How far is a click? 1

[swertel]

I need to develop a mount for an ACOG Scope that has an adjustment of 3 clicks per inch at 100 yds. So how far is a click is terms of units that I can relate to my mount? Basically, I need to know if the mount I'm developing can be level or if I need to design in an angle in order for the projectile's trajectory to match the existing peep sights.

I'm asking here because I could easily ask a coworker and look stupid since I don't know something that is common sense in this industry, or I could ask here and look smart.

--Scott

For some pleasure reading, try FAQ731-376

 

[Carburize]

Typically "a click" is the distance an adjuster screw moves between detent devices. A sight might, for example, have a adjuster screw with semi-circular notches cut into the side of the screw head into which a spring loaded pin locates. The distance between the notches is "one click".
You can obviously make "a click" any dimension you want depending on the pitch of the thread and the distance between the detent locations.

 

[swertel]

That's what I was afraid of. Thanks, Carburize. Time to email the scope maker.

--Scott

For some pleasure reading, try FAQ731-376

 

[arto]

3 clicks per inch @ 100 yards {~1/3 minute-of-angle} sounds pretty coarse.
my $35 simmon 22 scope is 1/4MOA per click.

 

[tsboxman]

Many standard rifle scopes have 1/4 MOA adjustment knobs while some target scopes offer 1/8 MOA (Minute Of Angle which equates to 1/4" for th 1/4MOA adjustment at 100 yards, 1/2" at 200 yards, 3/4" at 300 yards and so on.) In your case, as Arto mentioned, would be roughly 1/3 of an inch at 100 yards. Rough maybe, but if I am not mistaken the ACOG is set up for the .223 AR-15/M-4 systems where the range is not excessive. Magnification is usually lower so fine adjustments may not be necessary. The ACOG is a combat scope compared to that of a sniper scope.

What type of mount is the scope for? Weapon?

 

[IRstuff]

Back to one of your original questions:

My understanding is that the scopes are always designed to be level.

To some degree, this makes sense, since otherwise, you'd wind up designing for a particular weapon, since each weapon would have a relatively unique distance from sight to mount.

TTFN

 

[tsboxman]

True.
Again it goes back to if it is a specific weapons mount or if it is a general rail mount. If it is a mount, say for an AR-15 handle mount, the top rail should be level while the bottom is going to be tapered. The handle angles downwards. If it is a rail mount for a flat top it will probably be level. The scope should be able to adjust to compensate for elevation - there may be an adjustment on the front for that purpose. (I may be thinking of another combat scope so that could be incorrect, although the reticle elevation adjustment should compensate)
Some scopes do angle downwards depending, again on the setup. You shoot upwards to have the bullet fall on a specific zero at a designated distance. I do not know if that applies to the ACOG.

You may just want to get clarification from someone there to be sure... Sometimes its better to look "stupid" then end up being "stupid". (Although its a hard lump to swallow sometimes, you should have the internal resources to ensure accuracy no matter how "simple" a problem seems to be.)

 

[swertel]

Already went the look stupid route. Basically, our answer was to create some rapid prototypes of my concepts and send them to the customer. They will test them out on their units and give me feedback on the preferred concept and any user-friendly changes.

The history behind the question is because we have several mounts (Picatinney rails) added to our weapon system to fit customer desired optics such as the ACOG and a AN/PEQ-2. Since our projectile doesn't follow a straight-line trajectory like the laser on the PEQ, we had to create the rail with a taper that matched the trajectory at a specific distance. It is up to the gunner to compensate the laser spot with the actual trajectory at any other distance.

Considering that the ACOG also gives a straight-line target through the retical, it will also have to be sighted in at a specific distance. Of course, this may all be a mute point because we learned from the customer that the gunners have the ACOGs for another unit. In the field, they will quickly take the ACOG off that, place it on ours, fire, and put it back on the other system. No time to sight the ACOG in to our system so it is up to the gunner to mentally make any corrections.

--Scott

For some pleasure reading, try FAQ731-376

 

[tsboxman]

Glad you have an answer anyway. Sorry you had to go "stupid" route.

Sounds like an interesting field. I have been trying to brainstorm ideas on the rail systems (One of my ideas was already in use - figures) but I do not have the interaction with the industry. Been toying with it some on my free time just for something to do.

Anyway, hope your system works out.