Webley Osprey ST weird flyers

[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

[hwtyger]

Tap doesnt touch the stock afaik.
Yeah, thought about different pellets. Only use JSBscause they do well in 95% of the guns, incl this one but never tested other pellets.
Its also easiest to remember if you use same pellet in all these
Maybe 4.51 is too small a headsize aswell? I started with this headsize cause my Diana 31 Pro prefers it. Actually never looked back. But most seem to use 4.52 or 4.53

[Dutch]

Interesting case indeed.The fact that it gets more consistent after warm up is quite a puzzle, sounds like a diesel engine . The type of grease used could also be a factor (more fluid when warmer or stirred). With a bit of structured analysis you could eliminate the factors involved (human, pellet, mechanism, grease) step by step. Strap the gun down and take the shots through chrono. Round two (after cooling down) Inspect the pellets & clean barrel before taking the shots. Still no consistency from the start, open it up clean the seal, relube, degrease inside of the tube & smooth up with wire wool, check for inconsistencies. Most likely suspect I can think of is indeed the warming of the piston seal and its interaction with the grease & inconsistencies in the tube. Maybe in combination it behaves in this fashion.

[hwtyger]

Im very pleased to inform you that the problem probably is my own sorry ass
I tried it “ semi rested” just now ( very primitive; rested on a basket with on top of that a pack of target cards its all I have; I never shoot rested.
Anyway even with this primitive hold ( couldnt hold the gun as still as I wanted) the shots still were touching or overlapping so no 1-2 cm weird flyers.
After few shots I found a more stable position and groups really started to tighten up.
Tried 4.52 instead of 4.51 but group only opened up. So that sure wasnt an improvement.
Than tried ( very old batch of) FTT which gave very promising very accurate results.
I remember my FAC Tomahawk kept giving flyers with jsb. It didnt like ftt or baracuda so I thought that was the best I could get out of it. Until I tried jsb heavy and flyers were gone.
So maybe pellets are párt of the issue.
Ill do some further testing.
Tap is tight barrel is too. Only thing that has some play is the frontsight holder. But as seen today it can perfectly shoot 3 pellets into a hole size of a 5.5mm so dont think that has much effect.
Wouldnt know how to solve it anyway; bolt is already loctited afaik