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View Full Version : Shim Scope Base for more Elevation??



Ingwe
04-30-2011, 01:38 AM
The rifle is a M 12 VLP in 204 Ruger, the scope (on order!) a Vortex Viper 6.5x24x50. One piece base with no elevation built in.

Approx. at what range will this set-up shoot until I run out of elevation?? That's my main question...

I will do allot of shooting at 100 yards so that's why I went with the level base...I was told that a 20 MOA base would shoot high at 100 yards.

I am thinking that a compromise would be a thin shim (under Rear end correct??) but want to hear your opinions.

What I want to hear first is how far out the gun could be expected to shoot the way it is!

Thanks Fellas!!

KRP
04-30-2011, 01:40 AM
You're going to have to mount the scope and see how much adjustment you have left after zeroing.

Ingwe
04-30-2011, 02:01 AM
I was afraid that that would be the answer only because I live (unfortunetly!) just outside of New York City and I don't have easy access to range past a few hundred yards.

That's why I just want to set it up without tinkering too much with it...I have no idea when I'll be able to shoot past 200 yards or so. Maybe it won't be until I hunt prairie dogs later this year.

A guess on my max yardage as is with flat 1 piece base?

earl39
04-30-2011, 02:18 AM
You're going to have to mount the scope and see how much adjustment you have left after zeroing.

+1

As for a guess If you get lucky and scope is centered when sighted in at 100 yards with a total of 68moa of adjustment ( i used the 6.5-20x50 viper) you should be good to go as far as you want to shoot that little 204.
This was figured with factory Remington 40gr AccuTip-V Boat-Tail ammo. Chart shows about 26 moa needed to get from 100 yard zero to 1000 yard zero. You would be almost topped out on adjustment tho.

Hope this helps.

Gary

KRP
04-30-2011, 02:34 AM
Without mounting the scope and zeroing you don't know how much adjusment you will have available. The 68 minutes of internal adjustment that scope has will get you way,way,way past the realistic range of a 204...if it's mounted so you can use them. If a good portion of the adjustment is available you could dial to 1000+ yards.

SMK Shoe
04-30-2011, 03:45 AM
Also could use the burris signature rings with inserts. getting a set of the off set rings would allow you to either come real close to being zero'd with the scope reticle centered or put alot up into it. just a idea. ( if you've never used the rings, they are great. plastic inserts in the ring never mar or scratch the scope and super solid.)

pdog06
04-30-2011, 07:46 AM
Also could use the burris signature rings with inserts. getting a set of the off set rings would allow you to either come real close to being zero'd with the scope reticle centered or put alot up into it. just a idea. ( if you've never used the rings, they are great. plastic inserts in the ring never mar or scratch the scope and super solid.)



BINGO!!!! Burris Sig Zee 30mm rings w/the +10/-10 inserts in them should give you somewhere around 40moa of elevation left to use(pretty sure one of mine is setup this way, and thats what I had left).

Shimming just the rear of a base could put a bind on the base and/or the scope tube if not careful, so I wouldnt recommend it.

With a 204 you are really gonna battle the wind so it isnt really an ideal 1000yard caliber, but this setup will give you enough elevation to get it there if you choose to.

You could also just simply switch to a 20moa base, like an EGW or similar.

GaCop
05-13-2011, 07:46 AM
I ran into an elevation problem with my Viper in Millet, medium high, windage adjustable rings on a 0 MOA EGW base. All has been well shooting at 100 yards (only distance availaible at the range I shoot). I worked up a good 140 grain A-Max load for my 6.5 Lapua that I'm going to use in a 600 yard match. I ran trajectory tables and found I needed 50 clicks up from a 200 yards zero (1.9" high from 100 yards). I then went to adjust the elevation 50 clicks and found I had only 10 clicks left! I'm assuming my problem is the Millet medium rings have the scope sitting too high and a 0 MOA base?

It looks like my problem solver will be 30mm Burris ZEE rings with a +10 insert in the rear and a -10 in the front along with a 20 moa base. Does this sound right?

helotaxi
05-14-2011, 06:14 AM
GaCop- I'd try it first with just the new Burris rings with the 0 inserts and then add the offsets one at a time if more adjustment is still needed. With the rings 6.5" apart each 0.010" of offset equals 10MOA. If the rings are closer together, the offset equals more POI shift and less if farther apart. If you still need more after adding both inserts, then get the 20MOA base. I just got a Weaver base that I actually like better than the EGWs that I'd been using.

The issue with shooting a .204 at extreme range is the relatively crappy BC of the bullets thanks to the lousy sectional density. First with a 10 MPH x-wind, drift is horrible. Secondly, I'm not sure about the transonic stability of most .204 bullets, but you would quickly find out somewhere between 600 and 750 yds with a 40gn V-Max at a 3800fps MV.

hcpyro13
05-14-2011, 06:54 AM
Which side of the city do you live on? Range 14 at Fort Dix in NJ is 200yds and not a far haul from the city itself. It's not my favorite place to shoot, but decent public ranges are almost nonexistent on the NJ side of the city.

-J

pdog06
05-14-2011, 09:27 AM
It looks like my problem solver will be 30mm Burris ZEE rings with a +10 insert in the rear and a -10 in the front along with a 20 moa base. Does this sound right?


FYI, if you use the offset inserts you have to use a +10 and a -10 in the same ring. You cannot use a +10 or -10 and a 0 in the same ring.

I'd use the -10 in the front bottom(along with the +10 in the front top). Then you can also use the +10 in the rear bottom(along with a -10 in the rear top). This should cant the scope approx 20moa(depending on ring spacing).

The fact that you currently only have 10 clicks left @ 100 makes me question whether your current rings are the same height. That scope has 68moa of adjustment, so I'd thought you'd still be able to get to 600 w/a 6.5L. With everything being a 0 cant I woulda thought you should have somewhere around 20-25moa of adj left(atleast all mine have been that way). Strange

GaCop
05-14-2011, 01:21 PM
I assumed the 68 MOA of adjustment was total up and down so from a setting in the middle range of clicks I should have 34 clicks up?

helotaxi
05-14-2011, 01:32 PM
Yeah, the 68MOA is stop-to-stop, not mechanical center to stop.

GaCop
05-14-2011, 01:34 PM
That's what I thought.

pdog06
05-14-2011, 09:23 PM
I assumed the 68 MOA of adjustment was total up and down so from a setting in the middle range of clicks I should have 34 clicks up?


Are you talking "clicks" or moa adjustment"?

The 68MOA is the total adjustment range, but I also mentioned that with everything currently being at a 0 cant you should probably have somewhere around 20-25 MOA of elevation left(depending on scope height), which is 80-100 clicks.

middle of the road to 68moa is not 34 clicks. It is 34MOA, or 136 clicks on this particular scope.


The fact that yours only has 10 clicks of elevation left in it(or 2.5MOA) tells me that either the scope is extremely high off the barrel, or the front ring is taller than the rear(unlikely though). Hopefully the new rings will fix this for you though. If nothing else it will bring you back to center.

Weird. I've never seen a scope with that much adjustment almost maxed out like that. Dang, A Bushnell 4200 or something like that wouldnt even be able to be zeroed @100 with that setup.

helotaxi
05-14-2011, 10:22 PM
Depends on the model of the 4200...some are really limited on adjustment but I have one with 80MOA.

I've got a Marlin with serious issues in that regard. Used every iota of adjustment on a Vortex Viper with 96MOA of total adjustment to get it zeroed at 100 yds. Initially had it in a DNZ mount but had to move to a rail that would let me use Sig Zee rings. Still was all messed up with the 0 inserts installed (so it wasn't the DNZ mount). I installed the 0.020" offset this week and just need to get it to the range to see if that's going to be enough. I honestly think that the barrel is in the receiver crooked.

GaCop
05-15-2011, 06:10 AM
Each click at 600 yards translated to 3/4" of adjustment so I needed 50 "clicks" to theoretically get me on at 600 yards with the load I used.

The objective of the Viper sits about 3/4" above the barrel in the medium Millet rings. I believe the 20 MOA base and Signature Zee rings/inserts will get me where I need to be.

GaCop
05-25-2011, 07:43 AM
Mounted the base and rings yesterday, 20 moa base and Zee rings did the trick. I now have more than enough elevation on the Viper.