Scope ring height - moderator need advice.

Or use a brake if you're at a range... The difference between a mod and a brake is night and day in terms of mirage!

It's one of the main reasons I run brakes for PRS as a pose to mods!

Ben

Thankfully we have banned muzzle brakes to their own evening at the tunnel range...with COVID we are down to two lanes at a time, but when we were at four lanes and somebody used a muzzle brake it was horrible for anyone either side...you get the full blast and useless to try for accuracy getting buffeted. :(

Though talking of heat shimmer....in certain weather conditions the whole tunnel gets steamed if someone forgets to put the extractors on...like here...



IMG_4145.jpeg
 
Heat shimmer goes upwards generally....another few millimetres of line of sight height above the bore is not really worth factoring is it? More important to reduce parallax issues with the trajectory?

If you are shooting lots of strings at a range then you can use a little fan to blow the heat haze away...I do now...but I developed the technique of blowing along the barrel just prior to pulling the trigger before I bought the fan....

Alan

If mirage was of no concern, then thermally insulated moderator covers and (at the extreme end) mirage bands wouldn't exist.

A *reasonable* height above bore is a good thing, and you generally come to this realisation after owning dial optics with considerable elevation travel. Even more so when a moderator is fitted.

I too own a fudd gun (Sako L461) and their optics mounting system was state of the art in the late 40's but they resisted change until the abomination which is the S20 (how about an integrated picatinny rail? But we will cut it with a needless gap in the middle to stop use of proper one piece Sphur mounts 😜).

Hope the OP finds a workable solution. Most of the picatinny options for Sako 75/85's are after-thoughts which create worries about tolerance stack (dovetail-rail-mount). Have seen some mill off the Sako dovetails :eek: or just do a 'glue and screw' job over the top of them.

NEAR rails are worth a look, but worth the money? The name on the side of the action leads people astray sometimes.

I'd start again with a Howa or even better Rem 700 build as Sphur make a nice picatinny rail and slimline hunting rings to fit.

@ejg has pics of a nice Remmy build.
 
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Solve your range heat haze by rolling a loose paper tube round the moderator (use a little tape to hold it in a tube shape) this gets rid of any heat haze. Simply slip it off between strings to maximise the cooling of the moderator. Problem solved - cost 1 sheet of A4 and 2” of sellotape.
N
 
If mirage was of no concern, then thermally insulated moderator covers and (at the extreme end) mirage bands wouldn't exist.

I did not say it was of no concern...but that the line of sight a few more millimetres above the moderator would make little difference....an entirely different point. I wouldn't have waffled on about fans if I thought it wasn't an issue.

A *reasonable* height above bore is a good thing, and you generally come to this realisation after owning dial optics with considerable elevation travel. Even more so when a moderator is fitted.

I don't know how critical it would be for long range adjustments...but I would still try for the minimum mounting height which would allow the full amount of dialling. Is there any advantage to mounting higher than that?

I asked earlier why NV units like the Pard 008 were always mounted so high...that can't be for long range adjustments....is there any other advantage to mounting that high above the bore from an alignment with the trajectory point of view? It is plainly crap from the cheek weld side of things.

Alan
 
I don't know how critical it would be for long range adjustments...but I would still try for the minimum mounting height which would allow the full amount of dialling. Is there any advantage to mounting higher than that?

20 MOA inclined bases would not be a thing if dial scopes with large elevation ranges did not cause issues. Often, a level base with low height over bore will mean that you can't use the entire elevation range of the scope.



Examples of ELR (Extreme Long Range) shooting on the channel below. Look at their rigs, especially the optics.

 
Often, a level base with low height over bore will mean that you can't use the entire elevation range of the scope.
I am sure that is the case....

But my query was, is there any advantage to mounting it higher than the point at which you can use the entire elevation range of the scope?

Alan
 
Thankfully we have banned muzzle brakes to their own evening at the tunnel range...with COVID we are down to two lanes at a time, but when we were at four lanes and somebody used a muzzle brake it was horrible for anyone either side...you get the full blast and useless to try for accuracy getting buffeted. :(
Yep agreed, I tried to zero one of my rifles for a competition next to a 375 CT with a brake once, physically rocked me and the rifle onto one bipod leg when it fired!
That said where only one person is shooting on a range or there is good spacing they are hard to beat!

Ben
 
Or maybe I don't need to worry about height??
I have two Sauer 404‘s both with Sauer’s own scope mounts which are very low, I have a Stalon 145 (Biggest one they did) and a Sauer/F&D on the other even on low mag there is no issues scopes are Z8’s
 
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To achieve maximum point blank range. If the scope was level with the muzzle, the bullet would be dropping out of the line of sight from the outset. With the scope mounted just above the muzzle, the bullet rises to the line of sight then falls back below it.
Raise the scope a little more and the bullet crosses the line of sight then falls back through it some distance further away. The higher the scope, the greater the distance between en the two intersection points.
Now for a given target size, say 4”, you don’t want the bullet to rise more than 2” above the line of sight - this is the optimum height for your scope.
This works better on a flat shooting centrefire than it does on a 22 LR. Air rifle shooters use an app called Chairgun to give them the best zero distance for their setup of which scope height is a significant variable. Deciding/calculating scope height first is just solving the same problem backwards.
N
 
I am sure that is the case....

But my query was, is there any advantage to mounting it higher than the point at which you can use the entire elevation range of the scope?

Alan

Depending on the turret configuration, you are looking at around 65 MOA worth of downwards elevation travel on a PMII. Add to that a reticle designed for hold-overs and you still have some room to play with.

If you read Cpl. Craig Harrison's account of the *at the time* world's longest kill shot (2,475m) he had run out of elevation and was holding off on the reticle. I think L115A3 was issued with the same scope that the OP has, except the rifle is a .338 Lapua Magnum.

L115A3_sniper_rifle.webp

As said before, look at 'Mark and Sam Afterwork' for examples of a generous height over bore, on one video you will even see the use of what I believe is a reflector sighting system (aiming below the barrel, much like volley sights of old SMLE's).

I think I've put a decent amount of effort into explaining this, to the point I feel like a parent who is being subject to continuous 'but WHY?' questions from a 5 year old.
 
I have two Saue 404 both with Sauer’s own scope mounts which are very low, I have a Stalon 145 (Biggest one they did) and a Sauer/F&D on the other even on low mag there is no issues scopes are Z8’s

OK, but do you dial elevation?
 
OK, but do you dial elevation?
I have a ballistic turret on one of the Sauer’s a 300wm and it’s set for 100-200-300-400 yards I have dialled it to 400 yards still no issue at that range I would also be winding the mag right up
 
I think I've put a decent amount of effort into explaining this, to the point I feel like a parent who is being subject to continuous 'but WHY?' questions from a 5 year old.
You do seem to have taken a lot of trouble to explain the requirements of mounting a long range scope...thank you.

But it may have been less frustrating for you if you had actually answered my questions...which were simply posed to query why "mounting as low as possible" which you said you were puzzled by, conflicted with any requirements of mounting a longe range scope.

But my query was, is there any advantage to mounting it higher than the point at which you can use the entire elevation range of the scope?

You appear to have interpreted "mounting as low as possible" as "mounting below the level at which you can achieve maximum elevation adjustment with a long range scope".

Looking at the comments on here, I am puzzled by all the 'mount as low as possible' answers.

Clearly not factoring heat haze from the moderator and the fact that a dial scope actually needs more height over bore (or even better, an inclined/20MOA base).

"Mounting as low as possible" includes for any height above the bore necessary to achieve the correct functioning of the scope, otherwise it would not be "possible"

It includes for the entire elevation range of a long range scope....why would you assume anyone meant you mount it so that a scope was not fully usable?

Alan
 
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Sorry to butt in, but is "dial scope" an established term now? If so, is it shorthand for "a scope with target/tactical turrets designed to allow users quickly to dial-in trajectory corrections", or does it mean something else? Can a scope that also has holdover points in its reticle qualify, or should we call that a "hybrid scope"? Is there such a thing as a "hold-off scope". I've nothing against handy terms for useful things, but sometimes I need a little help keeping up!
As for the OP, I suspect you have "too much scope", i.e. your PMII is has much more adjustment than you need for the kind of shooting you will probably be doing with a Sporting rifle (and more weight and less length). If so, maybe change the scope instead of the rifle. This would solve your eye-relief issue and give you a handier rifle into the bargain. Trade-in the S&B police/military sniper's scope for a scope by a company that specialises in hunting optics (e.g. Swarovski).
And once you have such a scope, set it up so that it comes naturally, comfortably and consistently to your eye when properly mounted in your shoulder. Don't worry about the moderator or trying to dial up so far the barrel gets in the way. That's a different game. No worse. No better. Just different.
 
Hi, I’m not sure if this helps but I have three rifles with 34mm tube scopes. They are sat in Warne medium mounts. On picatinny rails. The scopes just clear the barrels.
 
Guys thanks for all the replies there's alot to digest here. And yes as a few have pointed out about the scope yes it is way to much scope for a 22 250. I know i will never get to use its to its full potential on a 22 250. I got a really good deal on it while abroad and looking back I should have went for a smaller mag. I don't think I'll ever sell it now though so will just put up with extra size and weight. From all the answers it seems I was thinking about the Moderator but it will be fine just mount it to what makes me comfortable. I'll more than likely never take a shot at a fox past 250-300 yards at light and 150-200 dark at most I'd say anyway.
 
I used to be a fan of mounting my scopes as low as possible over the bore, but Mark and Sam have converted me to mounting them higher, so that my eyes are level when sighting the rifle. I shoot with both eyes open and find this higher position more comfortable than squinting through the scope with my head cocked over to one side, as I used to do with my low mounted scopes.
 
I have a ballistic turret on one of the Sauer’s a 300wm and it’s set for 100-200-300-400 yards I have dialled it to 400 yards still no issue at that range I would also be winding the mag right up

OK, but you are not looking at a huge amount of dial for 400 yards/meters from a 300WM, especially if you zero at 200 yards/meters.
 
OK, but you are not looking at a huge amount of dial for 400 yards/meters from a 300WM, especially if you zero at 200 yards/meters.
The rifle is zeroed at 100 yards and I use the turret settings to shoot out to 400+ in hunting terms that’s a very long shot in my book. It can only be range work if anyone is shooting past that
 
Yep agreed, I tried to zero one of my rifles for a competition next to a 375 CT with a brake once, physically rocked me and the rifle onto one bipod leg when it fired!
Ben
Experienced this twice at the BSRC range:

1. Group testing a 22 hornet from a front and rear bag. Just about to let the trigger down and “boooom” goes the MB equipped rifle on the adjacent bench. My crosshairs moved some 4”!

2. Lining up my first unsupported and simulated high seat shot as comprises the so-called Stalkers Test and “booooom” goes the MB equipped rifle next to me. Well, I do need every excuse possible for missing the 10 ring!

K
 
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