# Thread: Can someone help me with sight height?

1. ## Can someone help me with sight height?

Hey folks... I'm usually pretty good with gun stuff etc. but I'm coming up short with trying to get a sight height on my Ruger M77 MKII. I've got a stainless rifle I'm trying to put after market sights on and there seems to be lots of options as to height etc. So.... How do you best measure front post height needed?

Mountaintrekker

2. I can give you a little formula if you want to try to follow along. First measure the barrel diameter at the front and rear sight locations.

Now take half these measurements and the rear we'll call 'A', the front we'll call 'C'.

Example:
Rear diameter 1.00" divide by2=.500" = A
Front diameter .700" divide by 2 =.350" =C

Start with a rear sight height and we'll call this 'B' find this in the catalog for where you buy the signt if ajustable use the mid point of sight height.

Let's say 'B' is .400"

Now to find the needed front sight height, which we'll call 'D' the formula is: (A+B) - C = D or .500" + .400" = .900" - .350" = .550"

Now to find the rear height when the front is known we use:
(C+D) - A = B or .350" + .550" - .500" = .400"

We can do it Algebraically if you'd like.

3. Murphy,
That is great! Thanks! One other question though... this formula is for using the barrel as the point of reference for height, correct? What if I have the rear sight up on the reciever? Thus I would have a front on the barrel and a rear up on the reciever... any formula for that?

Thanks for the info!

Mountaintrekker

4. Originally Posted by Mountaintrekker
Murphy,
That is great! Thanks! One other question though... this formula is for using the barrel as the point of reference for height, correct? What if I have the rear sight up on the reciever? Thus I would have a front on the barrel and a rear up on the reciever... any formula for that?

Thanks for the info!

Mountaintrekker
The companies that sell receiver sights and backup sights that mount on scope bases usually give the info about front sight needed or to use with their own sights. If you put a set of scope bases on the rifle you can straight edge some rifles with a yard stick to get front height. Rugers have two different rings because of front and rear of receiver height is different so put the rings on an put a broom stick through for front height then subtract some from front and rear if mounting a sight on the rear ring base, for the front sight height. Failing this you can ask for measurements of front sight from others guns of same type/brand etc.

5. ## Brownell's

There's a technical article and a sight height calculator on the web at Brownell's dot com. Here's the link: http://www.brownells.com/aspx/NS/GunTech/sight.aspx.

Good luck.

6. Thanks folks!

Regards,

Mountaintrekker

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