Sako Optilock bases: different types?

[Sako75Hunter]

Just trying to get my head around something here, hopefully someone familiar with Sako will be able to explain this to me.

Looking at online images of Sako Optilock set-ups, and with regard to the forward base + ring, I've noticed the following. In some cases the ring is positioned at the forward end of the base, while in others it's to the rear, as in these 2 images:

I presume Optilock bases come in different types, with a drilling for the ring either to the front or to the rear, and the appropriate one is chosen according on the action length, the length of the mounting area on the scope, and maybe other factors I'm not aware of. I know there are other Optilock bases that cantilever out over the bolt opening, but this question doesn't concern these.

I can't find any reference to, or mention of, the availability of 2 different Optilock base types, as in the images above, anywhere. Can anyone enlighten me on this? (I've probably overlooked some very simple and obvious explanation!)

 

[Wsm]

Optilock bases do indeed come in either Short or Long to cater for the differing action lengths /scope tube dimensions etc

 

[paul o']

Yup some are for short action ,long actions, tikka m558 -TRG forward ring mount, extended that come over the ejection port ,Sako QM ,oh and weaver mount just to add that in the mix ?
Then the one's that are not Sako but will fit NOW the list is growing lol

 

[Sako75Hunter]

(I've probably overlooked some very simple and obvious explanation!)

Optilock bases do indeed come in either Short or Long to cater for the differing action lengths /scope tube dimensions etc

Many thanks Wsm!

 

[Dalua]

Interestingly, your top pic seems to show the 'short' bases on a long action, and the lower pic has the 'long' bases on a short action - which just goes to show that, as long at it works with your 'scope set-up, it doesn't matter a great deal.

The main thing to note is that when using the bases/rings, the rear edge of the forward base should be level with the front of the receiver opening, as in the second pic.

 

[long_range_rob]

You can also get the ring mounts which are one piece rather than bases and rings, and don't forget the reach back mounts for the magnum actions which put the front ring over the loading port.

 

[long_range_rob]

http://cdn1.sako.fi/sites/default/files/Optilockbase.pdf

 

[Sako75Hunter]

Interestingly, your top pic seems to show the 'short' bases on a long action, and the lower pic has the 'long' bases on a short action - which just goes to show that, as long at it works with your 'scope set-up, it doesn't matter a great deal.

The main thing to note is that when using the bases/rings, the rear edge of the forward base should be level with the front of the receiver opening, as in the second pic.

After Msm's clarification I realised that my (very short action) Sako 75 in .223 is fitted with long action bases. The bases came with the (second-hand) rifle, so I would have used them anyway, even had I known they were the worng ones, given the exorbitant price of new ones. However, to get the proper eye relief on the scope I had to set the forward base about 3/8" forward of the receiver opening.

As far as I'm aware this has never caused any problems in any way, so I'm curious as to why you say the rear of the front base should be level with the opening? I thought the whole idea of the Sako tapered dove-tail was that by moving the front base forwards or backwards when zeroing, you could very roughly adjust the windage and get it in the ballpark area before making finer adjustments by moving the scope reticle?

 

[2130martin]

Never heard of that before,have always fixed mounts and scope rigid before zeroing.

 

[Sako75Hunter]

Never heard of that before,have always fixed mounts and scope rigid before zeroing.

I did the same as you when I was zeroing the above rifle/scope. I'm just saying this because, if true, there isn't really any 'correct' position for the front base along the receiver rail in relation to the ejection port, although theoretically somewhere in the middle would be best.

Optilock bases and rings are machined from a solid block of steel, Cr-Mo alloy or stainless, just like our rifles. The front bases have a solid angled left side and a similarly angled right side with a clamping device. This base design connected to Sako rifle´s integral dovetail rail allows you to adjust the horizontal position of the scope objective end without touching the scope adjustment.

http://www.sako.fi/scope-mounts

 

[Sako75Hunter]

After Msm's clarification I realised that my (very short action) Sako 75 in .223 is fitted with long action bases. The bases came with the (second-hand) rifle, so I would have used them anyway, even had I known they were the worng ones, given the exorbitant price of new ones.

In addition to the wrong bases, this rifle also came with rings that were either 'medium' or 'high', which I replaced with a new set of 'extra-low' rings, as I was mounting a scope with a 42mm objective. These rings are pretty much unusable with any normal scope, even the 56mm I recently bought, as they would place the scope way too high. As far as I'm aware, the new scope will require the 'low' Optilock rings.

Aside from the issue of why the previous owner had rings on the rifle that were nigh on useless, it's beyond me why Sako market rings that are too high for a big objective like 56mm as 'medium', or even why they sell them at all, really.

Has anyone else ever managed to understand this?

 

[2130martin]

There are a number of reasons the previous owner may have wanted the scope mounted higher.......for Fitment when shooting,for mounting ad on NV etc,for longer range shooting if scope had limited elevation adjustment.

 

[Sako75Hunter]

There are a number of reasons the previous owner may have wanted the scope mounted higher.......for Fitment when shooting,for mounting ad on NV etc,for longer range shooting if scope had limited elevation adjustment.

Thanks for that Martin. Surely as regards fitment when shooting a good cheek weld needs the scope down as close as possible to the barrel?

 

[2130martin]

Thanks for that Martin. Surely as regards fitment when shooting a good cheek weld needs the scope down as close as possible to the barrel?

Or a cheek riser if more comfortable.......

 

[8x57]

Thanks for that Martin. Surely as regards fitment when shooting a good cheek weld needs the scope down as close as possible to the barrel?

Not always so, it will depend on the build of the shooter too. Some shooters may be rat faced (skinny faced) while some of us may be cuddly (just a little bit more padding).
Myself I always like to get the scope down as low as possible to the barrel, obviously.

 

[Dalua]

I did the same as you when I was zeroing the above rifle/scope. I'm just saying this because, if true, there isn't really any 'correct' position for the front base along the receiver rail in relation to the ejection port, although theoretically somewhere in the middle would be best.

Optilock bases and rings are machined from a solid block of steel, Cr-Mo alloy or stainless, just like our rifles. The front bases have a solid angled left side and a similarly angled right side with a clamping device. This base design connected to Sako rifle´s integral dovetail rail allows you to adjust the horizontal position of the scope objective end without touching the scope adjustment.

http://www.sako.fi/scope-mounts

The quotation in bold from SAKO's website is interesting, and is at odds with the actual instructions which come with the bases - which, as I said, direct that 'the rear of the front base should be level with the front of the ejection opening'.
I have always imagined that this was because in this position, the front and rear bases would be pretty much in a straight line pointing down the line of the bore - a good starting-point for fitting a 'scope.


The instructions for fitting the one-piece ringmounts suggest that the front ring should be fitted to start with half-way along the front dovetail. I imagined that this also gave an approximate lining-up of front and rear mounts. Fair enough. However, the instructions for these go on to say that having started in that position, one can move the front mount forwards and backwards as may be expedient to make, as has been suggested here, coarse windage adjustments: 1mm forwards shifts the POI about 1" right at 100yds.

So, with the one-piece ringmounts, you start with the front ring in the middle and can change POI for wind by moving the front mount backward and forwards.
With the bases/rings, you start with the front mount at the back of the front dovetail (where presumably it is approx. lined up with the rear one) and as far as I can tell from the instructions, you leave it there. To my eye, it looks better in that position, but that's assuming your 'scope fits with it there, of course!

The instructions (at least, the ones I've got) don't give the option to shift the POI right by moving the front base forwards from the initial position. I'm sure you could do that if you wanted to, though.

 

[2130martin]

The quotation in bold from SAKO's website is interesting, and is at odds with the actual instructions which come with the bases - which, as I said, direct that 'the rear of the front base should be level with the front of the ejection opening'.
I have always imagined that this was because in this position, the front and rear bases would be pretty much in a straight line pointing down the line of the bore - a good starting-point for fitting a 'scope.


The instructions for fitting the one-piece ringmounts suggest that the front ring should be fitted to start with half-way along the front dovetail. I imagined that this also gave an approximate lining-up of front and rear mounts. Fair enough. However, the instructions for these go on to say that having started in that position, one can move the front mount forwards and backwards as may be expedient to make, as has been suggested here, coarse windage adjustments: 1mm forwards shifts the POI about 1" right at 100yds.

So, with the one-piece ringmounts, you start with the front ring in the middle and can change POI for wind by moving the front mount backward and forwards.
With the bases/rings, you start with the front mount at the back of the front dovetail (where presumably it is approx. lined up with the rear one) and as far as I can tell from the instructions, you leave it there. To my eye, it looks better in that position, but that's assuming your 'scope fits with it there, of course!

The instructions (at least, the ones I've got) don't give the option to shift the POI right by moving the front base forwards from the initial position. I'm sure you could do that if you wanted to, though.

Thank god I never read the instructions or I would still be sat scratching my head over that job!!!

 

[Dalua]

it's beyond me why Sako market rings that are too high for a big objective like 56mm as 'medium', or even why they sell them at all, really.

Has anyone else ever managed to understand this?

The medium rings do seem pretty high. I had to use them for a x56 'scope on a heavy-barrelled rifle.
x42s on sporter rifles seem happy in extra-low, or the elegant one-piece ringmounts. I've also got a x50 on a sporter with the one-piece mounts - but it depends on where your set-up puts the objective relative to the barrel-profile, as well as objective diameter (and whether you like Butler Creeks, of course).

 

[Sako75Hunter]

And I suppose the odd pair of 'high' Optilocks could actually be required for those 72mm objective lens Zeiss scopes you sometimes hear about.

Now I know what to do with that set I have left-over!

 

[KentCountryGent]

This is an old thread I know, but does anyone know if you can fit long action based to a short action without any problems? I've got a Sako 85 and have just bought some off a chap without realising I should have asked first! Any wisdom would be appreciated.
Initial fitting shows the side clamps are not quite straight when tightened up...