Ivey/VGM adjustable bases - anyone used them?

[PeterPHWS]

I am considering the use of an external base elevation system for my .375CT to enable me to use a scope with a higher magnification range but lower internal elevation adjustment and wonder if anyone on here has tried the same ?

From looking at what is available these two contenders seem to be the main options :-

http://www.iveyshooting.com/

http://vgmount.com/

There are posts on this site about the vgmount which are favourable but they mainly come from the use of .22lr through to .308 level calibres.Having some feedback from heavier recoil rounds would be very helpful because the issue of repeatability under recoil is what concerns me.

The vgmount has been used with success in long range pistol comps and given the rifle calibres used there and the way those pistols will recoil it does look to be a capable system for the .375CT if used properly.

I say "used properly" as both systems require "hand tightening" of nuts to lock the elevation change down before firing.

The vgmount utilises a simple "pre-set" gantry mount change which you can adjust to your given round(s) so that a fast "come up" to a known fixed point can be achieved with finer tuning being done using the scope. The fixed points are 5 or 10 in number depending upon the model and can vary from -5 to 110 MOA and anything in between.

There seems to be less reported use of the Ivey system but this offers up to 150 MOA adjustment with 1 MOA graduations and 5 MOA per turn.

However, the web site on the Ivey system seems to be lagging behind his developments and a new SRT30-160 system is available with 160 MOA adjustment with a better 20 MOA per rotation as reviewed here :

http://pmdatabook.wordpress.com/2008/12/21/around-the-industry-ivey-designs/

This last system from the photo's in the review looks to be very impressive.

Naturally though the "user" feedback from guys on here who may have experienced these with high recoiling rifles would be a much more valued "feedback". They both cost over $500 so making a purchase which does'nt turn out good is also important.

Any field use comments as to robustness and retention of zero would also be great.

For those wondering why I am considering these as oppossed to the usual formulae of a straight 20 or 30 MOA incine rail and a good internal adjustment scope such as the NXS 5-22 X 56 the answer is that I mainly shoot around the 40X power in F Class and feel that at ELR the extra power on the scope would be of benefit. The thing is though that you don't know until you try ... so for those who might be able to shed a little light on this all information would be welcome.

 

[excaliber]

Re: Ivey/VGM adjustable bases - anyone used them?

My friend has the Ivey ring-base combo on his 408 Cheytac. They work good but you better bring a notebook to keep up with dialing the Ivey-ring-bases and then also the scope. I thought about a set for my 408 but I am just gonna go with a 1 degree base and Vortex razor scope which has about (roughly) 46 mils total using turret and reticle and I can keep my scope on 20 power.

 

[PeterPHWS]

Re: Ivey/VGM adjustable bases - anyone used them?

That is good to hear ... and I take your point about keeping track of the two elevations ... although the STR30-160 from the pic's in the link has a set of graduations stenciled into the rear mount to let you know what it is set on ... which helps when the rifle has been put away for a while.

Any chance your friend might agree to exchanging some insight into using them ? I am interested in how fast they can be dialed in and how they feel height wise in terms of shooting position.
They seem to increase the height the cheek piece would need to be raised by quite a bit and wondered how they felt "crick in the kneck" wise if you were in position for a while.

 

[excaliber]

Re: Ivey/VGM adjustable bases - anyone used them?

I will tell my friend to get back with you. I think you have to turn it past what you need, then back on what you want. Correct, it is a very high setup, not to uncomfortable, but different.

 

[memilanuk]

Re: Ivey/VGM adjustable bases - anyone used them?

Very interested in this topic! Been eye-balling both these systems - more the VGM than the Ivey, but open to either one - for some time. Now that I have a couple long range rigs capable of shooting further than I have scope/base elevation for... any real-world use info would be great!

 

[PeterPHWS]

Re: Ivey/VGM adjustable bases - anyone used them?

Many thanks for the help excalibur ... and in anticipation to your friend too ...

Memilanuk, if I glean anything which is'nt posted in the thread directly I will share it here.

Looking at the two systems simply through an understanding of how they work ... the VGM system from the video on his sight would move quicker between set increments than having to dial in elevation in 20 MOA rotations ... both are deemed very accurate engineering wise ... but the Ivey system has 50 MOA more available.

As shots at ELR are basically "composed" and take a bit more time than known distance shooting ... I am inclined to think that the speed aspect between the two might not be too critical but having said that I think it is a very useful thing to have.

One big advantage though with the Ivey system is that you can dial in the elevation without having to pre-set the mounts to known "come up" positions ... so you're not having to take the scope on and off to fix the pre-set inclinations ... apparently you have to do this on the VGM as they suggest quick release mounts for this purpose ... and in turn this would mean quite a lot of range time ... especially if you were changing altitude having "set" the system ...

For this reason my immediate preference is towards the Ivey rings as once zero'd at 100 yards the come ups can be entered using information from your balistic software and kestrel meter to cater for such changes without having to "test shoot" to see where the fixed point at say your sea level 600 yards had moved to ...

Again this is all just "theory" from a basic understanding of the two ... but it seems to be "logical" theory at first impressions so to speak ...

 

[Dylanss180]

Re: Ivey/VGM adjustable bases - anyone used them?

I have and ivey base I will give my .02 cents.

I put it on a .50bmg and then swapped it out on a .338snipetac. The first thing you need is an adjustable cheek rest. The rings are extremely high and even with an adjustable cheekrest you will have to modify it just to get it high enough just to be able to see thru the scope.

I also plotted out a calibrated moa scale for a certain distance (I am an engineer and have resources to make such scales) and I checked what the scope base moa adjustment was vs what it actually was. Basically it wasn't even close to accurate. To put it in a nutshell the more adjustment you use the worse it gets (over 20 moa off near max adjustment). I had to keep a chart with me just to be able to use it.

With shooting it on both the .50bmg and .338 it is a very solid mount and functions repeatedly. It is just repeatedly off every time. So if you don't mind having to figure out what you have to set the scope mount to every time then I say go for it.


I am thinking of later down the road of making my own that is accurate and that has more adjustment.

 

[DocB]

Re: Ivey/VGM adjustable bases - anyone used them?

Peter,

I've got a VGM, it works well and I'll put it on a .338 Lapua when I get one. I just set each setting to add 15 MOA (one turret revolution) to the previous one, so as I move out I still have my base setting. Beats twirling the scope knob. I know folks who have them on everything up to .50s, and the VGM has passed DoD toughness tests.

HTH,
DocB

 

[PeterPHWS]

Re: Ivey/VGM adjustable bases - anyone used them?

Thanks for this Dylanss, the accuracy of the system ... is it a situation similar to a scope where you never get a "true" MOA click adjustment ... for instance on my Nightforces I take them to a tunnel range and test the true movement over a maximum height of adjustment as the "tunnel" will allow at 100 yards.
I then divide the "true" distance moved by the scope with the number of "clicks" and then work out what the true MOA click value is for the scope.

They never click an exact 1/4 MOA or 1/8 MOA and as you say ... over the full range of movement this can lead to some significant "variance" ... but once "known" I can then input the true click value to my ballistic software and so far this has worked well.

Usually the "variance" is fairly "consistant" in my N/F's ... meaning that it does'nt graduate by getting worse at certain parts of the movement ... so I can get good repeatability.

Do the Ivey mount's you have work in a similar fashion? From what you have said this seems to be the case.If they give a "consistant" variance which you can work with to have repeatability then that is good enough for me ... it is no different from having to properly calibrate a scope.

What is important is that it is not erratic in certain parts of the movement scale.

This last point is often an issue at the top and bottom end of movements on some scopes ... the click value deteriorates ... sometimes the reticle stops moving but the click mechanism on the turret still turns. I have a US Optics scope which does this but up until the reticle stops moving the increments are "regular" ... but having the turrets still turn and click is what initially threw me off ... and it took a fair bit of testing to work out what the true "movement" range was.

Do your Ivey mounts max out in movement before the click mechanism stops? Do they have a range of movement where they really start to go askew ... like say the last 20 MOA turn ?

Again, if they can give me repeatability even just up to 120 MOA from the total 150 or 160 MOA range I would be happy with that.

The height of the cheek piece I can sort out ... I can swap out the pillars for extra long ones if need be. So long as the position is not one which is unduly uncomfortable.

 

[PeterPHWS]

Re: Ivey/VGM adjustable bases - anyone used them?

Doc, I like the idea of using the VGM base like you do. It saves having to re-do a known distance if you were to calibrate in that manner as a result of barometric and altitude changes.

This way you also get to work with just the "one" true value calibration figure which is the one on your scope. If you have the 10 position model and in my case calibrate each setting with a 10 MOA complete revolution of my scope then there would be 100 MOA available in increments and those increments would match the scope "true click value".

That actually would be a much simpler "set of maths" to work with ...

How does the VGM work in terms of height? Would you fix it straight to the receiver or mount it on an inclined rail to take off the initial bore/scope height loss of movement ?

 

[Dylanss180]

Re: Ivey/VGM adjustable bases - anyone used them?

Peter,

In this case the scope keeps moving while turning the dial all the way to the max. The geometry in all the movement mechanisms is not correct, thus making the adjustment value wrong. I don't know if you have seen any photos of the internals of the system but there are many moving parts. Not just a simple screw like a scope. I forgot to mention that using the scope mount is touchy also. If you go up in adjustment and you go too far. You can't just adjust back to where you want. you have to go down about a full dial revolution or so to get the slop out on the base to get it to move down again. Then you can go back up again. Also there are no clicks for it. The dial is exactly like a micrometer. Then after adjusting the scope base there is a tightening knob on the side to lock it into place. I have forgotten to tighten it a few times making the point of impact shift.

 

[DocB]

Re: Ivey/VGM adjustable bases - anyone used them?

Peter,

1. It's kind of high, but depending on where you position the scope you can use low rings. On my M4, I don't need a cheek piece.

2. They have a couple of different bases available. Mine fits on a picatinny rail, but I know a Remington 700 model is available.

HTH,
DocB

 

[PeterPHWS]

Re: Ivey/VGM adjustable bases - anyone used them?

Many thanks Dylan and Doc for your answers. Looking at this from what I know now I think the VGM might be the best option.

The system of adding 10 MOA per fixed position and those positions being the same as the true scope calibration clicks is easy to work with and I will go with that.

 

[Topstrap]

Re: Ivey/VGM adjustable bases - anyone used them?

I have 3 of them on various guns, I've used them on our XP-100 pistols with great success out to 1000 yards. Am putting one on a Remington 541 22 rimfire and just put the new silver one on my Freedom Arms 44 revolver.

The base unit whether it be the 5 position or the 10 position comes standard with about 110 to 120moa of elevation adjustment but he can easily modify either one to get to about 340moa of adjustment. YES, I did say 340moa of adjustment.

One of my units is the 10 position which bolts directly to the receiver which does make it sit slightly lower and also give you 10 positions to preset. Using them along with fine tuning with your scopes adjustment you can cover nearly any distance you want. The 5 position unit adjustment with a dial indicator works out to be exactly .001 on the indicator is 1moa of adjustment. I forget the exact calculation for the 10 position but it's still easy to check a trajectory chart such as JBM for needed moa adjustment and use the dial indicator and it's usually dead on.

Chris is one of the nicest fellas you'd ever want to meet, he's modified two of mine for specific guns and to correct a slight problem with one of mine with deeper grooves in the mount that allowed the mount to slide over the retaining pin under recoil. He said that is the only one he's ever seen do that and it was on my Freedom Arms 44 revolver. More than likely a sharper and different type of recoil than a rifle. He's said they've put these things on the big rifle calibers with no problems yet. On my bolt action 260 pistols the locking screw never came loose but on the revolver it has backed off. It takes about 2 turns before it will let the slide move but that is something you might get in the habit of checking on a big boomer until you get comfortable with how it works on a big gun.

I'd recommend giving him a call and he'll answer any questions and if you tell him what you have in mind he will probably have a solution for you.

Just got this one mounted today, last year with the old mount it worked great out to 500 yards which will cover a midrange range steel plate match this summer. Should be a fun challenge. The mount is really a piece of art, machine work is superb. This isn't a hard recoiling gun but it seems to put more stress on things than even a really large rifle caliber. I think you'd be very safe with one of these on your new rifle build.

Good Luck

Topstrap

 

[PeterPHWS]

Re: Ivey/VGM adjustable bases - anyone used them?

Thanks Topstrap, I will give Chris a call and talk things through.

 

[mrjimsfc]

Re: Ivey/VGM adjustable bases - anyone used them?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Topstrap</div><div class="ubbcode-body">The base unit whether it be the 5 position or the 10 position comes standard with about 110 to 120moa of elevation adjustment but he can easily modify either one to get to about 340moa of adjustment. YES, I did say 340moa of adjustment.
Topstrap </div></div>

I wonder if the pins could be factory set at 20 MOA intervals? If I'm within 20 MOA I can make the scope adjustment with no problem and use the zero stop feature on my scope to get back to the exact 20 MOA interval associated with any one of the pins. I can easily see how I could use one of the ten position units from 0 to 200 MOA.

 

[KHOOKS]

Re: Ivey/VGM adjustable bases - anyone used them?

I also run one of the VGM one .308 LTR. The VGM is a great product that will let you run any scope no matter the amount of internal elevation. You can set the different positions up in any fashion you can think of. The mount will come with the gage and the math to adjust it for whatever you may need. Chris is a great guy he'll answer any ?'s you have on the units. The mounts are top notch stuff you want be disappointed in the craftsmanship of them.

 

[Topstrap]

Re: Ivey/VGM adjustable bases - anyone used them?

It would be hard to "preset" the pins since you have to find your zero first. It can be whatever distance you like but we usually set the rear pin to that and then using the dial indicator you could set each pin 20moa apart. It's really easy to set each pin though for distances you might find more useful for your particular gun and distances you shoot.

Topstrap

 

[PeterPHWS]

Re: Ivey/VGM adjustable bases - anyone used them?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mrjimsfc</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Topstrap</div><div class="ubbcode-body">The base unit whether it be the 5 position or the 10 position comes standard with about 110 to 120moa of elevation adjustment but he can easily modify either one to get to about 340moa of adjustment. YES, I did say 340moa of adjustment.
Topstrap </div></div>

I wonder if the pins could be factory set at 20 MOA intervals? If I'm within 20 MOA I can make the scope adjustment with no problem and use the zero stop feature on my scope to get back to the exact 20 MOA interval associated with any one of the pins. I can easily see how I could use one of the ten position units from 0 to 200 MOA. </div></div>

I agree. Giving it a little more thought a set up with 20 MOA increments and then using the scope would be ideal. I appreciate though that you need to zero the rifle in before setting these spacings... it is the suggested 200 MOA range on the VGM that I think is a great idea.

A 200 MOA range would enable the mount to be available for use on a much greater variety of calibres. A good point if cost and availability start to prohibit use of the best calibres for this sort of shooting.