Red Dot Mounting Preference + Cowitness

[Ducman69]

I purchased a Bushnell TRS-25 Red Dot, and first mounted it towards the front of the factory rail about centered over the magazine of my PLR-16.

This seems to work fine, but renders the rear iron sight useless. The TRS-25 has a little deal on the bottom right corner inside the tube that partially blocks the view and prevents cowitness. Also, with the TRS pushed up too close to the iron, its a pain getting the big rubber lens protector on and off.

I found however, that if I mount the red dot in place of the rear iron sight at the very back of the rail, and relocate the rear iron to the front of the rail, the irons can be very easily seen through the glass. This would also seem to make the gun less nose heavy.

Can someone explain why this is a good or stupid idea? Definitely doesn't seem popular for some reason.

This is the sight picture, sorry the dot was turned off:

PS: As a homebody, my TRS-25 is not likely to get damaged or run out of battery, so should I even bother with having backup irons and just pull em off? Thoughts?

 

[shanzlik]

The further apart you mount the iron sights, the more easy it is to be accurate with them due to the longer sight radius (it reduces the effect of misalignment errors). That's why you don't see them like that. It can work, it's just unusual and not optimal for using the irons.

http://www.shootingillustrated.com/index.php/15546/the-power-of-one/

Scroll down to the "Sight Radius Is Your Friend" section for more details on the effects of a longer sight radius.

 

[Double Naught Spy]

I would move the iron sight as far back as is functionally possible so that you aren't dealing with such a short sight radius for the iron sights. The shorter the sight radius, the more difficultly people have in maintaining proper sight alignment. For example, with a 4" sight radius, if you hold is off by 1/64", the same 1/64" hold would produce only half the down range error if the sight radius was 8".

Of course, given your gun type and the likely distances you may be shooting, this sort of error may not be all that consesquential to you, but I would still want to err on the side of being easier to be a more ergonomic-friendly shooter than not.

Don't pull off the iron sights. They aren't doing you any harm. Some day, you are likely to have the battery turn out to be dead and quite likely it will be when you are at the range and where no replacements are available and your gun will be sightless (hence you probably should not be shooting it if you can't aim it properly) and that part of your range trip will be ruined.

 

[Ducman69]

Alrighty, put it back about as far as I can before it starts becoming obscured by the "hump" in the RD optic:

Thanks for letting me double-check, as I'm always worried when it seems I'm the only one to do something different/backwards heh.

 

[Double Naught Spy]

That looks like it will work just fine.