Today I was shooting my 416, getting it and me ready for a lion hunt in less than two months.

The rifle is a Model 70 with Leupold QR mounts. I have a low powered scope in low QR rings for most hunting and my Zeiss 2.5-10x50 IR scope in high rings as my lion and leopard set up.

This scope was previously on a Model 70 in 338 (also on high rings) that was a dedicated leopard rig. The scope came off of that rifle, into QR rings, and on to the 416.

So, with the scope already zeroed from the prior set up, and using high Leupold rings on both setups, I figured the POI would be really close when I made the move to 416.

The first shot, at 50 yards, was 6 inches low. I was surprised, but the left-right was good and I figured that I would dial in the elevation, shoot a couple of more times, and be good to go.

I dialed in 33 clicks of elevation and fired a shot into the bottom of the bullseye. Figuring three or four more clicks would get me to the desired POI, I went to turn the dial and I only had one more click of elevation adjustment.

With that click, I fired again at 50 and 100 yards and all was well, but that fact that I have no more vertical adjustment worries me. Is there something wrong with my set up? What if I need to dial in additional elevation when I get to Zim?

How could the set up on the 416 be so different from the 338? I know the trajectories are different, but they are not 6 inches different at 50 yards!

I'm thinking there is a set up problem here. What are the options?

1. A ring that is too tall or too short?
2. Leupold lever not pulling the scope in tightly enough? (I dismiss this as the other scope is dead on)
3. ????? what else could it be?

Will, you could shim the scope inside the rings with pieces of electrical tape to get you a few more MOA of vertical adjustment, but dead on at 100 with a 416 isn't a bad set-up for Africa.

It may be your Zeiss has a small adjustment range. I have found this with some of the European 30MM scopes. Try reversing the rings to determine if you have a ring problem. I have a Zeiss that is very cranky about which gun it can used on. High rings may be an issue also. It would seem to me the higher the scope is above the bore the more adjustment that is needed for a short range zero.

quote:

Originally posted by Biebs:
Will, you could shim the scope inside the rings with pieces of electrical tape to get you a few more MOA of vertical adjustment, but dead on at 100 with a 416 isn't a bad set-up for Africa.

I was thinking of reversing the rings to see if that changed the POI.

The first Model 70 416 I had always shot low...When I contacted Leupold about not being able to zero their scope they blamed the action being machined wrong and claimed it wasn't the first Winchester they had heard of with the problem. They recommended shims.

Custom bases fixed the problem.

Years later I re-barreled it and just out of curiosity stuck the old barrel between centers on the lathe and checked it with a dial indicator. The barrel was warped "downward" something like 12 thousandths...centered right where the factory welded the lug on.

The new barrel worked great and required minimum adjustment.

All this to say that it might not be a scope problem, so much as a rifle problem, compounded by a scope with less adjustment.

quote:

Originally posted by Ongwe:
All this to say that it might not be a scope problem, so much as a rifle problem, compounded by a scope with less adjustment.

The rifle is a proven performer. I have a low power scope that works great (as recently as today) out of the same bases. The issue really seems to be ring related. Otherwise, why would the zeroed scope hit 6 inches low when I moved it from the 338 to the 416, with high rings being used in both instances.

I've had that same problem with 2 of the newer Remington 700 Actions. You can either use electrical tape to shim the front ring or contact the base manufacturer for a shim or two. It fixes the problem.

The zero for a 338 at higher velocity could result in a lower impact for the 416 at 2400 fps. Similar to shooting 300 gr bullets out of the 338 when it is zeroed for 225 gr bullets.

Apart from that - it might be worth checkin if the eye relief is the same for the two rifle set ups. is it possible to move your scope forward a bit?

Just a few possibilities ...

quote:

why would the zeroed scope hit 6 inches low when I moved it from the 338 to the 416, with high rings being used in both instances.

"why would the zeroed scope hit 6 inches low when I moved it from the 338 to the 416, with high rings being used in both instances."

I keep all my scopes and rifles outfitted with Talley rings and bases and am an admitted scope swapper. Going from one gun to the next, it isn't at all unusual for the point of impact to be off six inches or more. There are just too many variables in the equation.

I'd try reversing the rings first personally.

Ths isn't unusual at all and us the reason brownells sells scope base shim kits. Try one you'll like it. Much less homeboy than using electrical tape.-Rob

Thanks all, but a base shim will throw off my other scope POI and may exhaust the elevation adjustment on that scope. I would basically fix one to the detriment of the other.

I think step one is trying to reverse the rings and step two, if step one does not work, is a shim in the front ring.

Step #2 should be a shim in the BACK ring to provide additional elevation.

quote:

Originally posted by prof242:
Step #2 should be a shim in the BACK ring to provide additional elevation.

quote:

Originally posted by Blacktailer:

quote:

Originally posted by prof242:
Step #2 should be a shim in the BACK ring to provide additional elevation.

The lead foil from dental X-ray film pack makes a good shim.
Cut and fit and layer to proper thickness as needed.
Got a dentist friend?
I did that once. Worked fine.

wine bottle cork covers. I think they're tin. may be too thick.

quote:

Originally posted by prof242:
Step #2 should be a shim in the BACK ring to provide additional elevation.

Thanks.

I shouldn't be allowed to ponder physics, angles, tragectories, and the like before my coffee.

[QUOTE]Originally posted by LJS:
It may be your Zeiss has a small adjustment range. I have found this with some of the European 30MM scopes. ]

The oposite is actually the norm.
30 mm tubes usually gives more adjustment range than 1".
It might also be a bit stronger and more rigid.
Otherwise, the 30 m tube has no adventages over the 1"

Good luck Will. I'm sure you'll get it doped out. I personally like the electric tape solution. Hope you find an old, well-maned shumba.

Remove scope. Then reset scope wind age and elevation to neutral. Remount and try.

quote:

Originally posted by prof242:
Step #2 should be a shim in the BACK ring to provide additional elevation.

I'm sorry.
Shim should go under the base of the rear ring,
not inside the rear ring.
The lead-alloy foil can be cut to fit between the scope base and the rear receiver, and holes punched to allow the base screws to pass through it.
It will be almost invisible.

I have never shimmed inside the rings for elevation adjustment, rather shim under the scope bases.

Get that rear scope base a little higher and the rifle will shoot higher.
Raise the front scope base and the rifle will shoot lower.
You could also use proper thickness of heavy-duty aluminum foil, or aluminum beer can cut with shears and hole punch.
Then start over with scope in neutral/midrange elevation setting.

If you consider the sight radius to be only the distance between centers of the front and rear scope ring, roughly 6",
then it should only require 0.010" elevation of the rear scope base to cause a 6" elevation of POI at 100 yards.
If scope ring centers are closer than 6" between them,
then even less shim will be needed than 10-thou.

Review:

This is a two scope set up. A low power scope for buffalo and general game and the other (a big heavy illuminated number) for lion and leopard.

So, there's no plan to shim a base as that will screw up the scope that's dead on.

Assuming that reversing the rings results in the same POI, what's wrong with a bit of tape in the bottom of the rear ring?

Thanks.

Arild; My experience with slightly older Zeiss scopes has been lack of adjustment and limited eye relief. I have a Zeiss 5x15 that cannot be used on a Sako with Optlock rings. It runs out of windage adjustment. Swarovskis have been OK but Zeiss not so good for me.

Measure the bottom half of the rings to see whether they are identical or not. If not, contact Leupold for replacement.

I don't think that tape in the ring can make enough of a difference in POI. You're compress to compress that tape when you tighten the ring halves together. A plastic shim in the lower half may work; try one cut from a milk jug.

George

Assuming both scopes are good, and one of them does not have a problem with vertical adjustment,
maybe one of them is just more limited in elevation adjustment,
and assuming the front and rear ring bottoms are not mismatched in height,
and assuming the scope mount bases are not mismatched in height,
that points to the action receiver being vertically challenged, like lower at the rear than it should be,
or higher at the front than it should be, so:

You might do better if you get the rifle bases, front and rear, to correct height match where the rings start: shim between REAR base and receiver

Then any setup or combination of scopes would work better.
You will have a greater range of adjustment with both scopes,
and you will be "dead on" with both.
You may have to rezero the other one also.
That might take 3 shots, not a biggie, just fun at the range.
And it will be a more stress free setup on the scope.
Less torque on the scope tube when you torque the ring screws properly.

Shimming inside one ring and not the other ring: not good
Puts a wee bit of bending torque on the scope tube, not stress free.
Git-R-done right.

RIP and I both have suggested the same approach. It's the correct way to fix the probklem and has been done for years by competent gunsmiths.Do you think you'd get a scoped rifle back from AHR for example with a piece of tape or other "stuff" under a scope? Doubt it! It's your gun afterall and you get to do what you want. Best of luck!-Rob

We have had good luck using aluminum foil as shims.

I would stay away from electrical tape and plastic. Use real shims instead.

Electrical tape and plastic can flow after you tighten them down.

quote:

Originally posted by GOB:
We have had good luck using aluminum foil as shims.

+1

My shims are made from Aluminum cans. Measure and cut from a piece of a dry can with scissors, hole punch with a small nail and you're set to go. No rusting, no shifting, no flow. You may need more than one, but the drill is the same for any number needed to be layered underneath your scope base.

Shim in tonight, shoot tomorrow.

Two shims moved the POI to 14 inches high at 100 yards. Adjusted 42 clicks (1 = 1/3MOA) and shot one more into the the 1" bull.

Back to the smith tomorrow to make it look pretty and lock it all down.

Thanks to all for the good suggestions.

Now we wait for the hunting report!

Whatever means you use to fix the problem, the crosswires should finish up near the centre of the adjustment range, even with image-movement scopes (second image plane, as they dissemble it these days). Failure to do this can apparently result in misses caused by differences in head position, which may be beyond a parallax adjustment's ability to fix.

In the case of reticle-movement (first image-plane?) scopes, failure to do this will leave your crosswires out of centre, which is not a good look, to say the least.