Finnfire Mounting Problems

[bryn]

I have a original Sako Finnfire rimfire which I have tried mounting 2 different scopes (Meopta, Hawke) on optilock mounts and some Sports match and on all occasions and combinations I have run out of elevation on the scope in that the point of impact is below the point of aim.
Other than chocking the rear ring/mount which I am loathed to do or fitting an MOA picatinny rail, I am hoping someone has experienced something similar and has a solution.

Thanks

bryn

 

[spandit]

Bent barrel? What range are you zeroing at? Shimming a rear mount isn't difficult with bits of drinks can cut into strips

 

[Oracle]

Burris Signature Zee rings - they include dedicated +/- protective shim inserts for front and back rings. Once the scope reticle is optically centred you fit shims as an opposing pair within both sets of rings to save having to make gross elevation adjustments using the turret. I have used them on several scopes in the scenario you describe and they have solved the problem every time - you don't even notice the shims are fitted.

 

[Loki]

Hi

Can only reiterate the Burris Sig-Zee rings too - you can also get a shims set giving varying off-sets if your need requires - and less likely to crimp the scope tube.
I have them on several of my scopes.

L

 

[bryn]

Burris Signature Zee rings - they include dedicated +/- protective shim inserts for front and back rings. Once the scope reticle is optically centred you fit shims as an opposing pair within both sets of rings to save having to make gross elevation adjustments using the turret. I have used them on several scopes in the scenario you describe and they have solved the problem every time - you don't even notice the shims are fitted.

Unfortunately they only do 1 inch tube mounts (I need 30mm) for a dovetail 11mm action unless I fit a picatinny rail and fit weaver mounts to the rail which I may end up doing.

Thanks
bryn

 

[pinkfoot1]

Not wishing to teach granny to suck eggs.....but......
I assume this is new acquisition otherwise you would have posted years ago. The Finnfire is an extremely well engineered rifle and unlikely to be at fault. Your scope may be a different matter.

There are two points where line-of-sight coincides with bullet trajectory - 1. At point of aim and 2. where flight of bullet on rising trajectory passes upward through your line of sight closest to you. Make sure this isn't your error. Find out how many elevation clicks you have on the scope and set it half way. Try sighting in again, boresighting at initially 25yds and winding elevation onto target.

If this doesnt sort it check the security of your barrel. Remove the barrelled action from the stock, undo the two barrel clamp bolts and withdraw the barrel. Check both barrel and action for absolute cleanliness. Put a fired case in the barrel chamber, insert bolt, locked and cocked, insert barrel ensuring location of alignment keyway and retighten barrel locking bolts. (The point of inserting the fired case is to ensure correct headspace when barrel is inserted and held tightly against bolt face)

Hope this helps!

 

[Oracle]

Unfortunately they only do 1 inch tube mounts (I need 30mm) for a dovetail 11mm action unless I fit a picatinny rail and fit weaver mounts to the rail which I may end up doing.

Thanks
bryn

Bryn

They do 30mm Weaver mounts in medium or high. If you cannot find or fit a Weaver rail to your Finnfire then an option may be to use a set of BKL Technologies Weaver to 11mm dovetail riser mounts. Using these, the base of your ring mounts will be about .5 inch higher, but that may be an advantage depending on size of your scope objective lens.

 

[fizzbangwhallop]

I had exactly the same problem mounting a 1" tubed Swarovski AV 6-18 x 50 with the BR reticle to my Mk1 Finnfire and got round it by using a Sportsmatch OP15C 20moa inclined 1 piece mount.
Sportsmatch | Air Rifle - Rimfire Rifle Scope Mounts Rings

I'm not too far from the factory and they kindly milled out an ejection port for me although that's not actually needed..... gives a gnats dick of clearance to the barrel and works perfectly.

About a year later I bought a CZ American in 17HMR and got another AV Swaro from Gregor at Macleods of Tain which was just a few numbers different on the Serial Number, so out of the same batch as the original.
This also ran out of elevation in normal mounts so I bought another OP15C.

However, despite everything being the "same" I couldn't get this combo to zero at all so I switched the 'scope and mount from the Finnfire to the .17HMR...... Result, no problems zeroing and again the gnats dick of clearance to the barrel. Perfect.

Fitted the newer 'scope/mount to the Finnfire and zeroed that too without a problem.

To this day I've never got my head around it and have given up trying... (not that it worries me now as the .17HMR is long gone and I've a spare barrel for the Finnfire in .17MachII).

What I'm really saying is that just be aware that not everything is made equal.

Cheers

Fizz

 

[B&W FOX]

ATP66
http://www.tawnadoairguns.com/sportsmatch_scope_mounts_30mm.php

 

[bryn]

Thanks to all in particular pink foot for talking through the barrel removal. I have temporarily shimmed my optilock mounts by putting sliver of coke can between the rear ring and base and I must say it feels very secure. In the long term I will go with one of the above once I have done a little research. It needs to be really secure as a Ward 800 and IR torch will be attached.

Thanks
bryn

 

[fizzbangwhallop]

Thanks to all in particular pink foot for talking through the barrel removal. I have temporarily shimmed my optilock mounts by putting sliver of coke can between the rear ring and base and I must say it feels very secure. In the long term I will go with one of the above once I have done a little research. It needs to be really secure as a Ward 800 and IR torch will be attached.

Thanks
bryn

Your thanks to pinkfoot about removing the barrel just reminded me of something to be aware of when fitting scope mounts to a Finnfire action... especially the one piece Sportsmatch!

When I was first tightening up the side clamp bolts of the inclined one-piece mount, I just gave them a little extra 'tweek' and heard a crack! The force exerted by the clamp along the line of the dovetail groove had cracked the action through into the hole the barrel slides into, scrapping it in the process! I would post a photo 'cept photobucket now want money to host 3rd party images! (How very dare they)

I managed to get another Finnfire at a decent price and ended up with a complete set of spares...apart from the action.

I now use a proper torque screwdriver on any screws on a gun.

Cheers

Fizz

 

[bryn]

Cheers Fizz. Good to know
bryn

 

[Dovebob]

Fizz,

I recently got a .17 Mach II barrel for my Finfire. The bloke who I bought it from (an RFD) showed me how to fit the barrel into the action. The action he used to show me had been cracked in the same way as you describe. He'd had it welded by a specialist and had then milled the inside and the outside of the action to make it good.

I'm not sure if you still have your broken action but if you do it seems that it could be repaired. I'll send you the details in a pm if you're interested.

Cheers,

Bob