Author Topic: Hammerli Pneuma Elite 10 (Read 61875 times))

darryl · « **Reply #20 on:** November 30, 2011, 09:03:42 PM »

OK, I tore it down again after running it over the chrony. Very wild and inconsistent: FPS 800+, then 525, then 750 FPS?! I took the hammer out, then removed the hammer screw. I was surprised to find that the threads on the screw were flattened on two sides. Well that explained it to me. The screw was not allowing the spring to hold a set tension. So if those threads are bad, then I figure the threads in the hammer are bad too. So I call UMAREX to order a new hammer and hammer screw. I ask if it can be covered under warranty. UMAREX says to send the rifle (I'd pay shipping both ways). I ask why I can't just send the bad parts back for warranty. I'm told I'll get a call back in a few minutes unless I want to be put on hold. I go with "call me back". That's been over two hours now, and UMAREX is closed for the day. That may be good for me. Meanwhile, that little #60 o-ring looked just fine when I checked it.

coax · « **Reply #21 on:** November 30, 2011, 10:21:16 PM »

Mine has the phillip screw you speak of. It is for the front sight. There is only one grub screw under it for the barrel. My magazines look like the one on the left of your picture. With the cost of tooling, I wonder what drove the change of magazine cast. Do both types shoot equally?

Near 300 fps velocity swings..geez? Air has to be escaping somewhere. I'm pretty sure mine aren't that bad, but I'll check when I get the chance (new chrony came in today).

If you're talking about the hammer screw adjustment, I think some others have posted elsewhere that at least one side was flat, because the manufacturer really doesn't want the tension to be changed (?).

For what it's worth, my rifle didn't do so well with a 200 BAR fill either. It shot better with heavy pellets starting at 175 BAR.

rsterne · « **Reply #22 on:** November 30, 2011, 11:09:16 PM »

I have heard that some adjusting screws were "squared off" to prevent them being moved.....

Bob

darryl · « **Reply #23 on:** November 30, 2011, 11:16:03 PM »

Man, coax. I'd completely forgotten about the stock sight. It came off right away. CRS is a terrible thing to have.

The magazines seem to perform equally. No real accuracy advantage with either type. No problems indexing the next shot. Still odd how one is just so slightly more narrow.

That's interesting to read about the hammer spring screw. It also explains why it was so hard to turn when I first got it. I posted at the time that it was nearly impossible to turn. I was told I'd have to take it apart to see what the problem was. So I guess UMAREX will tell me to get lost now since what I'm seeing is normal. If so then I'll be hard pressed to find a leak now. I don't feel any air coming from anywhere since I put the little o-ring in. I thought that would cure the inconsistent FPS, and was really let down that it didn't. I'm open to suggestions. Incredible.

Hi Bob,
I guess I've got one of those squared off screws. So who has a Rapier for sale?

Stefan · « **Reply #24 on:** December 01, 2011, 01:59:10 AM »

did you change barrel o rings to -011?

rsterne · « **Reply #25 on:** December 01, 2011, 01:25:19 PM »

With that size velocity swings and no major air leaks I can only think of two possibilities.... The hammer hanging up on something (most likely the sear).... or a piece of dirt floating around in the valve (or elsewhere) causing an erratic blockage.... My vote is on the hammer.... Is the velocity lower if you squeeze the trigger VERY slowly and higher if you YANK it?.... If so, you definitely have a sear/hammer interference problem.... Is the overtravel adjusted too close and causing the sear to drag sometimes? (assuming it's adjustable)....

Bob

eddielee70 · « **Reply #26 on:** December 01, 2011, 04:16:41 PM »

beside the velocity difference. what pellets are you using? on facebook, they recommend these 4 type of pellets. I get better and better results with AA 13.4 g, H&N ftt 5.53mm, and top is 18.1 JSB.

darryl · « **Reply #27 on:** December 01, 2011, 06:07:19 PM »

Just back on to catch up.
Stephan, honestly I'll have to look at converting your -011. I did not see a cross-reference on the o-ring packages I looked at. The standard #11 O-ring I could slip on my little finger, so I know that's not correct. But I detect no air around the receiver, and no blow-back.

Bob, don't scare me. I'll check, but I can tell you that I don't yank the trigger as a matter of practice. It might be an interesting test Since I have the rifle apart I can look at the internals to see what I can see. If you are referring to the first stage of the trigger when you say overtravel, I still have some travel in it. But why would this condition suddenly happen? You've seen my spread sheets. Pretty consistent until now.

Eddie, I've been using mainly the JSB 18.1 grain Jumbo Heavies, but also test with the H&N FTT 5.53 pellets. Haven't tried the others mentioned on that page. This rifle started out with accuracy issues where grouping only tightened up when filling only to 145 bar. That is so completely outside of acceptable for me. Such a low charge means only a few shots in this air hog. I'm glad I left it alone today. It's been less fun. Need a fresh perspective.

hope blooms eternal.

coax · « **Reply #28 on:** December 01, 2011, 07:17:50 PM »

Okay, I ran a 30 shot string from 200 BAR to 100 BAR (that's what it took) and it's interesting;
1. 893 2. 894 3. 898 4. 905 5. 906 6. 910 7. 911 8. 915 9. 922 (high) 10. 913 11. 913 12. 912 13. 915 14. 907 15. 903 16. 899 17. 895 18. 889 19. 883 20. 880 21. 875 22. 868 23. 861 24. 855 25. 847 26. 839 27. 833 28. 824 29. 814 30. 808 (low) High 922 Low 808 AVG 882 ES 114 SD 33 18.1gr JSB .22 CAL

My peak velocity occurs closer to the front end of the fill than most. Peak velocity is at 173 BAR. The rifle is stock but velocity is like the hammer spring has been adjusted. I only have 18 shots within 96% of peak velocity. It is using 3.33 bar per shot.

darryl · « **Reply #29 on:** December 01, 2011, 08:28:51 PM »

Coax Your numbers look very similar to a sheet I have except I have two turns out on the hammer adjustment. Maybe try a lower start fill pressure if you're not going to adjust your spring tension; maybe 190 bar or 185 bar. I know. Just an excuse to buy more pellets!

Bob told me there is a spring spacer (velocity adjustment washer in Pneuma-speak) inside the hammer. It puts tension on the spring, and so may explain your numbers.I removed this spacer, and had pretty good results UNTIL I didn't. I think the advantage of removing that spacer might be in that you can fine-tune a bit better because you gain in a bit of tension adjustment.

Also, if you (or anyone) want the PDF of the drawing and parts list, email me and I'll send you a copy. Andrew of UMAREX had to send me one so we could speak the same reference language. I'm ordering a new hammer, and "velocity adjustment screw" plus a new barrel band (cleat) -going back to two, and assorted o-rings (barrel o-rings too). Oh, the drawing is for the single-shot version. I've asked for one of the 10-shot model

Can someone speak to me about the pin o-ring? It's on the drawing as part number 80. I haven't laid eyes on it yet. I'll go look now. Might be the cause of my velocity problem.
darryl

coax · « **Reply #30 on:** December 01, 2011, 09:14:37 PM »

I was using lower fill pressures after my initial testing. I hadn't chronied a 30 shot string before my old chrony broke (it was 14 or so years old). If you look past shot 20, you'll see the velocities go south in a hurry, which explains some of the vertical stringing. However, some of my best groups came when the velocity was falling off horribly. After shot 18, the rest of the shots are outside of 96% of peak velocity. I'll shoot some groups at the higher fill at 50 yds. when the weather breaks here and see what happens. As I stated before, the next groups at 50 will be with only the forward barrel band, and if needed, no barrel bands. Did you happen to find out how much a new barrel was, by chance?

rsterne · « **Reply #31 on:** December 01, 2011, 10:03:45 PM »

By "overtravel" I mean how far the trigger can move after it releases the sear.... I haven't had a Hatsan trigger apart.... but some triggers I've seen can be adjusted so that the sear won't move down enough to clear the hammer.... The trigger on my DAQ must be pulled with "follow through" or the gun loses about 50 fps.... DAQ actually warns you about that on his website.... Squeeze it slowly it releases but obviously drags on the hammer.... You literally have to "pull" the trigger to get full power.... I'll be working on that....

Bob

darryl · « **Reply #32 on:** December 01, 2011, 10:25:29 PM »

coax, I've asked for a price on the barrel. I'll let you know. I also ordered another cleat (barrel band) to replace the one I modified (with a hack saw). Also, I checked my rifle and the "firing pin" on this model does not have an o-ring on the end of it.

As for the uncontrolled FPS swings, I'll have to wait until my new parts come in. I'll be curious to see if the hammer-adjustment screw has flattened threads on it.
I'll also have to wait to test the over-travel too. I'm not used to having to keep squeezing once the shot if off. Maybe it's my technique?

rsterne · « **Reply #33 on:** December 01, 2011, 10:29:13 PM »

I'm not used to it either.... but a trigger that breaks cleanly wll normally move out of the way of the sear/hammer just from the force applied when it breaks (the DAQ being the exception).... If you adjust a Disco or 22XX hammer with too little overtravel you will get velocity symptoms exactly as you describe....

Bob

gene_sc · « **Reply #34 on:** December 01, 2011, 10:33:36 PM »

Darryl, Bob is right about the sear and hammer. Also about a piece of dirt floating around. I would suggest checking it out. Prolly allot cheaper than new barrel. And with your erratic fps you will never shoot straight..

Barrels don't cause fps problems like you discribe.

coax · « **Reply #35 on:** December 01, 2011, 11:08:48 PM »

Interesting point about the trigger squeeze follow thru, I might have to pay attention to this rifle on that. When I did that shot string I wasn't concerned with accuracy and was pulling the trigger quickly. I was actually rather suprised at the curve up to shot 18, since what I had seen on paper at 50yds would say otherwise. Good possible issue I would have never thought about. Thanks.

rsterne · « **Reply #36 on:** December 02, 2011, 12:42:05 AM »

A 4% variation in velocity is only about 1/4" in POI at 50 yards with pellets having a good BC at your velocities....

Bob

Stefan · « **Reply #37 on:** December 02, 2011, 02:12:19 AM »

attachments
10 shot EVP
O ring size chart
mine strings with JSB 18.1 and CPUM with 1.75 CCW turn from 200 bar down

coax · « **Reply #38 on:** December 02, 2011, 12:13:18 PM »

Quote from: rsterne on December 02, 2011, 12:42:05 AM

A 4% variation in velocity is only about 1/4" in POI at 50 yards with pellets having a good BC at your velocities....

Bob

Bob, that's why I'm looking at that range or better cuz I would like to be able to shoot out further than 50yds, if I can ever get it shooting the way I want.

Stefan, your curve for the JSB 18.1 is nice. So, that is the stock spring with a few links cut off or what?

rsterne · « **Reply #39 on:** December 02, 2011, 01:40:34 PM »

I agree about the curve with the 18.a gr. JSB and the "new" spring.... although I'd throw out the first 10 shots and be happy with the 30 averaging about 31 FPE within 5% of the peak velocity.... I think the best I did was 30 shots within 7% with the AT44 I worked on....

Bob

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Hammerli Pneuma Elite 10

Author Topic: Hammerli Pneuma Elite 10 (Read 61875 times))