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Centra Duplex sight

Posted: Wed Oct 17, 2012 8:19 am
by xnoncents
Does anyone have any experience with the new Centra Duplex? I have been seeing them on several rifles on the ISSF prone World Cup video feeds (thank you hi-def !).
Are they fiddlly, secure, and did you experience a benefit? Thanks for any input.

Posted: Wed Oct 17, 2012 2:29 pm
by Jordan1s
Hi there,

I purchased one of these about 4 months ago and personally, I can recommend them. With the intermediate ring, it is much easier to tell when your sight alignment goes off. I use a 3.8 insert and personally, I would have preferred a slightly smaller ring, although I have heard that you can purchase an extension for the duplex to make the insert appear smaller. The duplex has a very snug fit onto the lenshood of your rearsight and will take some effort to put it on. Functionally, the duplex works great, however, the adjustment knobs on the duplex feel a little loose. The knobs don't have a strong "feedback" when turning them. By feedback, I mean your ability to feel each click you make, like on an anschutz or feinwerkbau rearsight. Also too, the adjustment knobs adjust in the opposite direction of your rearsight. Not a bad thing, but just counter-intuitive. Normally, to make an adjustment to the left, you would turn the knob forward; for the duplex, you would turn the knob towards you. Personally, the duplex did not bring my scores up, but it did make my scores more consistent. Also too, with a more consistent sight alignment, I haven't gotten any "nasty surprises" when checking the shot location. If you need anything more, just let me know!

Posted: Thu Oct 18, 2012 8:24 pm
by nester
How it looks like when you look through the sight?
It's like "additional ring" between the rear diopter hole and front sight ring?

Does this image looks correct?
Gray area - rear dipter disk,
then 1st ring - Centra Duplex,
then 2nd ring - front sight tunnel,
then 3rd ring - front sight insert,
and finally - target
?

Image

Posted: Fri Oct 19, 2012 7:16 am
by efoleyjr
I tried one on my rifle and the duplex ring,4.2mm size, impinged to much on the front sight. It was very close to the outside edge of my 22mm sight and not comfortable to look at. It is a good idea but not sure if it will improve scoring. My sight radius was 33" so that may have effected the spacing and I think it was designed for a 18mm sight. If they had a shorter glare tube it would also help control the size of the 3rd ring. Try before buying or get it where you can return it.
Ed

Posted: Fri Oct 19, 2012 10:01 am
by xnoncents
Thanks jordan1 and efoleyjr for your feed back. I have been digesting what you have said and that created more questions. Why is it necessary to even adjust the duplex left/right up/down wouldn't that be a duplication of the rear sight functions, seems like something is eluding me?
Does the adjustable iris function as a vario insert or is it used for as yet again something else?
I'm guessing that sight radius and personal preference governs which insert diameter is used? So what is the strategy for insert purchasing, some where in the middle work your way out and hope for the best or just buy the lot (avoiding that process was the ultimate reason I sprung for the vario 18mm Anschutz front sight )?
Jordan1, you must be a prodigious shot. Ordinarily wouldn't a increase in consistancy ultimately translate into a better score ? (Than again maybe not. I am a consistently mediocre shooter).
Lastly where did you guys source them from? I cannot find a US source. I have had good luck with Intershoot UK (but like most of purveyors of our 'shiny bits ', pricey ), any one else? Sorry for the pile of questions.

Posted: Fri Oct 19, 2012 9:28 pm
by Jordan1s
Hello,

I will try my best to answer all of your questions.

1. If you don't adjust the duplex ring(via adjustment knobs), your sight picture is going to look something like this. It will be necessary for you to adjust the duplex until all the rings are properly aligned.

Image

2. need clarification on your second question

3. sight radius and personal preference do govern which insert you choose. Personally, 3.8 is slightly too large(although still perfectly adequate), and this is on an air rifle! Personally, I'm not too sure why someone would want an even larger ring. For small bore(and air rifle), I would like mec to create an even smaller ring; Personally, I think either a 3.6 or a 3.4 would be perfect!

4. I would not consider myself a "prodigious shot". Before using the duplex, my scores(air rifle) would be anywhere between 570-582. Since using the duplex, my scores have been between 577-582. My scores didn't necessarily get "better"(I was always capable of shooting 580s) but it did become more consistent.

5. I purchased mine from shootingequipment.de. Michael Klein is willing to answer any of your questions and will get back to you in a timely fashion. He ships your orders quickly and will provide tracking upon request, but be warned! Whenever purchasing any item from over seas, your package can get held in customs for quite some time! Mine was held for about 5 weeks before finally being shipped to me.

edit:

I forgot, you could also try giving Marcus Raab at Centershot Sports a call! I remember calling him about the duplex and he said he could order it for you if you wanted to buy it from someone in the US.

I hope this answered most of your questions! I'm here if you need any more information!

-Jordan

Posted: Sun Oct 21, 2012 7:21 pm
by efoleyjr
xnoncents wrote:Thanks jordan1 and efoleyjr for your feed back. I have been digesting what you have said and that created more questions. Why is it necessary to even adjust the duplex left/right up/down wouldn't that be a duplication of the rear sight functions, seems like something is eluding me?
Does the adjustable iris function as a vario insert or is it used for as yet again something else?
I'm guessing that sight radius and personal preference governs which insert diameter is used? So what is the strategy for insert purchasing, some where in the middle work your way out and hope for the best or just buy the lot (avoiding that process was the ultimate reason I sprung for the vario 18mm Anschutz front sight )?
Jordan1, you must be a prodigious shot. Ordinarily wouldn't a increase in consistancy ultimately translate into a better score ? (Than again maybe not. I am a consistently mediocre shooter).
Lastly where did you guys source them from? I cannot find a US source. I have had good luck with Intershoot UK (but like most of purveyors of our 'shiny bits ', pricey ), any one else? Sorry for the pile of questions.
You can get from Neil Stepp at ISS in Fort Worth,TX
Ed

Posted: Mon Oct 22, 2012 8:03 am
by Sparks
I got one of these a while ago to try out.

Image

Looked great, but had a few problems - for a start, my rearsight got a little complicated:

Image

Okay, so some of that got stripped off, but even after that, it was still a bit... busy:

Image

Now, I have a fairly pronounced cant on the rifle, so that introduced another problem - the duplex is only anchored at the top and I don't know if it's my one alone or the design, but when you cant it, the iris doesn't hang vertically, it moves slightly to one side and makes a mess of your sight picture, so you're fiddling with its adjustment a fair bit to try to get everything aligned. And speaking of which, the sight picture itself gets a bit more complicated as well:

Image

The problem is that the gap between the rear iris ring on the outside and the middle ring of the duplex is just as critical as the centering of the foresight ring in the rear iris, and unless the duplex is perfectly centered in the rear iris - and locked solidly in place - then you get a sight picture like the one above, and if you're mid-match and fixating on the target, you don't notice the small drift offcenter of the duplex in the rear iris.

So for me, the Duplex is now sitting in the pile of Bits I Bought Because They Were A Good Idea At The Time But They Haven't Worked Out So Far But Maybe With A Bit Of Work They Will Later On...

Not that I'm a gadget freak, you understand. I can quit any time I want...

Posted: Tue Oct 23, 2012 4:16 am
by KennyB
Sparks wrote: Now, I have a fairly pronounced cant on the rifle, so that introduced another problem - the duplex is only anchored at the top and I don't know if it's my one alone or the design, but when you cant it, the iris doesn't hang vertically, it moves slightly to one side and makes a mess of your sight picture, so you're fiddling with its adjustment a fair bit to try to get everything aligned.
Sparks, couldn't you just attach the Duplex to the anti-glare tube such that the iris DOES hang vertically when canted?
Just rotate it like you would a leveling bubble.

Alternatively, send it to me 'cos I'd like to try it out...

Regards,
Ken.

Posted: Tue Oct 23, 2012 4:25 am
by Sparks
KennyB wrote:Sparks, couldn't you just attach the Duplex to the anti-glare tube such that the iris DOES hang vertically when canted?
Not so easily because it wouldn't be secured, it would wiggle about from the vibrations of the shot. You could lock-tite it in place I suppose, but that's a bit unadjustable (not to mention hard to set up)...
Alternatively, send it to me 'cos I'd like to try it out...
:D

Posted: Tue Oct 23, 2012 8:49 am
by KennyB
Sparks wrote: Not so easily because it wouldn't be secured, it would wiggle about from the vibrations of the shot
Hmmm, that doesn't sound good.

I guess I'll have to cobble together something similar that's suitably robust then...

K.

Posted: Tue Oct 23, 2012 8:53 am
by Sparks
KennyB wrote:
Sparks wrote: Not so easily because it wouldn't be secured, it would wiggle about from the vibrations of the shot
Hmmm, that doesn't sound good.
I guess I'll have to cobble together something similar that's suitably robust then...

K.
That should be doable, and I know they can be made to work, Peter Hellenbrand was using one in Intershoot and winning with it (second from the left here):

Image

Re: Duplex Insert size

Posted: Tue Dec 20, 2016 2:21 am
by venky
Hello Jordan,

My question is " What size insert for the duplex is right for a 3.6 size front insert? Please help out in this matter. I find a 3.8 duplex insert size is obstructing my front iris.

The bigger front iris, helps in getting a good grouping as small difference in the holding is taken care of.

Venky

Jordan1s wrote:Hello,

I will try my best to answer all of your questions.

1. If you don't adjust the duplex ring(via adjustment knobs), your sight picture is going to look something like this. It will be necessary for you to adjust the duplex until all the rings are properly aligned.

Image

2. need clarification on your second question

3. sight radius and personal preference do govern which insert you choose. Personally, 3.8 is slightly too large(although still perfectly adequate), and this is on an air rifle! Personally, I'm not too sure why someone would want an even larger ring. For small bore(and air rifle), I would like mec to create an even smaller ring; Personally, I think either a 3.6 or a 3.4 would be perfect!

4. I would not consider myself a "prodigious shot". Before using the duplex, my scores(air rifle) would be anywhere between 570-582. Since using the duplex, my scores have been between 577-582. My scores didn't necessarily get "better"(I was always capable of shooting 580s) but it did become more consistent.

5. I purchased mine from shootingequipment.de. Michael Klein is willing to answer any of your questions and will get back to you in a timely fashion. He ships your orders quickly and will provide tracking upon request, but be warned! Whenever purchasing any item from over seas, your package can get held in customs for quite some time! Mine was held for about 5 weeks before finally being shipped to me.

edit:

I forgot, you could also try giving Marcus Raab at Centershot Sports a call! I remember calling him about the duplex and he said he could order it for you if you wanted to buy it from someone in the US.

I hope this answered most of your questions! I'm here if you need any more information!

-Jordan

Re:

Posted: Tue Dec 20, 2016 2:55 am
by Olympic Dreamer
Jordan1s wrote:Hello,

I will try my best to answer all of your questions.

1. If you don't adjust the duplex ring(via adjustment knobs), your sight picture is going to look something like this. It will be necessary for you to adjust the duplex until all the rings are properly aligned.

Image

2. need clarification on your second question

3. sight radius and personal preference do govern which insert you choose. Personally, 3.8 is slightly too large(although still perfectly adequate), and this is on an air rifle! Personally, I'm not too sure why someone would want an even larger ring. For small bore(and air rifle), I would like mec to create an even smaller ring; Personally, I think either a 3.6 or a 3.4 would be perfect!

4. I would not consider myself a "prodigious shot". Before using the duplex, my scores(air rifle) would be anywhere between 570-582. Since using the duplex, my scores have been between 577-582. My scores didn't necessarily get "better"(I was always capable of shooting 580s) but it did become more consistent.

5. I purchased mine from shootingequipment.de. Michael Klein is willing to answer any of your questions and will get back to you in a timely fashion. He ships your orders quickly and will provide tracking upon request, but be warned! Whenever purchasing any item from over seas, your package can get held in customs for quite some time! Mine was held for about 5 weeks before finally being shipped to me.

edit:

I forgot, you could also try giving Marcus Raab at Centershot Sports a call! I remember calling him about the duplex and he said he could order it for you if you wanted to buy it from someone in the US.

I hope this answered most of your questions! I'm here if you need any more information!

-Jordan
If you want a smaller duplex you can consider purchasing a Gehmann centering unit. Since the centering unit hsa an M18 screw thread, you can purchase a variable M18 front sight and attach it to the Gehmann.

http://www.gehmann.com/english/products ... tegorie=24

Re: Centra Duplex sight

Posted: Tue Dec 20, 2016 10:05 am
by Peter_Scant
I've been using one for a few years and have found it increased consistency. Rather than making the foresight more centred in the rear sight, I found it improved head position behind the rear sight as you can see any change in eye position behind the rear sight including eye relief. I found it worked better than the mirror.

Re: Centra Duplex sight

Posted: Wed Dec 21, 2016 3:24 pm
by Olympic Dreamer
Has anyone bought a Duplex Vario? http://shop.mec-shot.com/duplex-vario.html How does it look? Any reviews?

Re: Centra Duplex sight

Posted: Sun Nov 05, 2017 7:58 am
by Durkee Atwood
I have found that different ranges can present many visual challenges that can influence rear iris centring about the foresight tube. These may include dark or unlit timber at ground level and/or encroaching supporting verticals or baffles. This makes it difficult to trust carefully adjusted head/eye position established by the adjustable cheekpiece. The result of the visual distrust is to push the head in the direction that appears to be lacking concentricity. Unfortunately, this will throw the resulting shot in that direction. The answer is, of course, to trust muscle memory and ignore the perceived visual interruption. The problem with this is that your original setup might have been adjusted to suit the ‘cutoffs’ of the range you regularly shoot on and when you shoot on other ranges your groups become much bigger or horizontally or vertically displaced. This is particularly noticeable with 50M prone and where the top sighters are centred but the bottom groups are higher. This may be because visual cutoff is greater at the bottom of the rear iris/foresight relief than the top. This might cause you to involuntarily lift the head off the cheekpiece to gain perceived edge distance parity.

The Centra Duplex can help to provide a further reference to concentricity that may confirm muscle memory and how your head is naturally supported by the cheekpiece for consistent grouping regardless of cutoff and incorrect visual perceptions. Group consistency is a basic requirement and this should not be influenced by differences in sight picture caused by image cutoff or variable light conditions.

The centring of the rear iris and foresight tube can have a greater affect on group shift than the foresight aperture and the target. The reason that all shots can not pass through the same hole is because of foresight aperture shake. The reason for groups moving into the 9 ring is rearsight misalignment. This provided there is a completely relaxed hold, no flinches and trigger control and follow-through is ultra smooth and maintained that way throughout the session.

Re: Centra Duplex sight

Posted: Tue Nov 07, 2017 10:12 pm
by MarkTrew
There have been several pictures showing an offcenter sight picture. I think someone suggested a twisted installation. That is one solution. Another solution is a colliminator shade from Centra.

The practical limit is about a 22mm front sight. For those experiencing too tight of a ring, Centra makes extensions to lengthen the distance between the rear iris and the duplex unit. I think the lack of the extension was the issue Ed Foley was experiencing?

All that being said, I use one. I like it, but one needs to recognize that one WILL need to experiment to achieve their optimum results, IMHO

Thanks

MarkTrew

Send an email for better details mrktrew@verizon.net

Re: Centra Duplex sight

Posted: Sun Jul 05, 2020 12:09 pm
by rlporter507
I just received my lens hood an a assortment of iris from https://oberleenterprises.com/shop/
not having the adjustable body, i have the "not center problem". I believe the cause of this is the bore through the sight body is not parallel to the rifle bore, we dont notice it because its so short, but when you put an adjustable iris, and then the lens hood out the front, making it quite long, with a reference mark, the duplex iris, it becomes quite apparent. the reason the duplex adjustable body turns the wrong direction is because its on the front of the rear sight, its the same as adjusting the front globe, directions are reversed.

Re: Centra Duplex sight

Posted: Sun Jul 19, 2020 4:57 pm
by MarkTrew
Responding to the "I have the "not center problem". , I suggest it will not automatically align itself. This is just like sighting in a rifle with a new set of sights, one must tinker abit. If it still doesn't align perfectly then a colimator might be indicated.

Earlier in the thread someone noted the Duplex came loose. I use one on my 6BR 300m Rifles and have never had an issue. One must use the correct lenshood. Cobbling something together is not necessary.

Also, there are provisions for locking the adjustments, all built into the Duplex. It should not move during a string. It does not seem to change positions for me. I take my sights off to pack the rifle away and install them later for the next session.

I know better scores can be achieved with this device, I have shot some nice prone scores with them on a couple rifles. The upper positions have failed for many reasons.

Should you care to discuss in detail feel free to email me at MrkTrew@verizon.net

Mark Trew