Aimpoint T-1 POI shift?? (Green Eye Tactical Bans T1 RDS)

[Green Eye Tactical]

I think another consideration is to decide once and for all if you want to co-witness with iron sights and STICK TO IT.

Here's my reasoning:

I employee the Meprolight M21 as my CQB optic. The triangle reticle to me is optimum for both placing the "whole" reticle on close-up targets or using just the tip for objects further away.

When I employ the optic with no cowitness, the reticle actually sits slightly above the front sight post in the most comfortable position. When I use a co-witness, the reticle actually appears to be touching the front sight post when lined up perfectly. Common sense says that this is introducing some error into the target acquisition versus zero (albeit maybe a small one).

I've never compared the difference in POA vs. POI when using the Meprolight with or without irons co-witness, but I'm guessing there must be some. There would almost have to be.

Again, I would agree with you. That is- IF co-witnessing is reliably possible in your operational parameters. An example is low light or NVG use. Another example is usage with protective masks, where getting your line of sight low enough to align with a lower 1/3 or even absolute co-witness may not be possible without running your optic on a riser to achieve a higher height over bore. Another consideration with a lower 1/3rd co-witness is that some red dot optics (including MRDS's) exhibit a higher degree of aiming dot movement in the lower 1/3rd of the window.

I will say, that through observed performance- that referenceing the dot to the front sight can reduce this error, however it does not completely eliminate it with some optics. However- I have found that most optics do not require it. A really good example is the MRO. It has a really odd movement pattern and appears to have horrible performance if you only read the test results. However, in practical application- I have not observed any students have any issues with major POI shift between seperate groups as I have seen with others. The test data is just that- data. It may or may not be valid for your usage.

So, not saying that the method you propose is right or wrong. The better question to ask is- Is it neccessary? A valid method might be to first determine if the control proposed is neccessary before implementing it.

[Canonshooter]

I always thought it was just common sense to center the dot in the optic before firing.

Yes, but for as long as I can remember one of the claimed benefits of a RDS is not having to do so - all part of the manufacturers "no parallax" claim. While this may be OK for close targets, not centering the dot can obviously cause problems when greater precision is required. Until I read Eric's study, I did not realize how much error there can.

This also explains (to me at least) why in the photo threads there seems to be a growing number RDS/fixed-front-sight set ups, using a folding rear. Using the front sight post as a reference makes a lot of sense now that all of this has been discussed.

Which leads my feeble brain to this conclusion: if referencing the front sight is necessary for greatest RDS accuracy, why not just use irons? Yes, I've heard all of the arguments for the benefits of a RDS (some of which are obviously valid), but I'm left feeling that they are not the sighting panacea some would lead us to believe.

My hat is off to Eric for his efforts and my thanks to him for educating this RDS half-wit.

[Doc Safari]

Which leads my feeble brain to this conclusion: if referencing the front sight is necessary for greatest RDS accuracy, why not just use irons? Yes, I've heard all of the arguments for the benefits of a RDS (some of which are obviously valid), but I'm left feeling that they are not the sighting panacea some would lead us to believe.

That thought has crossed my mind on many occasions. I even keep a Colt LE6920 with the carry handle on it for just this reason. I want to stay in practice with irons no matter what optics I favor elsewhere.

In my experience, a good red dot with a generous window is still faster than an iron peep sight. I used to shoot competition so I kind of have some relevant trigger time. Iron peep sights are great for slow precision aiming. RDS reticles are great for "put the dot on target and fire". Presumably the average person is savvy enough not to expect to use an RDS to engage targets at anything beyond 300 yards--and personally I think ranges under 50-75 yards are the more realistic useful distances for an RDS. Anything beyond that and a 1-4 LPV might be a better choice.

I know people disagree, and I'm sure people do use RDS's effectively beyond 300 yards, but that's why it's an internet forum and there may not be a 100% perfect answer that applies to all people.

[montrala]

My experience with Aimpoint (CompM3, CompM4S, T1, H2) was that dot basically stays put in some 80% of FOV, then starts to move a bit and then moves a lot in last like 10% (close to the edge). In Eotech dot moved for me constantly in FOV with increased angle of sight. I did this testing for myself in following way: I fixed rifle with RDS in special "zeroing" fixture (common on ranges that hunters use around here) and pointed it at IDPA target placed 100m away in way that with perfect eye placement dot was i middle of A-zone. then I was moving my head around to see what happens. In case of Eotech (I believe it was 553 and ad this time it was declared to have parallax fixed ad 60m) maximum dot movement was about edge to edge of target. I did not test any other Eotech that way. With Aimpoints at extreme angles maximum movement was about C-zone size).

What practical knowledge I got from this? That at close range it absolutely does not matter how I look trough Aimpoint, as long as I see the dot, so I can shoot as fast as dot goes on target, without trying to center dot inside sight. And on middle to longer range it is good to have a better head placement, especially when I need to put down mini poppers at 200m on timer.

TL;DR I just do not get the drama.

[RHINOWSO]

So this means you need to know your equipment.

Check.

[montrala]

So this means you need to know your equipment.

Check.

There is that.