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fr8

Please help: I'm going to the range tomorrow to sight-in my FR8. Which of the three sights on the rear sight wheel do I use to sight-in at 100yds.?
What are the three sights used for?

I copied and pasted the following from Surplusrifle.com which I believe was then continued on Tennessee gun parts which I can no longer find.
Anyway, the credit for this post is to Kevin of one of the previous websites.

FR8 sight adjustment Repost (Credits to Kevin)


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sgthurley
Post subject: FR8 sight adjustment Repost (Credits to Kevin)
Posted: Sat Apr 22, 2006 9:06 pm
Benefactor

Joined: Sun Apr 16, 2006 7:39 am
Posts: 6087
Location: Oswego, Southeast Kansas
Age: 61
The sights are similar to the cetme rear sight. the v notch is 100m and the others are 200-400, you can figure it out with the higher holes being greater range. They are easy to zero. My advice is use the 200m peep at 25 meters to zero. This will get you zeroed for the other setttings at the 100m increments. The 200m meter setting should hit the bullseye at 25 m and 200m (according to manuals and many people's accounts) I cant do too well with the v notch rear sight, i allways use the peep sights. Also dont forget to loosen the set screw on the front of the tripple frame! I made my own front sight adjustment tool with a dremel and old screwdriver with a broken off tip. Cetme front sight tools work for the FR-8 as well

I copied and pasted this from another forum that im a member of:

The CETME/FR-8 rifle is adjusted for both windage, and elevation from the front sight post. It is also adjustable for bullet drop compensation at 100, 200, 300, and 400 meters from the rear sight paddle wheel, but we want to concentrate on the front sight post. The front sight post is housed inside of the triple front frame sight just under the top hood of the triple frame. On the front of the triple frame towards the muzzle brake will be a small set screw that locks the front sight post down. This needs to be loosened before trying to turn the front sight post. WARNING, if you do not loosen the set screw in front, you will most likely strip the threads on the front sight post. Now, to make adjustments to your windage, and elevation, you need to understand how the sight works. The front sight post is not dead center of its base, it is offset 0.6 mm. from dead center of the sight post base, and this is how the windage it set. Elevation is set by either raising the front sight post by unscrewing it counterclockwise, or by screwing the front sight post into the frame clockwise lowering the post. It is important to shoot for elevation first, and get the elevation correct before starting to mess with windage on this rifle. On top of the triple frame front sight is a hole. This hole allows you to insert a front sight adjustment key through it to adjust the front sight post. On two sides of the front sight post, you will see 2 holes on opposite sides of the front sight post base. These 2 holes are for the 2 spikes on the front sight tool to rest in, and allow the tool to turn the front sight post. Once you have elevation set, you can then concentrate on windage (left or right). Setting windage is done by offseting the front sight post left or right from dead center. It will offset your elevation up or down just slightly when setting windage, but not more than 1/2 inch up or down. The following picture should explain how windage is set with the front sight post




cetme/FR-8 front site specifics

-elevation - for every 360 degree turn on the front sight post, it will move the point of impact 2.15 - 2.3 inches at 100 yards. For every 180 degrees turn, it will move the p.o.i. 1.075 - 1.15 at 100 yards

-windage - for a full swing left to right, or right to left (180 degrees from either 9 o' clock to 3 o' clock, or from 3 o' clock to 9 o' clock) it will move the round 7 inches at 100 yards. For a half swing (90 degrees from 12 o' clock to 9 o' clock - or from 12 o' clock to 3 o' clock - or from 6 o' clock to 9 o' clock - or from 6 o' clock to 3 o' clock) it will move the round 3.5 inches at 100 yards.

-always adjust elevation first! Once elevation is right, then adjust for windage. Note, if your sights are really far off, it can raise or lower your poi by as much as 1/2" at 100 yards.
-the thread size on the front sight post is
tpi 72.5
tpmm 2.85
1 rotation = .35mm-.375mm/.0138"-.0148"


Here's how this works First I counted the threads on the post, and measured the total length of threads with a nice set of calipers, then divided the length by the number of threads to get the distance per thread. Then used geometry, Tangent = Opposite/Adjacent (for a triangle)
we know that Adjacent is distance from rear sight to front sight, which is 23". Then we know Opposite is distance per thread.
So the Tangent is .0006 degrees. If we multiply that by 3600inches (100yards), we get the ANSWER!

There is an even simpler way to determine the length of one minute of angle (M.O.A.). I got this out of Crossman's Book of the Springfield, he did the math I just use the easy formula! Multiply the rifle's sight radius by .000291. This will give you the amount of sight adjustment in inches (on the rifle), to move the point of impact 1 moa at the target.

For example if the sight radius is 26" then (26) x (.000291)=.0075
That means every .0075" movement of the sights (front or rear) equals 1 minute of angle at the target.

This information was provided by "capman"
If you need to make the point of impact go down, you would move the front sight post counterclockwise, or up.
if you need the groups point of impact to go up, move the front sight post clockwise, or down.
if you need the point of impact to move left, you would turn the post until it moves to the right of center.
if you need the point of impact to move right, you would turn the post until it moves to the left of center.
if center of your 3 shots is 3 1/4 inches high, and 2 inches right to the center of the bullseye at 100 meters, raise your front sight post 1 full 360 degrees turn, plus another 180 degrees turn - 540 degrees total - then once elevation is right, you have to adjust for windage. Your shots are 2 inches to the right - assuming that your post is at the 12 o clock position, move the post to the 1 o clock position. If your post is in the 6 o clock position, move it to the 5 o clock position.


 
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