Thread: New rifle, scope question

Originally Posted by gadgetman

This relativity only applies to light projectiles going 3x 10⁸ meters per second. For what we're dealing with we just go for 1/2 mv².

I was trying to say that the energy the bullet has leaving the muzzle is the main determinant of recoil going the other way. The reason the rifle is slower going rearwards is that it is 300 to 400 times heavier than the projectile thus reducing speed. If he wants lighter recoil then choosing between identical models of 308 vs 7mm08 (say a T3) then the weight difference between the rifles is negligible, and the energy of the bullet at the muzzle is close enough to identical between the calibres, thus there is almost no difference in recoil between the two. To make any significant drop in recoil, he would either have to sacrifice speed / energy by using lighter loads or make the rifle heavier to slow the recoil.

As a side note, I use the term slow the recoil because the actual amount of recoil in a heavier rifle scenario would actually be the same but the slower transfer of energy to the shoulder will make it feel like less recoil.

Short and sweet. Recoil difference between 7mm08 and 308 is close enough to not matter.

Your eye is inthe right position when you can see clearly though tne sight with no grey/ black blurriness round the edge.

To check its right you bring the gun up to your shoulder with eyes closed . Then open and your eye should be in the right spot. You'll find ideal mounting is a bit further back forstanding anda bit further forward for lying down. (prone).

You'II need to set the crosshairs Vertical too. set sCOpe to lowest power so the image (exit pupil) it big, Then by eye lookup and down the vertical crosshair to check the Vertical hair goes straight toward the center of the barrel ,

most people mount and adjust their Own scopes.

Everything said above... Nice work gentlemen!

Originally Posted by Bagheera

Your eye is inthe right position when you can see clearly though tne sight with no grey/ black blurriness round the edge.

To check its right you bring the gun up to your shoulder with eyes closed . Then open and your eye should be in the right spot. You'll find ideal mounting is a bit further back forstanding anda bit further forward for lying down. (prone).

You'II need to set the crosshairs Vertical too. set sCOpe to lowest power so the image (exit pupil) it big, Then by eye lookup and down the vertical crosshair to check the Vertical hair goes straight toward the center of the barrel ,

most people mount and adjust their Own scopes.

What I do to get mine vertical is put the gun in the soft jaws of the vice and use a spirit level on the top of the bases (or across any flat horizontal surface on the rifle itself) then make sure it is secured in the vice. Once this is done check that the rifle is still level.
(across the rifle, as forward back along the rifle wont matter while doing this, it will be presumed that the scope rings will end up being parralell to the bore)

The while the scope is slightly loose in the rings, use the spirit level to check the turret on top is also level. (as long as it is flat across the top which most are.). Tighten and check level again. Tightening the screws on one side can "pull" the scope over so this last check is definitely warranted.

Originally Posted by timattalon

What I do to get mine vertical is put the gun in the soft jaws of the vice and use a spirit level on the top of the bases (or across any flat horizontal surface on the rifle itself) then make sure it is secured in the vice. Once this is done check that the rifle is still level.
(across the rifle, as forward back along the rifle wont matter while doing this, it will be presumed that the scope rings will end up being parralell to the bore)

The while the scope is slightly loose in the rings, use the spirit level to check the turret on top is also level. (as long as it is flat across the top which most are.). Tighten and check level again. Tightening the screws on one side can "pull" the scope over so this last check is definitely warranted.

Okay that makes perfect sense thank you! Sounds easy enough. Hopefully can get a hold of some tools to do the job soon. Cheers

Originally Posted by timattalon

What I do to get mine vertical is put the gun in the soft jaws of the vice and use a spirit level on the top of the bases (or across any flat horizontal surface on the rifle itself) then make sure it is secured in the vice. Once this is done check that the rifle is still level.
(across the rifle, as forward back along the rifle wont matter while doing this, it will be presumed that the scope rings will end up being parralell to the bore)

The while the scope is slightly loose in the rings, use the spirit level to check the turret on top is also level. (as long as it is flat across the top which most are.). Tighten and check level again. Tightening the screws on one side can "pull" the scope over so this last check is definitely warranted.

Until you get a rail or some rings machined on the piss this will work

There are very few gun shops I would trust to correctly fit a scope. After watching the efforts of a gun shop jockey in GS one day my opinion is only reinforced. He did the whole exercise using a battery drill! Plus how do you set up a rifle and scope for an absentee owner?

In your case due to experience you probably have to hope the gun shop will do the best for you. In this case I would say the guy was “lacking”. Your scope looks too far fwd which will cause you to “crawl” your head fwd on the stock and assume an unnatural position. Getting a smack in the eye is more about not holding the rifle correctly.

The way I set up my scopes is to first decide whether I will predominantly be shooting prone or off hand. For my F Class stuff it is obviously prone and I do the set up prone. For my hunting rifles I go with an off hand setup keeping in mind that prone shots that will still be taken tend have the effect of shortening the distance between my eye and the scope. Sitting at a bench will be similar to off hand. You will never get a perfect set up as you could be taking shots steeply up hill or steeply downhill which changes the relationship between eye and scope. Steeply uphill – beware a “Weatherby eye” may be the outcome. You learn after one experience!

I mount the scope very loosely in the rings. Set scope power to max – this will give the shortest eye relief. With eyes closed raise rifle to shoulder in a comfortably hold. You can rest the forend against something to do this but try to maintain a natural upright position.
Open eyes and check the view thru the scope. Your view should be the full field of the lens. If the scope is too far fwd you will get a reduced circle of view. Adjust scope position in the rings backwards or fwds to get max size of the view. Typically the distance between eye and scope will end up ~ 3.5”/90mm but this will depend upon scope brand/model.

There are a whole heap of other things to be aware of which would require a few more chapters e.g. is the scope held true in the rings/do the rings need lapping? Bad alignment of the rings can damage the scope. Some rifle actions are shockers and the line up between the back and front rings crap, likewise cheap rings can give problems as well. Also need to, once eye relief is determined, set the vertical part of the cross hair plumb thru the bore centre.

Congrats on your new toy as well. I can still well remember my first rifle.

Originally Posted by zimmer

There are very few gun shops I would trust to correctly fit a scope. After watching the efforts of a gun shop jockey in GS one day my opinion is only reinforced. He did the whole exercise using a battery drill! Plus how do you set up a rifle and scope for an absentee owner?

In your case due to experience you probably have to hope the gun shop will do the best for you. In this case I would say the guy was “lacking”. Your scope looks too far fwd which will cause you to “crawl” your head fwd on the stock and assume an unnatural position. Getting a smack in the eye is more about not holding the rifle correctly.

The way I set up my scopes is to first decide whether I will predominantly be shooting prone or off hand. For my F Class stuff it is obviously prone and I do the set up prone. For my hunting rifles I go with an off hand setup keeping in mind that prone shots that will still be taken tend have the effect of shortening the distance between my eye and the scope. Sitting at a bench will be similar to off hand. You will never get a perfect set up as you could be taking shots steeply up hill or steeply downhill which changes the relationship between eye and scope. Steeply uphill – beware a “Weatherby eye” may be the outcome. You learn after one experience!

I mount the scope very loosely in the rings. Set scope power to max – this will give the shortest eye relief. With eyes closed raise rifle to shoulder in a comfortably hold. You can rest the forend against something to do this but try to maintain a natural upright position.
Open eyes and check the view thru the scope. Your view should be the full field of the lens. If the scope is too far fwd you will get a reduced circle of view. Adjust scope position in the rings backwards or fwds to get max size of the view. Typically the distance between eye and scope will end up ~ 3.5”/90mm but this will depend upon scope brand/model.

There are a whole heap of other things to be aware of which would require a few more chapters e.g. is the scope held true in the rings/do the rings need lapping? Bad alignment of the rings can damage the scope. Some rifle actions are shockers and the line up between the back and front rings crap, likewise cheap rings can give problems as well. Also need to, once eye relief is determined, set the vertical part of the cross hair plumb thru the bore centre.

Congrats on your new toy as well. I can still well remember my first rifle.

Perfect explanation, thank you so much! Will see if i can get hold of the type of screwdriver needed loosen up the rings. Will be good to learn and do it myself i guess, how do you make sure the scope is level? as in how can i be sure that the crosshairs arent slightly off to one side?? not worried about finding the right distance, as im fairly sure its just about a cm or two back from where it is now but i want to make sure i have the crosshairs level before i tighten her back up obviously. cheers

Originally Posted by TheJanitar

Perfect explanation, thank you so much! Will see if i can get hold of the type of screwdriver needed loosen up the rings. Will be good to learn and do it myself i guess, how do you make sure the scope is level? as in how can i be sure that the crosshairs arent slightly off tot he one side?? not worried about finding the right distance, as im fairly sure its just about a cm or two back from where it is now but i want to make sure i have the crosshairs level before i tighter her back uo obviously. cheers

If you don't have a level system you can just do it by eye, or, setup a plumb bob and make sure the rifle is as square to ground as possible and aim the scope at the string line.

Originally Posted by Nibblet

If you don't have a level system you can just do it by eye, or, setup a plumb bob and make sure the rifle is as square to ground as possible and aim the scope at the string line.

Sounds simple enough! How tight do the screws have to be? I realise there isnt an exact definition you could give me, but what would your personal "explanation"? haha

Are they easy to strip?

Originally Posted by TheJanitar

Sounds simple enough! How tight do the screws have to be? I realise there isnt an exact definition you could give me, but what would your personal "explanation"? haha

Are they easy to strip?

Personal experience, not too tight....

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Don't get hung up on what it looks like staring at the rifle haha. Different positions work for different people's eyes.

Like zimmer said, depending on your shooting position has quite an effect on how you will sit in the eye box.
If you lie down on the floor in the prone position you might find it's perfect. You'll have to work out what you think your shots taken will most likely be and maybe just get use to pulling it in tight to your shoulder for standing shots to take up some of that creep.

when I bring it up to my shoulder I have to creep my head forward just a tad to get the perfect eye relief (maybe a cm or so). Any opinions on this?

My opinion (not sure of its value)........ if you have to move your head forward then yea the scope is too far forward
Close your eyes shoulder the rifle with your head in your comfortable shooting position .... open your eye, if the scope is in the right spot the eye relief will be right and you won't need to move your head. How far forward to mount a scope is not the same for everyone and some scopes have a long eye relief so if you don't like it or it doesn't feel right move it.

On big recoiling rifles a little bit further forward isn't a bad thing but for the 308 you should have a full view looking through the scope with no head movement. My 338 Win Mag has scope mounted a lit forward for that reason.

Watch a few vids on you tube, this is something you really need to do yourself, it's kind of personal, and you can do a better job yourself.
Next to none of them use a bit of lock tight on the screws, so you need to do it again anyway.