GTA
Airguns by Make and Model => Diana Airguns => Topic started by: Mr Sasquatch on January 18, 2013, 09:24:06 PM
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I need your help.
My D34 (.177) has almost 4,000 pellets through her. After the first 1000 I installed Jim Macarri’s OS kit and did a complete lube job. Initially I was using Leaper’s 4-12x40 scope with RWS one-piece mount and while the rifle was normally shooting very tight groups, once in while the POI would jump up or down in random intervals. The Leaper’s scope was sent back to the manufacturer for warranty repair at the beginning of this year and in the meantime I installed a brand new CP 4-16x 40 scopes. Soon after that I noticed that the POI is now not jumping but rather” strolling” up and down.
Here is what I mean. I shot over 23 rows of 5-shot groups, one shot per target . The scope was zeroed prior to this experiment, and the adjustment turrets were never touched after that. I used the maximum magnification of 16,x and the scope was adjusted for parallax. Shots were fired in my basement with the air temperature around 62 F, from the bench at 10 m distance. The same tin of AA Field 8.4 gr unsorted pellets was used. All shots were fired with the POA at the center of the black bull’s eye. The tagets are 0.7" in diameter (the size of a dime).
At the beginning (rows #1 and 2), the POI was almost exactly in the center of each target, however starting with row #3 the POI started "walking” upward and stayed off for rows #4,5,6 &7. Actually if rows 4 through 7 were all put on the same target, this would’ve been a very tight group. In row #8 the POI stated drifting down towards the center, overshot a little bit in row #10, but then stayed on the bull’s eye in rows #11, 12 and 13. In row #14 it stated drifting again, this time below the POA. In the middle of row #15 the drift direction reversed itself and in row #16, 17, and 18 the POI was again above the POA, only to start drifting down in row #19. It stayed put for five shots in row #20 and then dropped down in rows #21, 22 and 23. In row #23 the POI started drifting up again. The up and down drifting continued in this fashion for another 10 5-shot groups ( not shown here) before I had enough of it.
These variations from the POA are not random like one would expect if they were casued by differences in pellets If I were to plot the distance from POI to POA versus the shot number, the graph would look a sine wave. So, what the heck is going on with my Diana? Or is this the scope doing it? Any ideas?
(https://lh5.googleusercontent.com/-2ieF7bD_tng/UPnt_T_OCRI/AAAAAAAAA-w/40gv8jOT28k/s640/IMG_2405.JPG)
(https://lh5.googleusercontent.com/-dZmqHxe47kI/UPnvytO5h8I/AAAAAAAAA_Y/SncgCx5_Cs4/s512/IMG_2406.JPG)
(https://lh3.googleusercontent.com/-HGrAaLHs2dc/UPnv85EGAOI/AAAAAAAAA_g/aQ5RfvudHI8/s512/IMG_2407.JPG)
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Scope rings moving on receiver dovetail most likely cause ... or at least worth looking at ?
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If the scope isn't moving, then try cleaning your barrel. I have this problem from time to time. Cleaning the barrel usually brings my accuracy back.
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One other thing, are you resting the gun directly on the bag, or putting your hand in between the gun and bag.
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One other thing, lube the ball and detent, also check your breach seal, see if it needs shimming.
Dental floss works wonders.
Question did you ever change the piston seal, when you installed the kit, if not consider a new one.
The kits do not come with one, this I know.
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I believe there are two versions of that scope. One the earlier ones, as someone reported here, the tiny little set screws for the adjustment rings tend to come loose. Several people have remedied this with locktite and resolved their problem. This scope got kind of a bad rep for not holding zero the first couple of years. Wasn't the innards but those screws. The currently sold models are supposed to correct this.
Re-examining the second target from the bottom, that must be something in the sighting system. Even with erratic fps (as from a damaged seal) you should not get such a sort of rotating pattern. I would take off the scope and, if you have irons, shoot another target.
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Thanks for the suggestions so far.
I use Caldwell's Junior front rest and do not touch the forestock with my hands.
I have cleaned the barrel with Goo-gone about 100 shots before the test, and then run dry patches half way through the test.
The ball & detent were lubed well just before I started testing. At the same time I replaced the breach O-ring.
I replaced the original piston seal with one from JM when installing his kit. Yes, I bought an extra seal.
The stock screws are tighten and set with blue Loctite.
The scope mount screws are all tight, that I'm sure of. But is it possible that the whole dovetail mounting part is not fastened well to the tube? This I'll check tomorrow.
BTW, I tried to use iron sights too, but with my eye sight trying to hit this target at 10 m? A beer can? Yes! A dime? No way.
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On a springer you should always support your gun with your hand, no matter what kind a of rest you use.
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As Redfeather points out. Check the tiny retainer screws on the windage and elevation turret adjustments for tightness. Might check the Magnification adjustment ring screw too, while you're at it. These are tiny screws...like eyeglasses size.
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if you changed the breech seal they take time to break in! and could take up wards of a few tins of pellets to start sealing right! and another thing I would check is how consistant are the pellets you are using? have you measured them? I'd say IMO that what you are seeing is normal for that type of rifle! it isn't a target rifle! its a break barrel and a entry level gun from Diana not that that's a bad thing but IMO I myself included sometimes expect to much from things and drive myself nut's to make something perfect that just will never be! JMO :P
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Good point.
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This is only at ten yards...
Before this event, were you able to keep all shots in the black, did it always do this.
There is a lot going on when you pull the trigger, your breathing must be the same, hold and head position the same, trigger pull the same, shoulder contact the same.
If shooting in rapid succession, you are going to change the temperature with in the gun, this will affect velocity as well.
I use a standing bench, I shoot at targets that are the size of a pellet hole or at a pellet hole itself.
Seeing I have done my own tuning on this gun and have years of experience with airguns.... it also helps that the man who taught me had extreme sniper skills ( no need to get into details).
If I do my part, at 25 yards I can sink a pellet into a pellet hole ,might not be perfect but it will be in the hole.
So consider, it may not just be the glass or the gun, you may be doing something ever so small to effect the rifle.
Many will say these are not 10 meter match guns, TRUE, but if worked right with the right shooter at the helm, then they become 25 yard guns, from a standing bench.
JMHO
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Rob I'm thinking the same thing! could be shooter error? not being consistant with the hold? I agree these rifles can be tack drivers if all is working well with the rifle? :P
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Here are some things I have seen posted time to time on shifting POI:
-Check all scope related screws and reset again and loctite them.
-Gun may like a new hold position.
-Never rest a springer direct on a bag.....use your hand to support.
-The gun may like another pellet all of a sudden which means going back to that same old quest to find what works.
-The barrel may need cleaning.
-Lastly.......you may have a muzzle that needs recrowning.
Hope you find what the issue is.
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My point wasn't to bash...but to state there are a ton of variables to consider.
Sometimes it is just not ONE thing but a combination of several coming together.
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She can do rather well with the same support and hold. Here is 25 shots at 10m, the same bench, same AA pellets, but about two months ago and with the Leaper's scope.
(https://lh6.googleusercontent.com/-ro6fCrttyqs/UPseobIdsjI/AAAAAAAABAQ/iex8qPcDgtg/s512/IMG_2424.JPG?gl=US)
or at 60 ft outdoors
(https://lh3.googleusercontent.com/-Zfo13xlGsC4/UPsbYj5p7RI/AAAAAAAABAA/J03GojGWu2c/s576/IMG_2386.JPG)
What puzzles me is this regular up & down drift and almost no change in windage. If it was either the variation in pellets, hold sensitivity, bad seals, and/or shooter's error wouldn't the POI pattern be completely random?
Now, about re-crowning the muzzle... is this a DIY type of job or should it be left to professionals?
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With those shots, you need to start shooting our GTA contests.
Don't know if you golf or not, but alot of times a guy gets a new Driver or putter. He has a great honeymoon...but then starts drifting back to where he was, with a little improvement.
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Crowning problem, shotgun pattern.
Up and down, Generally seal or breach seal problem, or pellet size...inconsistent speed
Also as stated, very well could be the scope.
2 months ago, that was some sweet shooting!
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here again Rob I agree with your view usually up and down string is either bad lock up, pellets or a seal issue but so is a lose or tight hold on the gun, I've noticed when scopes go bad the shots are all over the place in a shotgun pattern! :P
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My 34 will occasionally do what yours is doing...what I found to be the problem was me being inconsistent with hold. I use a sand bag at a table and when my groups started walking for no apparent reason I had to backtrack to find what I was doing differently and it boiled down to seating position and how I addressed the target and how I was holding the gun from the front to the rear. My worst shots came when resting the front of the gun on the bag instead of my hand and from not being totally into the shooting session. Takes a Zen approach and not being distracted, mentally, for me to have a great shooting session.
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That sine wave patterns sure tweaks my interests. Sounds at first like there must be something circular involved. But it could also be a very, very slow change in shooting behavior that works its way out and then back. So hard to tell. Hope you get it sorted.
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Looked carefully at your targets, again. Noticed that most are right on vertically. That is, they are in line with the bull most of the time (with a slight shift to one side but not like a flier). It's as if your gun is shooting high, then low for a bit, then high once more. But the variance is almost steady throughout each string. My money's on the scope. You wouldn't be able to hold such consistency with a bad seal. Consider that your seal would have to be leaking consistently (as in when you zeroed the bulls), then tighten back up for a string or two for the high shots, then leak consistently once more to bring the poi back down. It could also be due to a slight change in your cheek weld. Is the eye relief comfortable with the new scope or do you have to "crawl" the stock a bit? Still, looks like something mechanical going on with that scope. As said, the CP's have been known to be spotty.
BTW, with such a tiny target (dime sized in full?) and at 16X I imagine it's not that hard to throw the poi off through slight movement. How bright is the scope at 16X?
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On a springer you should always support your gun with your hand, no matter what kind a of rest you use.
I can't totally agree to this supposition. My sight-in rest is atop a tripod with a V shaped rest with 3 inches of double layer soft egg crate foam on top. I can get a very decent sight-in with a brand new rifle on this in 5-8 shots and then start immediately to get dime sized groups at 10 yards. On a well broken in rifle and a good tune-up, with this rest, I can regularly get ragged one hole groups at 20 yards but cannot get close to this with a hand hold. Although I am a fairly good varmint killer with my ARs, I can never duplicate with my hands (the artillery hold) as well as on that soft foam rest.
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Sorry if I cover some ground that other may have already...
If this problem is happening consistently in this up and down motion and just keeps happening over and over again rythmically then it suggests something has come adrfit and is also moving rythmically, like mounts or some other mechanical device, but to repeat like it does would seem to indicate something is moving back and forth or up and down or side to side etc. Look for scrape marks in the bluing or painted surfaces in and around the scope mountings etc.
How many shots does it take to complete one whole cycle - that point at which you can see the cycle starting all over again..??
Does this happen exactly in the same manner per complete cycle - roughly the same number of shots per cycle etc..??
Definition of a "cycle" just to clarify, eg = The POI is dead on the bull, then begins to climb, topping out, then begins to fall, falls past the bull, keeps falling, bottoming out well below the bull, then begins to rise, eventually back to the bull... That I call "one cycle",, where the POI will once again begin to climb...
Can you see a pattern happening whereby you get a continual rythm..?? If the cycle is getting bigger each time or smaller each time, then it may be that it is building up to some sort of final event and may eventually result in something giving way, coming completely adrift or breaking etc. If the cycle is the same each time, then it appears there may be an answer, depending on just what really is happening... I know I am stating the obvious but all you have to do is to find that cause...
The first place to start is tightening all those screws - for-end, trigger guard (screw into the gun), scope mounts, scope rings. I've seen quite a few similar problems in grouping that have happened through loose stock screws etc...
Good luck..!!
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I had this same problems with my CP 4-16x40. After buying 3 of them two are holding up well but one of the scope has this up and down movement too. I've not documented it like you have but the up and down really rings a bell.
Now I will lock- tite the small screws on the top of the dials and the small screws on the side of the dials also. These go loose all the time with my B-26 and B-25. Lately I bought two 3-9x50 Hawks, probably put the CP's in a draw
When the scope started moving it was a slow process over 40-50 shots. After trying and blaming the mounts it dawned on me it was the scope.
No problems with the Hawk scope they have been holding up good.
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On a springer you should always support your gun with your hand, no matter what kind a of rest you use.
I can't totally agree to this supposition. My sight-in rest is atop a tripod with a V shaped rest with 3 inches of double layer soft egg crate foam on top. I can get a very decent sight-in with a brand new rifle on this in 5-8 shots and then start immediately to get dime sized groups at 10 yards. On a well broken in rifle and a good tune-up, with this rest, I can regularly get ragged one hole groups at 20 yards but cannot get close to this with a hand hold. Although I am a fairly good varmint killer with my ARs, I can never duplicate with my hands (the artillery hold) as well as on that soft foam rest.
This has been my experience as well. I can get much better groups (see pictures above) using my front rest & not touching the forestock with my hand, than with the artillery hold. Besides, how could a rifle (an inanimate object) tell the difference between human flesh and bones and, for example, a sock full of rice as long as it can move freely against the support?
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On a springer you should always support your gun with your hand, no matter what kind a of rest you use.
I can't totally agree to this supposition. My sight-in rest is atop a tripod with a V shaped rest with 3 inches of double layer soft egg crate foam on top. I can get a very decent sight-in with a brand new rifle on this in 5-8 shots and then start immediately to get dime sized groups at 10 yards. On a well broken in rifle and a good tune-up, with this rest, I can regularly get ragged one hole groups at 20 yards but cannot get close to this with a hand hold. Although I am a fairly good varmint killer with my ARs, I can never duplicate with my hands (the artillery hold) as well as on that soft foam rest.
On a springer you should always support your gun with your hand, no matter what kind a of rest you use.
That's what I was taught and it has worked for me.
If I zero a scope of a rest without my hand and then shoot off hand, POI is not the same.
Zero with my hand as support of a rest, POI stays the same off hand.
I can't totally agree to this supposition. My sight-in rest is atop a tripod with a V shaped rest with 3 inches of double layer soft egg crate foam on top. I can get a very decent sight-in with a brand new rifle on this in 5-8 shots and then start immediately to get dime sized groups at 10 yards. On a well broken in rifle and a good tune-up, with this rest, I can regularly get ragged one hole groups at 20 yards but cannot get close to this with a hand hold. Although I am a fairly good varmint killer with my ARs, I can never duplicate with my hands (the artillery hold) as well as on that soft foam rest.
This has been my experience as well. I can get much better groups (see pictures above) using my front rest & not touching the forestock with my hand, than with the artillery hold. Besides, how could a rifle (an inanimate object) tell the difference between human flesh and bones and, for example, a sock full of rice as long as it can move freely against the support?
That's what I learned and it have always worked better for me to support the gun with my hand.
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The above post came out totally wrong. :o
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On a springer you should always support your gun with your hand, no matter what kind a of rest you use.
I can't totally agree to this supposition. My sight-in rest is atop a tripod with a V shaped rest with 3 inches of double layer soft egg crate foam on top. I can get a very decent sight-in with a brand new rifle on this in 5-8 shots and then start immediately to get dime sized groups at 10 yards. On a well broken in rifle and a good tune-up, with this rest, I can regularly get ragged one hole groups at 20 yards but cannot get close to this with a hand hold. Although I am a fairly good varmint killer with my ARs, I can never duplicate with my hands (the artillery hold) as well as on that soft foam rest.
This is what it should look like.
If I zero a springer of a rest without hand support and then shoot off hand, POI is not the same.
Zero with my hand as support, POI stays the same off hand.
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If you consider the skin's ability to slide on it's muscle, and then the next layer of muscle, as the next progressive absorber, you'll see the difference between it and a bag of rice. Not to mention your clothing as another progressive layer. Rest it on your forearm, and you'll see similar effectiveness. Think of it as a 2 or 3 level progressive absorber, rather than 1 set level absorber. I will say that I do use a bag also...with a folded up towel on it, to achieve 2 levels.
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I must say, each person uses their own way to shoot.
If it works, the groups are satisfactory to you, then have it. Myself, I balance the rifle on my hand, I find this the best way for me.
It gives me extremely tight groups, but it may not work for others.
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I think that we can all agree that what works for one doesn't always work for another. I get NO difference in POI whether using my foam rubber rests and using my hand in a hunting situation. I am sure others would not find this the case. We are all built different and hold and do things differently so there will always be natural differences between us. The only thing I was trying to express is that because something works for me, it isn't up to me to tell someone else that is the way they should do it. I probably didn't express my case very well so if anyone was offended, I apologize.
I DO, however, believe that we should all keep this thought in mind when we are attempting to help someone correct a problem by trying to get them to do things 'our way'. We should always attempt to see a problem from every perspective and try our best to not be dogmatic with recommending solutions.
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The only thing I was trying to express is that because something works for me, it isn't up to me to tell someone else that is the way they should do it.
You're right.
My post, "On a springer you should always support your gun with your hand, no matter what kind a of rest you use."
It sounds like, do it or you will fail.
That is of course not the case.
It's just the way I was taught.
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Regardless of his rest, he seems to be getting a consistent variance. The POI's are as if the gun is shooting at one fps (sighting in on the bulls) and then a tad hotter (higher impacts) and then back down to the original fps. Bad seals, changes in the "fuel" mixture, etc, cannot explain that since the variance seems to be consistent across the strings. Why I opined that it is probably a sighting error and that points to the scope. Could be cheek weld but I figure, if he can hit those bulls that well, he knows a thing or three about taking a consistent cheek weld. The definitive test is to change the scope for another. Until then, it's all conjecture.
BTW, shooting off the hand and then off bags will certainly change the dynamics of the shot cycle, just as moving the hand up and down the forearm will. Springer dynamics - the eleventh circle of h3ll.
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You guys gave me several ideas to try. Thanks for your help. Basically, I'm reviewing every component in my shooting setup. One change at a time, checking for POI drifts. So far I've tried a different, softer front support, tightening those tiny screws in the scope turrets, dry parches through the barrel (again), deliberate & consistent trigger pull and the same location of the opposite thumb. So far, neither had any effect on the POI drift.
Tonight I checked the screws mounting the dovetail rail to the chamber - solid as a rock. Then I remounted the scope using loctite on some screws. I'll let it set for 24 hr and will continue my quest tomorrow.
If, after all these trials, the POI still keeps " walking", I'll replace the scope. I bought this one at Walmart with extra insurance so this should be easy.
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I also have in the past bought scopes from Wallyworld and have nothing but problems with them! so I no longer buy scopes from them and try to buy a little better quality even if their Leapers their better then the scopes from there! JMO! I will make this point you cannot skimp on an AG scope especially on a springer! :P
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Incidentally, I've had good luck shooting my spring and gas piston guns using a gel bicycle seat pad on top of my tripod for a rest that also "gives" like your hand would.
It might be something to try.
John
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Incidentally, I've had good luck shooting my spring and gas piston guns using a gel bicycle seat pad on top of my tripod for a rest that also "gives" like your hand would.
It might be something to try.
John
That, or one of those gel-filled wrist support thingies used to prevent Carpal tunnel syndrome when using keyboards.
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Incidentally, I've had good luck shooting my spring and gas piston guns using a gel bicycle seat pad on top of my tripod for a rest that also "gives" like your hand would.
It might be something to try.
John
Good call John. I've done the same thing but I didn't even think of posting it.
Edit: Thanks for the reminder too, I'll have to try using it again.
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Coming at this from a mathematics point of view, those strings are WAY to clean to be completely random. There's definitely something of a cyclical nature going on, here. To really lock that idea down, do what someone else said and run some shots with your tightened screws, etc., and count the number of shots it takes to complete a full sine cycle (up from center, down from center, and back up to center). If you get 3+ cycles within 1-2 shots of each other, that's too clean, and variance is coming from a system with a limited axis or range of movement. Probably not you, looking at your "before" shots. Those showed the type of variability that one would expect.
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I had the same problem with my 350 magnum.
I was sure that the scope was fixed rock solid on the gun, cause the mounts have a stop screw that I tied to go down one of the stop holes on the rail, and started looking at everything else. Until I had to replace the scope and found that the recoil has caused the stop screw tip to bend and needless to say the scope was shifting even though it was unnoticeable.
Take the scope off the gun and check your mounts cause it looks like you have a scope shift.
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It's things like this that really, really make me wonder why even some of the more expensive guns still have the stupid 11 mm dovetails cut into them for a scope mount. That's not a real scope mount solution. When will the companies accept that? What Crosman has recently done with even their more affordable guns - welding a weaver/picatinny rail onto the receiver - should be standard for springers IMO. At a minimum, they should be drilled and tapped for Weaver bases. I would think that drilling and tapping a receiver would be even easier and cheaper than milling a pair of grooves in the receiver.
But what do I know... ::)
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Yep, regarding the mathematical comment, these strings are not typically random. Why I suggested the scope might be doing it.
How, exactly, are you shooting your strings? What is your routine during and in between?
BTW, regarding the 11mm scope mounts, you have to understand that most of these guns, especially the better ones, are coming out of Europe. My bet is that's a popular dimension over there. I have the same issues with their sling eyes. Try finding a good sling to fit a European shot gun.
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Well, it's not so much the dimension as it is the design. It's pretty much a no-brainer to see how much more secure a weaver rail is than a milled groove. You'd think they would figure that out.
milled grooves are a relic from a gone-by era when scopes were not often seen because they were too expensive and rarely seen, and nobody expected that kind of accuracy from a .22 or an airgun.
John
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Is the elevation knob maxed out( CCW )?
That could make the scope's internals move during shooting.
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How, exactly, are you shooting your strings? What is your routine during and in between?
Here is my bench.
(https://lh5.googleusercontent.com/-fSaNuSchckY/UQBrtwbV2oI/AAAAAAAABAg/mHX7Cv6_mUc/s576/IMG_2411.JPG)
Exactly 10m from the "business end :D" of the barrel is my pellet trap and the targets. I have a lamp there to illuminate the targets, so I can see them really well and sharp through the scope.
(https://lh3.googleusercontent.com/-p03CQHeV09Q/UQBtdch9HpI/AAAAAAAABAw/UVnVIYlrSnI/s720/IMG_2410.JPG)
The front of the gun rests on Caldwell Rock Jr rest. The butt is supported on a short paint roller which I move back & forth to adjust the elevation. I shoot maybe, at most, 1 shot/minute. I take my time to aim well and make sure my eye is centered with the scope, control breathing, pull the trigger very slowly. The cheek just barely touches the stock. The rifle is practically free-floating on its front end back rests. My trigger hand thumb rests just below the safety facing forward, and only applies enough pressure to work the trigger. After each shot I check the POI through the scope before I break the barrel for the next pellet. I pick up the pellets from one tin at random -no preselection, weighing or lubing.
A first, after any break longer than 1 hr (they were usually 24 hrs) I'd start a session with 5 warm-up shots on another target to eliminate any effect of a cold gun and/or thick lube. However, I soon discovered that such warm-ups were not necessary; the gun would keep shooting to the same POI as before the break. I usually shot 3-4 rows ( 15 -20 pellets) in one sitting. If I noticed a start of a POI shift cycle I 'd continue to make sure that it was really so. When the new POI got well established I'd stop and resume the next day. The gun stayed on the bench (see photo) all the time. The temperature kept steady:60 -62 F .
Any other details I missed that may be important?
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Is the elevation knob maxed out( CCW )?
That could make the scope's internals move during shooting.
Nope. I made sure that both, elevation and windage, are more-or-less in the middle of their ranges. This scope allows approx. 5 and 3/4 turns span so the knobs are around 2-3 turns from their respective "IN" positions.
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I have remembered something similar that happened to me.
Quite some time ago, I had purchased a winchester 500x air rifle, that came with an AO scope.
I mounted the scope fine and dandy. My shots would be on, then down , then on, then high.
I chased the problem for a bit, cleaning and stripping the air rifle several times. Remounting the scope.
What I found was an irregularity in the glass on the eye piece. It would change the targets position. Mind you none of this was known to me at the time, but it presented the same problem you are having.
After I switched it up for a leapers scope, and the problem went away, that was when I took interest in finding the problem in the stock scope.
It was then I found the problem and it promptly found its way into the trash.
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OK guys received the shipping info on my gun today. It will be delivered to the gun shop Friday. I will go pick it up Saturday. I don't feel like the red headed step child anymore.
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Dockey...
What gun...a tx
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Yes Rob TX200 MKIII. Beech. Just realized I put this in the wrong Post. Brain cloud I guess.
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Congrats on the new shooter!
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I think excitement on getting a new shooter is allowed in ANY post.
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Probably pushing the wife out of bed at 6:00 am Saturday. She wants to go with me, and get some ammo for the SIG I gave her for Christmas.
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It's things like this that really, really make me wonder why even some of the more expensive guns still have the stupid 11 mm dovetails cut into them for a scope mount. That's not a real scope mount solution. When will the companies accept that? What Crosman has recently done with even their more affordable guns - welding a weaver/picatinny rail onto the receiver - should be standard for springers IMO. At a minimum, they should be drilled and tapped for Weaver bases. I would think that drilling and tapping a receiver would be even easier and cheaper than milling a pair of grooves in the receiver.
But what do I know... ::)
Most of the springers I own have that 'stupid' 11mm dovetail mount on them. I also own 2 of the Crosman rifles with the Weaver rails SOLDERED on. I can get really great, solid and stable 1 piece mounts for the dovetails that hang on solidly and reliably and are as stable as I could ever hope for them to be. NEVER had a problem with any of them. Of the 2 Crosmans, I have never been able to find a really good stable 1 piece mount for them and consequently have to use Weaver 2 piece mounts which I have found loosen and begin shifting with unexpected regularity. I have tried several different sets of so-called premium Weaver rings and have never been altogether satisfied with them.
I'll take good old fashioned dovetails any day!!!
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It's things like this that really, really make me wonder why even some of the more expensive guns still have the stupid 11 mm dovetails cut into them for a scope mount. That's not a real scope mount solution. When will the companies accept that? What Crosman has recently done with even their more affordable guns - welding a weaver/picatinny rail onto the receiver - should be standard for springers IMO. At a minimum, they should be drilled and tapped for Weaver bases. I would think that drilling and tapping a receiver would be even easier and cheaper than milling a pair of grooves in the receiver.
But what do I know... ::)
Most of the springers I own have that 'stupid' 11mm dovetail mount on them. I also own 2 of the Crosman rifles with the Weaver rails SOLDERED on. I can get really great, solid and stable 1 piece mounts for the dovetails that hang on solidly and reliably and are as stable as I could ever hope for them to be. NEVER had a problem with any of them. Of the 2 Crosmans, I have never been able to find a really good stable 1 piece mount for them and consequently have to use Weaver 2 piece mounts which I have found loosen and begin shifting with unexpected regularity. I have tried several different sets of so-called premium Weaver rings and have never been altogether satisfied with them.
I'll take good old fashioned dovetails any day!!!
Seriously? I can find weaver rings all day long that will stand up to anything. Now, finding adustable rings to compensate for barrel droop? That may be tough. But again it's a solution for a problem that shouldn't exist in the first place.
John
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if you changed the breech seal they take time to break in! and could take up wards of a few tins of pellets to start sealing right! and another thing I would check is how consistant are the pellets you are using? have you measured them? I'd say IMO that what you are seeing is normal for that type of rifle! it isn't a target rifle! its a break barrel and a entry level gun from Diana not that that's a bad thing but IMO I myself included sometimes expect to much from things and drive myself nut's to make something perfect that just will never be! JMO :P
Sorry to pull up an old thread but I like to search the site first when I have a problem. I'm trying to fix a breech seal problem on my air hawk and came across this comment. Should I expect my new seal to leak for a few tins before the leak goes away? I'm currently working through additional stock shims and adding coils of dental floss without much luck and the idea that it may not seal for a while has me wondering. thanks john
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What makes you think the breach seal is leaking
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A small piece of tissue paper laid over the breech flies about 18 inches straight up when the gun is fired. Is there a right way to install a breech seal?
Here's where I am:
The air hawk came with a factory installed brass breech seal shim. I have an old barrel (long twisted story) so I took the shim from that barrel and installed it along with the original shim. Still leaking. Added two coils of floss between the two shims, still leaking. increased to four coils of floss between the shims, still leaking.
I've inspected the mating surface for the seal on the end of the compression tube, everything looks normal......
thanks
John
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I had a problem like that before too.
I tossed the shims, used teflon tape, kept wrapping it in the groove until desired thickness was achieved.
Problem with the shims is, if the seal does not get squeezed against the sides of the recess, it will allow air to bypass.
If the airhawk is really that similar to the 34, then an oring from the parts department at say home depot or lowes will do. I just buy the variety pack. They seal real good.
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if you changed the breech seal they take time to break in! and could take up wards of a few tins of pellets to start sealing right! and another thing I would check is how consistant are the pellets you are using? have you measured them? I'd say IMO that what you are seeing is normal for that type of rifle! it isn't a target rifle! its a break barrel and a entry level gun from Diana not that that's a bad thing but IMO I myself included sometimes expect to much from things and drive myself nut's to make something perfect that just will never be! JMO :P
Sorry to pull up an old thread but I like to search the site first when I have a problem. I'm trying to fix a breech seal problem on my air hawk and came across this comment. Should I expect my new seal to leak for a few tins before the leak goes away? I'm currently working through additional stock shims and adding coils of dental floss without much luck and the idea that it may not seal for a while has me wondering. thanks john
I do that too and am investigating my breech seal fitment which seems flush. I've read it should stick out and the rifle shoots high with a scope. I've also read there should be metal to metal contact. Seems contradictory.
Anyway, people will see this thread if they do what i did, search function. Seems resolution was never stated (unless there was another thread started). Makes me wonder if a scope replacement fixed the issue (pics are gone, but not hard to imagine understanding the problem), or did the rifle get sold, yadda yadda yadda.
I thought I might just add one other possibility that came to mind. The barrel pivot. If not cocked consistently maybe the "shift" is there?
Anyway, interesting thread.
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On a springer you should always support your gun with your hand, no matter what kind a of rest you use.
Not necessarily. I have / had several springers that shot to the same poa, n matter if they were directly on the bag, or, supported by my hand, with no change in group size.
My RWS48 was like that, and my Diana k98 is like that. So was my xs25 / RWS 34 clone. It depends alot on the weight of the gun, and the tune/ how smoothly it shoots.
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... am investigating my breech seal fitment which seems flush. I've read it should stick out and the rifle shoots high with a scope. I've also read there should be metal to metal contact. Seems contradictory.
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Not really contradictory. An o-ring breech seal should stand a little proud of the machined breech face. Opinions vary but IMO seal should be 0.010"-0.015" above flush. When the breech is closed the o-ring is squashed until there is a metal-to-metal contact on the breech surfaces. This is a SOLID repeatable position and will provide minimal to zero air leakage (properly squashed/loaded o-ring) and optimum shot consistency.
If the o-ring is flush or below flush the breech position is still metal-to-metal solid but there is air leakage. Barrel position will be consistent but velocity will NOT be consistent and accuracy will suffer.
If the o-ring (or ANY type of breech seal) is too proud then the lockup position will depend only on the squash of the o-ring. That will VARY over time and barrel position will wander. Air leakage may be zero but the variable barrel position can cause vertical stringing (poor shot consistency) depending on how you close the barrel. Been there & done that with too fat o-rings that caused more problems than they solved.
If your rifle is shooting high a fat o-ring may seem to solve the problem of barrel rise (opposite of barrel droop). It can for a short time but it won't last.
I was still learning about springers when I posted this...
www.amazon.com/gp/customer-reviews/R3LBM8105Z0SAF
Basically a clone of your rifle in a different stock.
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The contradiction I was referring to is that if what I'd seen was true about needing metal to metal contact then it would seem more oring compression shouldn't effect droop.
At least that was my thought process.
Nice referral on the link ;)
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The objective is - all the factors considered, consistency.
Rifle - chronograph; if FPS is 'normal' and ES is up to 4%, you should have enough consistency.
Pellet - with HN FTT and/or JSB exact you should have enough consistency
Scope - good mount, good brand, good warranty policy; don't abuse it = keep it within the comfort zone (when zeroing, max of 1 turn from the optical center for both turrets); if needed, bend the barrel.
Shooter - find how to hold and rest (always softly); do a good trigger job (always squeeze smoothly); be repeatable
Troubleshooting - If rifle and pellet are ok, I always suspect if the scope is - still - holding zero (for this rifle).
Scope test - optical centering (mirror); about 3 or 4 shots just to have the recoils..; mirror - is the scope still centered? If not, the scope don't resist to the recoils of - this - gun; maybe it's still ok for a PCP or .22 LR.
To enlarge the scope lifespan holding zero, try a dampening mount - ZR and/or DM Sportsmatch.
If you are not competing, find what groups size are 'enough' to your needs and to each distance. This is the main shortcut to enjoy.