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Franco2shoot

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OK, I labeled this thread like this cuz my heads gonna explode. Here's the story. I have a nice Remington model 7 with a lowend Bushnell Tropyn 3x9. When the store installed the scope the did a poor job , I thought, cuz they had the large thumbscrews on the right side over the magazine making loading difficult. I had them flip the rings and put the screws on the opposite side, and that might well be the problem. You see, last Friday night I went to the Gunshow and bought one of those in the chamber Boresighters. A 308 in my case. When I got home I dropped it into the rifle and while dark pointed it up the street at the Stop sign. The sign is luckily 100 yards away. Now after several boxes of ammo, I thought I had it perfectly sighted in, had I pulled the trigger the hole would have been in the center of the "T" but with the laser on the dot was instead over in the "O", about 270 degrees clockwise or to the "Left" pulled the crosshair over the laser dot. However when I went to the range next day aiming at the bull put the shot over to the left(See the figure).

Ok for the pro's, I know the scope is misaligned but what do I do to correct? Up down is perfect, so do I just put a shim on the right side of the front ring and left side of the rear? Or, forget it.... Right now the bullet hits where the crosshairs indicate at 100 yards.

KKKKFL
 
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I really don't understand your problem. The proof being in the pudding I'd say you've got it dialed right in. The only purpose a bore sighter serves is to get you close, hopefully on paper. You can then fine tune things with the adjustment knobs on the scope. Ditch the bore sighter, forget the sign and shoot paper. I'm not a big fan of them, but it sounds like this one is doing what it was made to do.
Mark
BTW- If your not on paper at 100 yards just move to the 50 yard or even 25 yard ranges.
 
I tend to agree... The scope is dialed in and I have 1 to 1.5 inch groups which for me is OUTSTANDING... I can even observe the difference in elevation between 125 grain and 165 grain and maintain the same grouping... but then there's that nagging academic side of my brain that keeps asking Why... the light beam is perfectly straight, and straight down the barrel... could it be walking to the left due to the spiral? That's why I said for Pro's.... my head hurts thinking about this.
 
but then there's that nagging academic side of my brain that keeps asking Why... the light beam is perfectly straight, and straight down the barrel... could it be walking to the left due to the spiral? That's why I said for Pro's.... my head hurts thinking about this.
Click to expand...

Because that light beam is not perfectly straight down the barrel. Put a cleaning rod down the barrel. You can wiggle it a bit. Even if its only a hair, that is a lot if you carried that line all the way out to 100 yards.
Now I am not saying the laser is wiggling around in the chamber, just that there is room for the laser itself inside the brass to be a bit crooked.
 
The answer is that the light beam is perfectly straight, but it's NOT perfectly aligned with the barrel.

Try this...

Take the bore sighter and turn it 1/2 turn and put it back in.

Did the dot move? Of course it did.

The manufacturing tolerances allow for a tiny amount of "mistake" when they make things.

If that bore sighter was absolutely perfect in every way, it would cost a fortune.
 
When you turn rings around, the boresight can change... that is normal.
Never confuse a bore sight with a zero. Boresighting only helps you get to your zero faster. If your gun is zeroed, there is no problem. You are ahead of the curve. Now rezero that .308 for 200 and your shiny.
Instead for worrying about the boresight - worry about that crappy Bushnell. Go ahead and start planning on that upgrade as soon as you can. At least go get a Leupold VX-I for that Remington when you can swing it.
 
go to midway usa. look on their video section. there is a link on bore sighting and sighting a scope on a rifle
 
The difference between boresighting and shooting is the rifle moving during the shot. If you had a perfect laser boresighter and had it perfectly centered on your 100yd target, you would NOT hit exactly there.

When you pull the trigger, a whole series of dynamic things begin happening. The rifle begins to move as the bullet starts down the barrel, the barrel bends and deflects with the stress of the bullet being forced into the lands and the whole barrel/receiver squirms in the stock.

NO boresighter will ever get you dead-on perfect at 100yds. As others have said, their purpose is to get you on the paper so you can make the final adjustments which account for all the mayhem during the firing sequence.
 
NO boresighter will ever get you dead-on perfect at 100yds.
Click to expand...

That's the real deal. My boresighter gets me on an 8 1/2 x 11 sheet of paper at 100 yds. The rest is bullets and knobs.
 
Franco;

Since you've got a Remington model 7, bolt action gun, do this: Remove the bolt, and mount the gun in a steady rest. Make sure the gun isn't canted to one side or the other. Prepare a common paper plate by putting a 1" dot in the center. Tack the plate up about 25 yards away. Run a plumb-bob string down the plate across the dot. Close is good enough. \

Now, look through the barrel, get the dot visible when looking through the barrel. With the dot visible in the barrel, look through the scope. Adjust the scope to match the barrel. Don't scratch the head too hard, it's gonna be backwards. Your matching the scope to the barrel in this instance, not t'other way around.

Bingo, you've bore sighted good enough to get you on paper at the range.

900F
 
Good answers, all... as for the dot moving with each insertion of the laser(which was my initial guess) that doesn't happen. I put a scratch on the back and have twisted it 45/90/130/270 degrees around and despite this the dot is always in the same displaced spot shown in the figure above. This would dispel the wiggle room argument or laser not exactly centered.

I'm thinking George has the answer with purchase of a new scope as the both the best long term SOLUTION, as well as answer.. The internals of a low end scope are probably not up to the laser test. If the objective lens is off by a mere millimeter it could be the reason for the mis-match.

I would sure like to hear from someone out there that has experienced the same offset or a similar one... just remember this is the boresight that comes in the cartridge size of your rifle, not a multi-calibre one...

KKKKFL
 
RecoilBob is dead on. NO boresighter will zero your rifle, no matter how perfect it is. Put a $3000 Swarovski scope on it, and use a perfectly aligned boresight laser, and you STILL will not zero the rifle in using the boresighter alone. The sole purpose of the boresight is to get you close enough to hit somewhere on the paper at the range. You then use the adjustment knobs on the scope to zero the rifle in. Then even after you have the rifle perfectly zeroed, if you change ammo brands, bullet weights, or whatever, you will have to zero the rifle all over again.

Right now the bullet hits where the crosshairs indicate at 100 yards.
Click to expand...

If your bullet hits where the crosshairs indicate, then there is NOTHING wrong with your scope or your rifle. Everything is working as it should. The fact that the laser does not point to the same place as the crosshairs after you zeroed the rifle is completely irrelevant. A bullet is not a laser beam. The rifle, as RecoilBob pointed out, is moving about as you fire it, and a bullet flies on an arced trajectory, influenced by wind, ambient temperature, humidity, barometric pressure, and gravity. Lasers are not affected by any of those things.
 
Throw the stupid toys away(or better yet get your money back) and just shoot the dang thing----bore sight the old fashioned way and you'll be fine.

A better scope wouldn't hurt either.
 
chambers are not all made to the same specs , what might work in one ,might not in the next , wear an tear is another factor ,use it to get on paper ,the rest is shooting it in ,good luck
 
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As I re-read all the comments (and from a practical point I agree with all of them) one thing did stand out. Not one respondent ever addressed whether the scope/rails/rings were mis-aligned left or right.... As I stated up/down is spot on, I mean the red dot is split in half by the cross hair. From a purely academic point... is the scope tube pointing to the left or right when viewed from above given the picture posted in post#1?

KKKKFL
 
Franco,

You're worrying about how many angels can dance on the head of a pin. Let it go, and SHOOT your rifle. The proof is on the paper.

Any bore sighting system is only intended to get you 'on paper,' or close enogh so you can do a final zero with live fire. Bore sighting is NOT a substitute for a live fire zero. Bore sighting is not 'better' than a live fire zero, even though your bore sighting system involves a gee-golly-whiz-bang too cool for school oh so modern laser.

If your rifle is now zeroed, then the scope tube is pointed reasonably well in parallel with the bore and not to one side or the other, or up or down. The adjustment happens when you move the reticle, not the scope tube. It matters not which direction the thumb screws are pointed, as long as the rifle/scope combo takes and maintains the zero you want.

HINT: Reticles in scopes (more often less expensive scopes) don't always move when you first click in adjustments. Sometimes they stick, and then shift upon recoil from the next shot you fire (in other words, your first shot with an "adjusted" scope will go where it was originally 'looking' before you adjusted it). I usually whack the buttplate/recoil pad lightly a couple of times with a rubber hammer after clicking in scope adjustments to simulate recoil just in case the reticle is sticky.

HINT 2: Save up for a better scope. Make sure all the base and ring screws are uniformly tight when you mount it.

HINT 3: If you plan to hunt with your rifle, zero it about 2" or 2 1/2" high at 100 yards.

lpl/nc (not a professional, I do this for free :D)
 
Re-doo attachment

I have no idea why the attachment dropped out here it is again:
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And I've stopped trying to figure out which way the tube is mis-aligned, it hurt my head too much...

Besides, I can hold a nice pattern at 100 yards with the Trophy, and I found a really good deal on a better scope..(see below)
Barska 3-12x40 Tactical Riflescope AC10772. With this Barska Riflescope, Barska has turned tactical into practical. The Barska 3-12 x 40mm Tactical Riflescope AC10772 is designed to give you as as much control as possible for extreme-type shooting at a practical price. This Barska 3-12x40 mm Tactical Riflescope AC-10772 offer some of the most sought after features like side adjustable parallax adjustments and first focal plane Mil-dot reticle that allows you to estimate range at all power settings.

KKKKFL
 

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Oh God, now you've done it! The scope snobs will decend on you like a pack of wolves, telling you you have to spend $500.00 on a BASIC scope. They'll also tell you to stick with the Bushnell over any Barska. I think you're making mountains out of molehills. Forget the laser. That laser isn't doing the downrange work, and isn't gonna put one venison steak in your freezer, the bullet, which you say is going exactly where your scope is telling you it's going is...
 
hahahah
I enjoyed that response... and +1 to the meat in the freezer, just remember I was talking the Academics part that Gunsmiths tinker over(crooked to right or left)... at this point, since so many have taken the "Its on the Paper - forget the academics" response, I'll tinker with the current set up to see if I can answer my own question, but only after I have a new scope/ring set-up arrives in the UPS guys hands at my front door.

Thanks to all that responded - I'm still thinking about those angels on the pin...

KKKKFL
 
One more thing to think about though, that barrel was drilled and rifled before it was put into another machine to have the chamber cut and reamed. That second or third machine CANNOT POSSIBLY be alligned exactly with the machine that drilled the blank, or the one that rifled it, so though the barrel is sending the bullet to one spot, the chamber is probably misalligned a 1/10 minute or so of angle, which would explain your differences quite handily.
 
Remove the bolt, and mount the gun in a steady rest. Make sure the gun isn't canted to one side or the other. Prepare a common paper plate by putting a 1" dot in the center. Tack the plate up about 25 yards away. Run a plumb-bob string down the plate across the dot. Close is good enough.
Click to expand...

CB has a great method here.

I especially like the vertical string, weighted by a plumb-bob, to align the scope's crosshairs with a true vertical.

That's something that a laser boresighter won't do.

I don't own one, and never had a need for one before. With this new trick I picked up here today (thanks, CB900!), I have even less need of one.
 
Franco;

Remember that the Remington is a production grade rifle............... More than likely it's the screw holes on the action, OR, the threading of the shank of the rifles barrel, (and/or the action).

You can "FIX" all these problems. Here's how.........

Have a gunsmith weld up the mounting screw holes, and then set up the action in a line-boring fixture. Recut the threads in the action and true the action face to the threads in the action. Then, re-drill the mounting holes for the scope mounts. Get a set of custom bases such as the Warne's. Then, have the gunsmith lathe-turn a barrel blank in your chambering, (cartridge of your choice) and thread the blank on the same lathe.

Then, ream the chamber with the action/barrel still mounted in the lathe.

Then, mount your "high dollar" scope of choice..... It dosen't really matter which, as long as it's over $1,000.00 as you already have over $3,000.00 invested your "Model-7"

(FWIW; My brother wasted several "once in a life-time" biggame tags on his Bushnell "Trophy" scope. After the third one lost zero and cost him a nice elk in Colorado, and a nice 10pt buck and 7rds wasted on 3 does before he figured out it too had a detached reticle...... He finally spent an additional $150 over the original cost of the Bushnell on a Leupold. Three shots; a trophy elk, a trophy mule deer, and a trophy pronghorn antelope, he's decided that the Leupold is the "cheapest" scope you'll ever buy...........)

When you're finished, you'll then be able to put your ~$30 laser bore sighter in the chamber and have it then "approximate" the POI/POA.

Worth it???? Of course not !!!!!!! That's why you have to "live" with the tolerances of "production" grade rifles.


I had/have an Interarms MkX Mauser. It came in .30/06. With Leupold Vari-X II scope on Leupold rings and bases, it wouldn't hit within 1' (feet) of the "bore sighted" spot at 50yds. The iron sights were run all the way to the left with the front sight and right with the rear sight to get it " on the paper" at 25yds.
However, it was the MOST accurate .30/06, or any .30cal I've ever owned (I've had a BUNCH). I replaced the barrel with a custom .338/06 barrel. It hit almost to POI/POA with the initial bore sighting, everything else is the same. However, the gun won't group better than 2moa........... It's all in the barrel. (I still have the original barrel BTW).

Most of the barrel manufacturers will straighten a "crooked" barrel. This results due to variations in the metal in the barrel, and a "jillion" other variables (including stress relief, and warpage during heat-treating after machining). Savage/Stevens has one person in their barrel division that does nothing but check the barrels for "straightness" and "straightens" the "crooked" ones by various means. (bending, heating, ect......).

The Remington M-7 has a very light weight contour barrel. (I have two...... I know.....). As such it will have such "idiosynchrysies". It has a double whammy....... factory "run of the mill" and light-wt contour. Both spell potential trouble. Many gunsmiths make a good living by "blue-printing" factory actions... (read: M700 "custom" rifles with "match grade barrels"). Both my M7's wear "Leupolds" BTW. Both were picked up "used" at about 1/2 the cost of a new one. In fact, all my Leupolds have been "second hand". Only one's had to go back to Leupold and it was my fault for letting it fall 30' out the door of the shooting house............ But I digress.......

Both my M7's have their "foibles". But, I dearly love them as they have numerous attributes that are otherwise only available "together" in custom rifles costing many times more money......
I'll settle for both giving sub-moa accuracy with one or two specific loads.

Just do as most of the others have said...... Just go shoot that thing and be happy !!!!!!!! And toss that laser bore sighter in the gear bag and make a note of where "zero" is when it's installed.... That's all they're good for anyhow.................
 
I am amazed that in all of this post no one has mentioned the obvious.Beams of laser light are straight and true.Bullets come out of a harmonically vibrating barrel and the bullet doesn't go exactly where the bore is pointing.That is whu you have a variable feature to the cross hairs of a scope.To make the rifle scope look where the bullet is hitting.

Stan
 
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