– Eratac VS Ivey –
Adjustable Scope Mounts
Eratac VS Ivey?
A popular discussion with ELR shooters. We took a few months with both systems to decide what may work so here’s our take on these two adjustable systems. This long term review should provide you with sufficient info to make up your mind. IF you have any questions about the eratac or the Ivey mount, feel free to drop us an email.
Rifle scope mounts are decisively important – they make you or break you. Adjustable scope mounts like the Eractac or the Ivey Mount take it a step further. Adjustable scope mounts like these enable us to change our base zero by building in further adjustment in the scope base on the fly. In essence we are increasing the angle of the rear part of the base, the reticle moves further down on your target so you will have to point the barrel up higher therefore adding more elevation. For those of you that have been in long range shooting for sometime, we all remember the discussions around the amount of built in angle in MOA/Mils required in our base and the headaches some would have in getting their setup right. Those days are somewhat gone.
However do not underestimate the usefulness of simply bore sighting your rifle and scope. It will already show you whether you will be able to zero your setup way before you head to the range as well as giving you a very good idea of how much scope travel you are going to be left with after zeroing your rifle. If you want to learn more about how to setup your scope head to this article
What do we need Adjustable Scope Mounts for?
Many shooters would have 20,30 or even 40MOA built into their base to enable them to reach the distance they were after. In a nutshell, scopes offer limited amount of travel. This has improved over the years somewhat, however 70-120MOA tends to be where most scopes are. If your scope turrets are mechanically centered as they ideally should be, you would be left with a little over half that elevation travel by the time you zero your rifle. That means you may be left with 35-60MOA of elevation with most scopes today. The traditional bases with built-in MOA would help you offset some of this. Let’s say you had 50MOA left in your scope after zeroing and you add a 20 MOA base, you are now armed with 70MOA of vertical travel. Sufficient? Depends what you’re after and what rifle / cartridge you’re shooting. If you have too much angled built into the base, you may not be able to zero your rifle at 100m/yds.
Not a big deal but good to be aware of it. We have one particular 300NM rifle that is zeroed at 600m. Our near 100m zero is about 10.5MOA high. We then simply input this offset in kestrel which will deduct that amount from the dope it will give us. Out to 600m, it will give us a negative value (hold under).
Enter the adjustable Eratac and Ivey scope mounts.
Adjustable scope mounts enable you to go from 0 MOA to their maximum amount of travel in just a matter of seconds. The Eratac adjustable mount enables you to go from 0-70MOA by turning a knurled wheel which rotates this eight-sided irregular hexagon which in its every movement, adds 10 MOA to your base. Pretty cool isn’t it? Indeed it is and the Eratac works very well. It’s made for various scope tube dimensions including the popular 30mm tube and 34mm tubes. Seen below, we mounted a Vortex razor genii 4.5-27×56 to boost the 78MOA available on this scope. After we zeroed our rifle, we were left with about 50MOA. (sufficient to shoot a 300NM to 2kms in most weather conditions) however if we wanted to shoot even further, we could crank on an additional 70MOA. Remember, past its supersonic range, the drop of the bullet will increase FAST and will eat up your vertical travel easily.
Above: Eratac 34mm. Notice the knurled wheel which is used to adjust the elevation settings with. In this configuration, I had 78MOA on the vortex and 70MOA on the Eratac for a total of 148MOA of vertical travel plus the hold over possibility offered by a reticle such as the EBR7C shown below.
Adjusting the Eratac – video clip
It’s simple, you need to loosen the front and rear screws, takes about 3 turns with a screw driver and then it enables you to turn the knurled wheel. Once you set the amount you are after, simply retighten those front and rear screws again and you’re ready to rock those far away targets. The idea here however perhaps is not that you will be adjusting this in between shots during a match, but rather it enables you to get the setup right where you want it to.
Otherwise adjust it to 70MOA to enable you to reach way out there essentially supplementing your scope with a further 70MOA. To use the example I’ve already mentioned, let’s say I was left with 50MOA after zeroing my rifle at 100m/yds. You may now adjust your Eratac adjustable mount to 50MOA and dial the difference on your scope turret to continue where your scope previously came short. In essence this means you now have 100MOA of available travel.
Above, Ivey adjustable mount (0-200MOA) sporting a March 5-40×56. Beneath the Eratac Adjustable Mount (0-70MOA)
I have setup the Eratac against a tall target at 50m to check that it is repeatable and consistent being very careful not to move my setup. I mounted it onto a rail and mounted the rail in a vice. The base is indeed repeatable and the reticle moved up and down ten times coming back down to my original zero.
I also tried dialing in 70 MOA on my scope turrets to see the reticle move downwards on the tall target to a specific point. Then I had someone mark that point for me on the tall target. I know that point is now 70MOA of travel. At this distance you can do it very accurately on 20x mag. I then adjusted the scope turret back to zero so that the reticle would climb back up to my starting point. I then adjusted the Eratac to 70MOA so that I would see the reticle climb down the tall target test to the same point where it had been when I adjusted my scope turrets. That’s a confidence builder.
How much does eratac weigh?
The Eratac adjustable scope mount is fairly light, weighing in at 430grams for the version I have, 34mm tube 30mm height. On top of the rings, you will find 4 additional screws that enable you to mount other sights for close range work.
(picture source: https://twobirdsflyingpub.wordpress.com/2014/01/29/shot-sow-2014recknagel/)
Update Eratac solid return to zero.
Eratac in MOA mounted on this solid RPA Range Master in 300NormaMag & 338Lapua configuration. Made in UK.
While in Italy this week, I decided to run a quick test using the Eratac, I had just removed it from my 300Norma Mag to mount the March Genesis and give the 300 Norma a go at 2000m with this setup. I thought it was a good opportunity to see how well the mount holds up after removing it and placing it back on the rifle and tightening it up to 80 inch/lbs on the picatinny rail. I drew a target up with a vertical line, a horizontal line crossing it and a small circle 1/2MOA above the crosshair. I placed one round from 92m distance which hit the vertical perfectly 1/4 inch below the horizontal line. below you can see the one round that clipped just beneath the horizontal cross hair at 92m. The gun was zeroed at 100m. Perfect confidence in the system. Scope is March 5-40×56 with FMA-MT MOA reticle with 1 MOA hash marks Xmas tree like reticle. With the 300 Norma Mag, you can basically hold and shoot any steel plate target easily to 1000m.
Can the Eratac mount be improved?
Maybe yes, I would upgrade two things if possible to this excellent and dependable scope mount.
First, have 100MOA instead of 70MOA if it were mechanically possible to have that. This would enable most ELR scopes with 100MOA+ of adjustment to have over 200MOA of elevation and a tad more without needing to have an offset Zero. Learn more about setting up your rifle with a Zero offset and inputting it in kestrel.
Secondly, If mechanically possible, I would do away with the need to have a tool to loosen the screws that enable you to turn the rear dial and instead have some sort of quick tightening system as we see of QD scope mounts. The smart engineers at Eratac may eventually find a solution for this. Other than that, for the price and quality, it’s an unbeatable option that I consider having on any ultra long range rifle simply because it allows me to maximize the scope I have without having to work out off offsets or picatinny rails with built in angles unless you’re shooting really far away targets. The lighter weight of the Eratac meant I could use it on more rifle systems even though it is more specialised than a ‘normal’ scope mount but with 3 ELR rigs in the gun cabinet, the ELR bug is not going away anytime soon so the Eratac is staying.
Ivey Mount – An Eratac on steroids? See specs
What would be better than the Eratac? If you want to reach out further and do not want to carry any tools, the Ivey might just fill your ticket if you want a turret adjustable scope mount. It also weighs more than twice the Eratac. (907grams vs 430grams for the eratac) and comes at about twice the cost here in Europe.
Ivey Scope mount first Impressions
The first impressions unboxing the Ivey, it’s chunky, like a military scope. It feels solid. There is more meat around the rings and the rings are wider. Each ring is secured with 6 screws rather than 4 although I’m pretty sure no scope is moving in any of these setups. Harry from Solid Solution Design in the Netherlands has tried it on his DTA 416Barrett 40inch barrel rifle and he reports no issues. Like me, Harry travels a few hundred miles each way to get shooting these ELR rigs so if it didn’t work for him, it wouldn’t sit there. I wasn’t sure which one would work for me so I got them both at different time intervals.
Below you may see the two mounts as you would sitting behind your rifle. They are almost of the same height, about the height of a 375cheytac case actually shown there. I mounted a March 5-40×56 FFP scope with an FMA-MT reticle illuminated. (review coming) This is basically the same reticle available in the Genesis ELR scope. I am a March scope fan so I wanted to use this FFP scope on my 33XC build. This scope model has 78MOA of internal travel which is why I coupled it to the Ivey. This model was fitted with the FMA-MT on request and so far, i’m very happy about it. It’s a very fine reticle, reminds me of the NPR1 reticle on the Nightforce BR scopes series. For fine holds at ELR distances, it should be fair game.
There is a built in bubble level in the Ivey scope mount too which is always nice to see. So when do you need an Ivey Scope mount with upto 200MOA (60Mils)? Well definitely it’s for ELR shooting. Kestrel numbers indicate that shooting the new 33XC to 2 miles will require a pretty push that would make my math teacher envious. We’re looking at about 190-210MOA depending on the atmospherics. That means we can virtually dial up to 180MOA on the ivey and add 10-20MOA on the scope. The Ivey side turret for elevation is marked in 5 MOA increments with 2.5MOA hashmarks in between.
Ivey Clicks: You can feel that you are going past each 2.5MOA increment. It doesn’t click like a scope turret but you feel a nudge past each hashmark and there is no discernable play. Every turn forward will move the scope 50MOA up. For our 2 mile shot, we need 3 turns plus 30MOA. Ivey suggests that you go past your intended adjustment and come back when dialing in your setting. Then tighten the locking nut again.
Here is a quick video to help you visualize the clicks. I cranked on 70MOA to compare to dialing in on the Eratac.
NEXT – Ivey Mount TEST return to Zero.
I did a few extensive tests with the Ivey Adjustable Mount to check the return to zero capability. I had a dedicated platform built with a picatinny rail weighing 10lbs just to make sure we get the right platform to test the Ivey ELR mount without any issue of movement. I lined it up on a 50m target and dialed up and down in 50 MOA increments to check if it were true. This stable base coupled with the 40x magnification of the March 5-40×56 meant we could see the aim point extremely well without issue and easy to check if the reticle is actually returning to the same point of aim. Over the entire range of 200MOA dialed, I found mine was 1.5MOA more than advertised but it was consistently that way. The only reason why I eventually parted away with mine was that I did not want to keep track of two elevation dials on two different planes during a competition environment. I think it will work great for those that want to do ELR in their own time or who have enough time to practice with two elevation dials on two different planes, the one of your scope turret and the one on the side for the Ivey. Remember as well that you will need a good 18MOA+ of windage at ELR distances say past 2000m+ in strong winds which none of these systems will give you so you will have to rely on your scope windage plus the reticle. Most scopes have 10-15MOA per half turn on the windage so you will start to stretch it.
What does a target look like at Extreme long range Distance?
Here is a target at 3527 Meters. Consider most ELR rounds will have about 18MOA of wind in 10mph at this distance. The MOA reticle below on the March Genesis FMA TR1 reticle gives you an idea of what that looks like at 2Miles plus on 40x mag.
Below is a one Mile object on 20x. a 300NM will need about 8-9MOA of wind in 10Mph at this distance.
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