Optilock advice please

liongeorge

Well-Known Member
I have a Docter unipoint fitted to my Sako 75 .243 with optilock mounts (admittedly both scope and mounts are second hand) After initial zeroing have shot 9 deer all at fairly close range 50 - 120yds. The last one bullet hit much higher than expected and clipped the spine, deer went down but I was concerned. So at the weekend went to check the zero and it was shooting all over the place, very inconsistant in a 6" area.
I think the scope is good and the only thing I'm not happy about is the optilock bases.
The front base I can push right up tight on the taper but the rear base has a peg that lockates on the action but does not alow the taper do anything at all and therefore it relies on the small clamp to hold it on the right hand side and the base itself is not in contact with the dovetail at all on this righthand side. Can this be right or is this a rear base for a different action? Do they differ?
Any advice much appreciated.

George
 
My experience with Optilocks would suggest the following:

1. Yours sound like the correct bases, as AFAIK Tikka ones would not tighten on the rear dovetail.
2. The front base is I think meant to be flush with the rear end of the dovetail and fixed in that position by tightening the screw, rather than wedged onto the dovetail and then tightened as you describe. Unless you have the 'one piece' mounts (rather than rings and bases), in which case the front mount can be moved fore and aft to adjust for L/R point of impact to some extent.

Please forgive me if I'm enquiring after the obvious, but you presumably have the plastic inserts in the rings?

My not-terribly-extensive experience would suggest that correctly fitted and tightened Optilocks are unlikely to be a source of inaccuracy. I have currently three c/f rifles with them fitted, and have used these over 6 years without difficulty.

I'm sure other more competent commentators will attend soon!
 
There are Optilocks for short action and long action, yours is probably short action.
Check on the sako web site for info.
The length of the rear short base is:29.87mm
narrow end of taper 10.5mm
wide end of taper: 12mm
When you mount the rear mount, you should position it so the peg is just off seating in the hole, so recoil will push the mount down the taper slightly firming it up.

I have gone onto the Redfield base system as it is cheaper than optilocks and you have a range of rings to use.

http://www.jjkshootingsupplies.co.u...-base-sako-with-dovetail-receiver-gloss/1182/

He is selling the weaver equivalent bases on the bay for £20

with these rings
http://www.jjkshootingsupplies.co.uk/products/leupold-standard-rings-1-quot-low-matte-49898/736/
 
jack said:
There are Optilocks for short action and long action
This is true, but I think the only difference is that the front base has the ring mounted at its front edge for the short action and its rear edge for the long action. As far as I'm aware, depending on the dimensions of the scope (i.e. if it fits between the rings reasonably) you can use either kind on either length of action.

jack said:
When you mount the rear mount, you should position it so the peg is just off seating in the hole, so recoil will push the mount down the taper slightly firming it up.
I'm not sure this is correct. My view is that the rear base should be positioned with the pin against the front edge of the u-shaped cutout in the top of the receiever before the mounting screw is tightened. The idea is that it moves nowhere!

My father has the Redfield system on his Tikka, but I favour the Optilocks for elegance and finish.

I'd suggest that if one actually has Optilocks, it's worth trying to make them work before swapping to something else!
 
Dalua said:
jack said:
When you mount the rear mount, you should position it so the peg is just off seating in the hole, so recoil will push the mount down the taper slightly firming it up.
I'm not sure this is correct. My view is that the rear base should be positioned with the pin against the front edge of the u-shaped cutout in the top of the receiever before the mounting screw is tightened. The idea is that it moves nowhere!

This was the advice from an experienced gunsmith.
 
Thanks guys,
Jack I've measured my rear base and it is exactly to your dimensions and I apreciate what your saying about pin location.
Dalua I think your right in that the only difference between the short and long is to do with the possition of the ring on the front base.
My previous point has not been answered though and I have done a little more experimentation. I removed the pin on the rear base and slid it up on the rifle to see how far it will go up the taper . It went miles up the taper and overhung the action. I'm stil not satisfied in my own mind that it is a good idea that the base is only in full contact on the left hand side and is only held on the right with the small clamp. This will also mean that the base is not central but slightly pushed to the right.
I've ordered a new set of bases anyway as I found I could rock the pin in its hole and I wanted some extended bases to get the eye relief correct.
I'll let you know how I get on.

George
 
George, this is the problem i had with my 85 and optilocks.
Fine for a while but kept working loose. Worst case of this was going to shoot a large medal Fallow in the New Forset and squeezing a shot off high in the shoulder to try and drop it instantly, which the buck did but about 2ft towards its rump! Poor beast , the bullet had gone through the spine and dropped it into a deep ditch. Sadly died an ungracefull death with another shot at point blank.

Very embarassing for me as the guide must of thought I was a right tw*t who couldnt shoot. The next day I shot the gun the mounts were loose so that was it, decided to get rid of it and bought a R93.

Now have a Schultz and Larsen with apel quick release mounts.

2 good friends of mine who cull a lot of Deer both have Sako's, one a 85 like mine and the other a custom 75. To my knowledge neither have had any problems like mine.
 
Also to add that I have recently seen a fair amount of local Sako users having fitted their guns with warne type rings. According to one local RFD this is because GMK have run out of optilock bases and warne do the job better and at halk the price.
 
Never had any problems with optilocks coming loose. One needs to watch out that the center screw that holds the base and top bit together is tight.
I used green locktite when putting tops and bottoms together.
Generally optilocks must be crammed down well with a good fresh allen key. I tightened the fronts and back mounts on the dovetail lightly, gave them a light wack forwards then crammed em down.
Took some tumbles with the rifle in the hills but scope never went out.

In the meantime i sold the optilocks and went for recknagel mounts and a picatinny rail from roedale. All aluminium and lighter.

sakorail.jpg


edi
 
Another vote of confidence for the optilocks. I have had optilock mounts on my 595 for six years now with not the slightest problem. If I were to ever buy another Tikka or Sako I would certainly go for Optilocks again.
 
cheers sam,

The warne ones look good , optics warehouse have them not sure if I need the medium or high ones though.
I do fancy a picatinny rail ejg so in future a might bight the bullet and speak to nears or roedale.
Found a post on another site describing exactly what I have found with the rear base arangement, he concluded I believe correctly that all scopes on optilocks are pushed off the centre line (it also slightly tips the rear base). This may not be a problem if you have enough adjustment on your scope but isn't ideal. he got over it by removing the peg and shimming the base tight onto the taper by cutting strips of feeler gauge and then clamping it. What a wind up and could you trust it. I would have expected better from sako.
I know there must be hundreds of satisfied optilock owners out there but its knocked my confidence and when you actually look how the system works it seems crap. Anyway new bases turning up tomorow, wish I'd gone for warnes now but I'll give them a go, I'm a bit of an engineer so will work out a way of fixing it.
 
Where ignorance is bliss, 'twere folly to be wise.

I'm glad they've worked so far for my purposes. Perhaps I should see this as a trumpet-blast calling me to better things, but in fact
I just hope they continue to work, despite the fact that the scope is off-centre, tilted and only just hanging on by the skin of its teeth.

I live, but don't learn ;)
 
Thanks for your help guys, in the end I removed the (in my mind useless) peg in the rear base, cleaned everything off with solvent, aplied loctite to everything and tapped the base up onto the rear taper (after fitting ring base of course). It slightly overhangs the action but is absolutely rock solid.
Took it out , bore sited it ,3 shots to get to zero 1" high at 100yds. Next two shots keyholed spot on zero.Good enough for me. Very relieved and pleased.
Took the oportunity to change to Norma 100gr SP as I was running low on Lapua which I wouldn't be able to get hold of any more. I think my gun must like them.
I think a picatinny rail might be on the list for xmas though.

All the best George
 
I suppose one good thing about the peg (apart from the fact that it really does stop the mount moving, if fitted correctly) is the ability to relocate fairly exactly a scope on to a rifle on which it's been previously mounted and zeroed.

I did this on Saturday, replacing a 6x42 4A with a 3-12x50 TDS-Plex with a view to assisting holdover for hill-stalking. It returned to within 10mm of the zero it had when I removed it from the rifle two years ago.

The main thing apart from one's kit working properly is, I think, to have confidence in it. If that takes a bit of Loctite and light engineering, so be it; happy shooting! :)
 
Apparently the optilocks can be centred in the following way:
http://www.24hourcampfire.com/ubbth...topics/3514944/Re_Sako_Optilock_s_vs_Talley_Q
"....start with an Optically centered scope. (Hold the scope objective flat against a mirror and adjust the crosshairs until they match the shadow reticle). Install the scope in the rings but leave the front screws loose. While boresighting slide the front ring back and forth until you get the reticle centered boresighted, then tighten up the screws. Usually it will be somewhere around the middle of the front dovetail."

I've tried this method and it works for me. No more shimming rear bases. Also I have no issues with the rigidity of the bases and how they clamp to the dovetails. It is important to loctite the screw joining the bases and rings otherwise it can eventually come loose and cause erratic grouping. Otherwise absolutely fine.
 
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