Which scopemount for Picatinny-Rail?

[Para Bellum]

Hi there,

how should I best mount a 30mm Swarovski Z6i 2,5-15x56 onto a Steyr Elite .308?

Here is the rife, it has an extra long picatinny-rail, but should I use two rings or an integral mount?

like this:

or like this:

Thank you for your time and thought!
Stay safe,
PB

 

[Skyyr]

Go with the integral mount. Even on a perfectly in-spec picatinny rail, there is an allowance for a margin of error. The integral mount has the rings attached to its base, so their alignment isn't affected by the rail.

The separate split rings attach to the rails in two separate areas (compared to the integral attaching at one point). This means that if your rail isn't perfectly in spec (and virtually none ever are), the rings will stress your scope, leaving ring marks and potentially damaging your tube. The fix is to have the rings lapped, but if you get the integral mount, you won't have to worry about it at all.

Separate ring pairs are only needed when the mounting rail isn't continuous, such as with traditional bolt-action rifles where the scope rings straddle the action.

I'd suggest looking at either the Nightforce Unimount or Near Manufacturing Mounts.

 

[Para Bellum]

thank you!

 

[mapsjanhere]

Not a true comparison, you're having quick-detach rings vs. permanent mount. I personally would go with the QD rings to be able to take the scope off during transport, cleaning etc.

 

[Skyyr]

Why would you want quick-detach on a bolt gun? They serve no purpose.

The only advantage quick-detach offers is just that, a "quick" detach. Since there are no backup iron sights, or a need to remove an optic quickly, the stability of a bolt-torqued mount is a significant advantage. On AR's, it's a different matter. For bolt guns, however, the integral torqued mounts are preferred.

Even if QD is "required," integral QD mounts still trump separate QD rings, all other things being equal.

 

[Art Eatman]

Lower is generally better for a good cheek weld.

 

[Palmetto-Pride]

This means that if your rail isn't perfectly in spec (and virtually none ever are),

So what makes you think the integral mount will be perfectly in spec? I mean a rail machined into the receiver IMO would be more in spec than some after market integral mount. I have used two piece rings on my AR and never had a problem returning to zero when I remount my scope and I have taken it on and off many times to go between my red dot sight and scope.

 

[Skyyr]

So what makes you think the integral mount will be perfectly in spec?

You're missing the point. If the rail is out of spec and the rings attach directly to the rail, then the scope will be stressed. An integral mount already has the rings trued to the base, so while the main picatinny rail might be out of spec, no stress is transferred to the scope tube because the rings that hold the scope are not mounted to it. Any stress will be between the main rail and the mount base, not between the rings and the scope.

It's not an issue of returning to zero - it's about avoiding stress on the scope tube (and therefore ring marks and/or a damaged tube). I have no doubt that a good set of QD rings will return to zero, but, unless you've lapped the rings, I guarantee you that they will not be trued to the scope and you will have points of stress and you will develop ring impressions on your scope. Lapping the rings will fix this situation, but why bother when you can avoid it altogether by getting an integral scope mount?

With this in mind, the answer is simple: get an integral base whenever possible. In fact, the only reason not to get one is if you have a traditional bolt-action rifle, or you have an extremely long scope tube that requires rings at odd points to support the scope's weight. If you can't get or just don't want to get an integral mount, get a set of rings, but make sure to lap them.

 

[mapsjanhere]

Skyyr, so for some reason you assume that the rail will be automatically defective while the integral mount for some reason is automatically perfect? Each their own I guess.

 

[Skyyr]

Skyyr, so for some reason you assume that the rail will be automatically defective while the integral mount for some reason is automatically perfect? Each their own I guess.

No, I'm not assuming anything. When an integral mount (read: true one-piece mount milled from a solid aluminum block) is manufactured, the rings are cut as part of the mount. Provided that we are talking about a quality mount, the rings themsevles are cut using a ISO-certified 30mm (or whatever size tube the rings are cut for) cutting rod that surpasses tolerances on most scopes. Therefore, the rings are virtually never the loosest tolerance. In addition, since they are milled as one piece, they CANNOT come out of true / alignment. It is physically impossible. It doesn't matter if the rail it attaches to is in spec or not - the rings themselves are aligned with the scope mount. Even if the entire mount was canted 90* perpendicular to the rail, the rings themselves would remain perfectly aligned. This is why the integral mount imposes no stress on the scope.

Keep in mind, I'm not talking about mounts like Larues, where the rings bolt onto the base - the rings are not integral to the mount and therefore can be out of alignment. I'm talking about TRUE one-piece mounts like Nightforce Unimounts.

On individual split rings, the rings alignment or lack thereof is directly proportionate to the rail it's attached to. If the rail is perfect (which they never are), then the rings will be aligned perfectly. If it's out of spec, then one or both of the rings will cant, resulting in misalignment of the scope. A lapping kit will show exactly what I'm saying here. Using a lapping bar will remove the cant/misalignment of the rings by re-boring the alignment. This is the entire reason why lapping was invented - to correct the alignment issues individual rings cause.

If given the option, an integral mount is ALWAYS preferred for the above reasons and should be used, unless some other factor (such as height over bore or ring-spacing issues) takes precedence and requires individual rings.

 

[Para Bellum]

Since there are no backup iron sights...

I intend to put backup ironsights on the rail (flip-ups), just in case...

Thanks, by the way, there was a lot of helpful information in that thread already!!!