What the heck is going on with my Diana?

[David.Soliman]

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.

[limbwalker]

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... 

[RedFeather]

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.

[limbwalker]

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

[BenjiHunter]

Is the elevation knob maxed out( CCW )?
That could make the scope's internals move during shooting.

[Mr Sasquatch]

How, exactly, are you shooting your strings?  What is your routine during and in between?

Here is my bench.


Exactly 10m from the "business end  " 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.



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?

[Mr Sasquatch]

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.

[thekid]

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.

[Dockey 454]

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.

[thekid]

Dockey...
What gun...a tx

[Dockey 454]

Yes Rob  TX200 MKIII. Beech. Just realized I put this in the wrong Post. Brain cloud I guess.

[thekid]

Congrats on the new shooter!

[jusanothajoe]

I think excitement on getting a new shooter is allowed in ANY post.

[Dockey 454]

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.

[pappa]

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!!!

[limbwalker]

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

[jfrey]

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

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

[thekid]

What makes you think the breach seal is leaking

[jfrey]

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

[thekid]

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.