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Scope housing touching barrel..?

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27 October 2009, 00:53
AB Joint Outfitters
Scope housing touching barrel..?
I was installing a 44mm objective scope on my .300win that was wearing a 40mm previously and found that the front housing barely contacts the barrel. It seems that the scope tube lays flat in the rings and contacts the bottom of the front ring like it should. When I move the scope forward so that it doesn't contact the barrel it moves it away from a comfortable position to develop a sight picture with out a halo.

Is it ok to have the scope housing touch the barrel? My inclination is to get higher rings, but I am not an expert on the subject.









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27 October 2009, 01:08
craigster
No, you definately do not want the scope making contact with the barrel. Get a higher set of rings.
27 October 2009, 01:14
wildboar
Of course a good advice; BTW, I've personally seen the bell of a Leupold scope that was been ground a little by a so-called gunsmith to make some clearance with the barrel Eeker
27 October 2009, 01:20
Boss Hoss
There have been a lot of questions posed that were obvious but this one is right up there at the top! Roll Eyes
27 October 2009, 01:45
AB Joint Outfitters
Thanks Boss Hoss. Good to see that you know more about mounting scopes than I do.


____________________________
"Healthy is merely the slowest possible rate at which one can die"

"Men don't change. The only thing that should surprise a man in his life is the history he doesn't know." Harry Truman
27 October 2009, 02:07
Doc224/375
If one is fond of the rings and scope you could always shim the bottom ring .

I know what people are going to say . However if your careful and only shim absolutely what's necessary.

DO BOTH front and rear so as to keep the scope parallel with your bore it works just fine .

I ran into that problem on a couple of my rifles and the next ring height was to high as it lifted my

cheek off the stock . So I shaped a couple of shims and loctited them onto my lower rings .

Never hurt anything never moved under recoil, so what's a few thou going to hurt .005" ?.

Now I'm not talking spacing .125" either !. archer
27 October 2009, 02:16
Recoil Rob
I had one last year that did not touch, I could see light, but I couldn't get a piece of printer paper in there, that's how close it was.
I asked here and was told that as long as it doesn't touch I was OK and I believe it. However one member brought up the scenario that with such close clearance it it would be easy to get a small piece of dirt or leaf or bark to get lodged in there and I would never notice it. Could be just enough to change the POI so I changed out the rings.
27 October 2009, 03:02
merlinron
recoil rob,
good thing to change them out, if they were that close, the recoil was probably banging the bell on the barrel,.... worse than constant contact.

to all......
if you do end up trying shims in the bottom of the rings, cut them only about 2/3 of the ring(1/2 the diameter) long ...i.e. for 1 inch tube about 9/16 inch long. that way you still have the full diameter across the split and you won't squeeze the scope tube too hard.
27 October 2009, 03:13
Alberta Canuck
If I was going to use shims in this circumstance, I would not use them inside the rings. I would put the shims under the base(s).

I would also make them the full length and width of the base(s).

And I would use shims thick enough to give me at least .020" clearance between the scope bell and the barrel...probably more like .030".

Barrels whip, vibrate, wriggle, and temporarily expand as the bullet passes through them. How much probably depends on the bullet and the barrel, as well as a hatful of other things. Anyway, with that much clearance, I wouldn't have to worry about contact...which is what I would be using the shims to avoid.


My country gal's just a moonshiner's daughter, but I love her still.

27 October 2009, 03:39
tiggertate
quote:
Originally posted by Alberta Canuck:
If I was going to use shims in this circumstance, I would not use them inside the rings. I would put the shims under the base(s).

I would also make them the full length and width of the base(s).

And I would use shims thick enough to give me at least .020" clearance between the scope bell and the barrel...probably more like .030".

Barrels whip, vibrate, wriggle, and temporarily expand as the bullet passes through them. How much probably depends on the bullet and the barrel, as well as a hatful of other things. Anyway, with that much clearance, I wouldn't have to worry about contact...which is what I would be using the shims to avoid.


+1 as a rule of thumb. Always shim the bases first and rings as a last resort (my opinion and worth what it cost) but being the curious fellow that I am, I'd shoot it first before I went to all the trouble.


"Experience" is the only class you take where the exam comes before the lesson.
27 October 2009, 05:17
SR4759
You could do like Bubba does.
I have seen 2 rifle barrels with a flat ground on them to clear the objective bell of a scope.
One was a .22-250 barrel from a 700 Remington Varmint and the other was a .30-06 barrel from a .760 Remington pump......
27 October 2009, 11:53
eagle27
Yes I ground a small flat on the barrel of my Schultz and Larsen 7x61 to clear the objective of the steel Kahles 6x scope I mounted in the lowest Weaver 26mm rings (I think the Weaver rings were only available in low for 26mm scope bodies). The 60 degree lift on the bolt of the S & L let the scope be set perfectly low and balanced. Had the rifle for years so was happy to do the little mod job on the barrel which when the bluing was touched up was hardly noticeable.
27 October 2009, 14:47
scubapro
quote:
Originally posted by AB Joint Outfitters:
I Is it ok to have the scope housing touch the barrel? ]


no, absolutely not OK - You need higher rings...


life is too short for not having the best equipment You could buy...
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27 October 2009, 17:38
Hot Core
quote:
Originally posted by AB Joint Outfitters:
...When I move the scope forward so that it doesn't contact the barrel it moves it away from a comfortable position to develop a sight picture with out a halo. ...
Hey Alex, Nice flicks of the issue.

The above sentence indicates you may actually need to shorten your Stock. It could be holding your head too far back and creating the problem.

Or, perhaps the Eye Relief is a bit too short on this particular scope for use on this rifle.

When I mount Scopes for "me", I put them as far forward as possible. In fact, I'd have had that front mount reversed so the Scope went even farther forward and used it at the Rear if possible.

A good many years ago I was watching a rather nice(aka WHOPPER TROPHY) Buck for about 20min right before and after the beginning of Legal shooting time. Had been trying to figure this old boy out for the better part of a year and didn't want to "avoid" taking a shot.

He was almost ready to move into his bedding area, so time was getting short. All I had was an Off-Side(Lefty shot for me) shot opportunity. As I looked through the scope, I noticed the Eye Piece was fairly close. Roll Eyes nilly But..., it was finally an opportunity at the Swamp Master. Decided if the Scope did touch me, it would be the lightest of Maidens kisses. animal

So, it was time to Blast away. BOOM CRYBABY Smacked me like George Foreman. Swamp Master had a small stream of Vapor rising from two holes punched through both shoulders by a 200gr Original Fred Barnes masterpiece of a Bullet. Felt some sweat running, but it was Red sweat. Eeker Got him drug into the back of the truck and when I got to the house, my buddies wife nearly fainted when she looked at me.

Those "slight" Magnum kisses to the forehead tend to bleed right well. Wasn't a big spot, but it was trying it's best to act like I'd fell onto an ax.

And that scope was as far forward as I could get it, with a HUGE Leupold Eye Relief. Just the strange position caused it. Had it been mounted like your scope, it might have done some serious head-whamming.

However, you should always mount a scope the way you like it. Just want you to be aware of a potential head-busting issue.

quote:
Originally posted by Alberta Canuck:
...Barrels whip, vibrate, wriggle, and temporarily expand as the bullet passes through them. ...
I agree with AC's comments. As close as Alex has his scope mounted to the Front Ring, there is less opportunity for the mass of the Objective Lens to begin a large vibration swing, but it will also vibrate independant of the Barrel Harmonics.

I'd guess the Scope life would be pretty short due to the hammering between the Objective Lens and Barrel making contact.

Best of luck to you Alex.
27 October 2009, 18:21
daniel77
For those of you who have never seen this video of a scope flexing...

http://www.youtube.com/watch?v=s5pVya7eask

Granted it is a 50bmg, but the same must be true of all recoiling rifles to some degree.




http://dauphinhorsemanship.com/
27 October 2009, 19:01
jeffeosso
higher rings, or the barrel will bounce off the scope under recoil, damaging the scope .. if its TOUCHING its going to bend


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
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What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
27 October 2009, 19:22
AB Joint Outfitters
Good info guys.. Thanks.


____________________________
"Healthy is merely the slowest possible rate at which one can die"

"Men don't change. The only thing that should surprise a man in his life is the history he doesn't know." Harry Truman
27 October 2009, 21:39
Westpac
Here's a tip, if the scope is so close to the barrel that you have to check the clearance with a sheet of type paper, give it up and go to the next higher rings.


_______________________________________________________________________________
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28 October 2009, 00:27
gunmaker
Most M70s have the front ring closer to the center of the receiver ring. If your scope has such short eye relief that it has to be that far back, it might end up whacking you in the eye between. Maybe you're holding your head back from previous whackings?? Make sure you set up your eye relief for hunting situations at the power settings you would normally shoot with if this is a hunting rifle. If you think you're too close to the scope then buy one with longer eye relief. Leupold has some of the longest.


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28 October 2009, 04:18
Mark
quote:
Originally posted by wildboar:
Of course a good advice; BTW, I've personally seen the bell of a Leupold scope that was been grinded a little by a so-called gunsmith to make some clearance with the barrel Eeker


Hey, I saw a Stainless Ruger Mini-14 that had a good 1/8" ground out of the barrel so the scope would clear! Of course, it was a 6X18 or something with an adjustable objective.


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