Webley Osprey ST weird flyers

[hwtyger]

Always had some issues with 1 of my Osprey STs.
First shots sometimes are way off. Like 1 or 2 cm at 6 yrds. I know I dont shoot full score each card but thát far off at so close a distance...
Theyre not off in the same direction.
Im still looking for the cause.
Its either me, cause I do find the Osprey to be very hold sensitive or its an issue I havent thought of yet. If its me you'd expect me to have it with my other rifles as well,(MK3 ST and Walther LG55) which I dont. My other Osprey ST also doesnt seem to have this issue.
Im using regular target stance; top of hand underneath the stock. Thumbup shootinghand position. Tried and tested various variations, but this seems most accurate.

What its nót:
- all bolts are loctited so nothing is loose
- no barrelcrown issue; as after a few shots it seems to settle and I regularly dó shoot full score or amazing groups with it
- nothing is worn internally as its all new
- tried cleaning barrel, made no difference (wasnt dirty anyway)
- theres no smoke, slowburn or dieseling
In case of tap alignment, youd expect issues all the time.
Its a dream to shoot.

I use JSB Exact 4.51 cause I use it in all. Its easiest and it seems to do ok in it.
I shoot indoors, so temperatures never go below 18.5C in coldest winter. They may rise in the heat of summer. But few days ago, temperatures were nothing special and stíll shots way off

Could it be a piston seal thats either too tight or too sloppy that needs a few warming up shots?

Other ideas?

[Thegreg]

It might sound obvious but is the barrel still Loctited securely to the action? I’ve known quite a few people who genuinely thought the Osprey had an interchangeable barrel (because theirs unscrewed), when what had actually happened was it had worked loose from the meagre application of Loctite at the Webley factory.

It’s unlikely but worth checking to see if it feels solid.

Cheers
Greg

[johnbaz]

There's not a heck of a lot of threads actually holding the barrel in place on the sidelever Webleys actually!!




John..

[hwtyger]

With a loose barrel you'd expect the problem to be there all the time. Which it isnt. It seems more of a 'warming-up'issue.
Ive seen this on rimfires, with significant fouling of the barrel right behind the chamber.
Dont know if this can be an issue on airguns as well.
Maybe taploaders create different fouling than for instance bb?

But thnx for thinking along

[Mr. Gen]

is the tap nipping the pellets? try using a probe to seat them.....

[Geezer]

Could it be a piston seal thats either too tight or too sloppy that needs a few warming up shots?

It does sound like that may be it.

[Shed tuner]

easy way to see if it's powerplant or aligment.. shoot your first few shots (at your target) over a chrono.

See if the wayward shots correlate to lower or higher than normal velocities. If the velocity is fine, then it's probably a mechanical alignment (or a shooter) problem

[hwtyger]

Tap itself isnt clipping the pellets. They drop in deep by themselves. No need for seating but tnx.
Will try a chrono

[trajectory]

Sounds a strange issue & one to which I don't know the answer.

Since the first shots impact away rom the point of aim in a random fashion does this suggest it might not be a power consistency issue? Wouldn't a small varriation in power just produce a degree of vertical stringing? A large degree of varriation might not stabilize the pellet & give varrying points of impact but wouldnt that be discernible in use. A small varriation in power might give rise go vertical stringing but at 6 yards I think it would be fractions of an inch. As I say, don't know thw answer but the results of ghe first few shots of a chronograph might be interesting. It does sound like something is settling down after a few shots...

[series2a]

Same problem tried everything. Did my head in. Sold in the end It was as new so wasn’t a wear issue, also sounded like a Russian tank engine starting up. Nice looking but odd concept obviously didn’t sell well so probably there’s your answer.

[averageplinker]

If it is not the piston seal could it be a trigger issue? Perhaps solidified grease make the trigger awkward/sticky until a few shots loosen it up?
Rich.

[bill57]

Is the plastic loading tap lever in perfect condition and completely tight? We tend to think of pellet clipping as being a side-to-side issue, but if the tap lever has any play at all then you can get variation in tap closure which will cause up-down clipping.

As you say, clipping would be more likely to cause inaccuracy with every shot, but this is only true of lateral clipping. Variations in tap closure could be much more random. Shoot pellets into a rolled up towel at twenty yards and examine them, you'll soon find out if they're clipping.

[hwtyger]

Ill look at the tap, thnx.
Dont think its a problem related to the design of the Osprey itself, as my other Osprey doesnt have this issue, andmy Tracker, which has similar design doesnt have it either. (nor do my MK3s with also taploader design). I also doubt Webley wouldve picked a faulty one for their museum collection.
Wish I could give Steve P an email and ask if he knows... He knew a lot about the Webleys as they were at the same place..
Maybe its easiest to rule out myself first. If it dóenst have these issues when I shoot rested, than its me after all

[bill57]

Always, always suspect the tap in an Osprey. When set up well they're really accurate guns and not prone to fliers, but the tap is the weak point. The moulded plastic lever controls the closure of the tap, and has to be a perfect tight fit in the recess in the metal tap body. Any slop at at all and you're in trouble.

I have always found JSB to be too loose a fit for an Osprey, but RWS Superdome (.177) perform very well. Might be worth a try?

[Thegreg]

Just following on from Bill's point about the alignment of the tap locating by the moulded plastic lever..

Also check the fit of the stock to make sure that the lever doesn't contact the top edge of stock in the closed position. I have had this issue before more than once.

I have an old Tracker where the plastic lever is so worn/chewed that the lever rests on the stock when it's closed!

With all the above said I'd still concur that tap alignment probably isn't your issue, otherwise you'd likely have consistent inaccuracy, but it doesn't hurt to check.

Cheers
Greg