, and that is when things got weird. My first shot was 800, which surprised me. Then I got 771, 778, and 784. Needless to say, I was disappointed. But then the next shot hit 865! Figuring this was a fluke, I shot again, and hit 864. And then after that, 875! Since then, these pellets have been shooting between 875 and 890, or at around 24 ft/lbs. So, I figured I would try my luck with Predators, and hit 850 fps (25 ft/lbs) fairly consistently. These were shooting around 800 fps before. After that, I tried Kodiaks, which had been going around 700 fps before, and hit 788 fps, for a whopping 29 ft/lbs!
At this point, I became very skeptical, thinking that there was just no way I was churning out that much energy. So, I changed the battery in my chrony, figuring maybe it was the cause of inflated readings. Nope. Still got the same velocity readings with all 3 pellets. And after I switched it back, same thing – same velocities with all 3 pellets. I shot it a few times and just listened to it. It isn’t noticeably louder than before, so I don’t think it is using any more air than before, either. So, I shot it from a little further back from the front of the chrony (about 8 inches or so) in case that was affecting things. Nope – same speeds. So, I can only come to two conclusions. Either my chrony is screwed up, or I am getting abnormally high speeds for a gun with a 12 inch barrel. Because I don’t want to believe my chrony is shot, and because I flat out CAN’T believe that I have an SS capable of creating almost 30 ft./lbs of energy, I am coming to you guys. Anyone know what is happening here? Is this common? Is the gun just getting broken in? It is only a few months old. If not, can anyone tell me why this might be happening?
Thanks in advance for the help,
Chris
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Viewing 14 replies - 1 through 14 (of 14 total)
Well first, buddy; I read what you went through\with and that’s all needed. As panning down I saw several EXPERIENCED Air Force users responding to you & did not read them.
My TSS came stock @ 6.8 out to the end of my Top Hat. I got pretty damn good results @ 3.9 on the power dial!. Then knobed the TH up to 7.6 With alot of excess loss of air in comparison to velocity (and fpe as well of course).Tweeked down to7.2. Now even .95 (not even 1.) on the powerdial gives immpressive resylts up to 20 yards!. I usually shoot 32+ grain @ a power setting of 11+. Man, It F’n kills ASS! With that sett, I’m doin well over 1050 fps with 32 grain = 50+ fpe! These guys (some of’em) can direct ya to tweaking it damn FINE-POWER-plus…. I could, but I’m tired now…. ➡
I think that might be the breech Orings….Lots of guys won’t put anything on the hammer..They say it works better dry. I have an odd hammer…
Doesn’t everyone? I thought lubing the hammer with silicon grease was in the AirForce manual as you don’t want anything else getting on the seals???
Can you upload somewhere that excel file please?
Thanks!
I lubed my hammer with silicon grease and the fps became consistant..gun now shoots quarter size group at 65yds…Before lube I couldn’t shoot a 2″ group and fps differential was as much as 100 fps. I use silicon grease on my hammer….
Never heard of a PCP dieseling. Especially if you lube the hammer and the bore it rides in. If you put a bit in the breech block, would it diesel?
You want a dry film lube in the bore, or nothing at all. The hammer on most has delrin ends on it, which is slick plastic. I use a dry teflon lube. It dries white in a real thin layer.
A lot of PCPs have a very erratic upslope when overcharged. Your first shots will be slow and all over. Then, all of a sudden, it hits the perfect line. Why? I don’t really know, but I’ve experienced it often. If you plot your data in Excel, it starts to show some real interesting things.
Here’s a plot from my TSS, testing a Homemade Delrin hammer, overfilled, and shooting down to the sweet spot:
That sweet spot will move left/right, or up/down depending on a lot of variables, like pressure, hammer weight, hammer spring, valve size, valve spring, and a lot of other shit, including hammer velocity. If your hammer is sliding along in a tube of gooey grease, it won’t hit the valve hard, nor repeatably.
Hope this helps a bit. I’m always on the quest for improvement, and rarely gaining… But, damn, it’s fun!
>>>Edit: by the way, I dumped 20 shots between 10 and 11, and another 20 shots between 20 and 21. These were simply dry fires.
I could be mistaken, but 2800psi might be too much of a fill. I’m an HPA newb, but I recall seeing that too much air causes the initial shots to go low in FPS due to valve lock, and then the FPS rises as the tank’s psi levels get in balance with the valve’s counter-pressure.
Try a string at 2700 psi and see what happens.
As far as the white lithium is concerned, I don’t know how “corrosive” it is to rubber… it’s used on cars, boats, trailers, etc., but given that the AF guns only use a few cheapo O-rings that are relatively easy to replace, it might be worth looking at. What’s the hassle of an O-ring replacement once a year if the White Lithium increases performance? Chances are that a lot of us are replacing O-rings yearly anyway simply because we feel it’s necessary… If the WL provides a better seal than silicone, it should be considered, IMHO. If there’s any major drawbacks besides O-ring degradation, I’d be interested in hearing about it.
white lithium is petroleum based, stick you nose in the tube and smell, do a search on it, and use at your own risk
On the can, it mentions that it is ideal for metal to metal lubrication where heat due to friction may build up. If I am reading the MSDS sheet that you posted correctly, it seems that it is flammable only because of the aerosol, which evaporates. I have some white lithium grease in a tube as well, and it says nothing about flammability on there, and it does mention that it is good for areas of high friction. So, I think the spray only is flammable because of the aerosol. As far as attracting crud, is the silicone oil better?
Thanks for your help,
Chris
looks like you should not shoot that thing in till you clean it!
it is definitely flammable, take a look here,
Thanks,
Chris
I think white lithium is combustible, and your increase in velocity is probably from a slight dieseling, how dose that stuff smell?
being that it is a grease it will definitely attract dirt, dust, gunk and anything else that will find it’s way in there
I used white lithium spray to lubricate it with. I read the label, and saw nothing about it being corrosive to o-rings or attracting moisture, so I thought I would give it a try. It is a little thick if you put on too much, but I just gave it a shot inside the frame and on the hammer. I tried using some silicon spray stuff that dried completely dry, but it seemed that it was still rubbing a little, which was why I went to the white lithium. Why would this not be good for my gun? Does it attract dust and gunk more than the silicon lubes?
Thanks,
Chris
what did you lube it with, it sounded like you used grease? if so this is bad and probably is causing it. you should clean everything spotless and shoot some good silicon spray down the inside of the frame, let it dry and then check your numbers
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