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20 MIN SCOPE RAIL

Posted: Fri Aug 01, 2008 9:51 am
by Paul Janzso
Does a 17 min scope rail equate to approx. 0.3 degres or to be precise 0.283 degres ?

I just need to make up some drop charts and the Barnard tapered rail's are 17 min.

Cheers
PJ

Posted: Fri Aug 01, 2008 10:30 am
by Woody_rod
pest bird,

Degrees, minutes and seconds just like time, although there are 360 degrees of course. 17 minutes is almost 1/3 degree (60 minutes to degree). 0.283(r) degrees is correct.

Posted: Fri Aug 01, 2008 4:57 pm
by Paul Janzso
Thanks Rod .

PJ

Posted: Sat Aug 02, 2008 3:44 pm
by Robert Chombart
pest bird wrote:Thanks Rod .

PJ


Hi,

On a standard lenght action, say 190-200mm, 1 minute rail slope represent some 0,05 mm slope; well within machining tolerances. In other words, your rail can either be 16 o 18 minutes slope and still be in the said tolerances.

There is so many other variables that you better take an average in your calculations and fix the rest at the range with your preferred ammunition....

Robert Chombart

Posted: Sun Aug 03, 2008 11:11 am
by Woody_rod
Pest bird,

Robert makes a good point. I think put simply, you might want to check that the rail is actually 17 minutes and not 15 or 21, to make your calculations more accurate??

Re: 20 MIN SCOPE RAIL

Posted: Sun Aug 03, 2008 4:21 pm
by IanP
pest bird wrote:Does a 17 min scope rail equate to approx. 0.3 degres or to be precise 0.283 degres ?

I just need to make up some drop charts and the Barnard tapered rail's are 17 min.

Cheers
PJ

Barnard make a 17MOA and a 25MOA! I bought one from SARA and was told it was a 25MOA which I needed for my 223R. I measured it once I got home and calculated it to be 17MOA.

I wrote a little (28kB) MS Excel spreadsheet program to calculate the MOA of the sight ramp.The calculation only requires 3 measurements to be taken from the sight ramp.

To download the Excel file for the SightRamp Calculator follow this link and download the file.

http://www.mediafire.com/?j1zmlxhmg9s


Image

Posted: Mon Aug 04, 2008 10:21 am
by Paul Janzso
Thank you , Robert , Rod and Ian for the information, I have made up my drop sheets and now they are been put to the test with alterations/corections at each range.

Cheers
PJ

Posted: Mon Aug 04, 2008 9:21 pm
by Woody_rod
pest bird,

Can you post the charts for us to have a look at?

Charts

Posted: Tue Aug 05, 2008 11:05 am
by Paul Janzso
http://www.eskimo.com/~jbm/

Hi Rod

Here is the link I use , go into calculations, scroll down to balistic charts and add your info.

Cheers
PJ

20 MOA scope rail

Posted: Tue Oct 07, 2008 9:16 pm
by dhv
Newbie question;

If I want to set up a Sako 75 in 308 Win for F class, do I need a rail to elevate my scope or do most brands of scope have enough adjustment to cope?

If I need one, what brands are available for the Sako action?

thanks.

Posted: Tue Oct 07, 2008 9:57 pm
by stu_bear2002
G'day dhv, with some of the higher price scopes(eg:nightforce) you might get enough adjustment, I would probably suggest you get a tapered rail or at the least have burris rings with the 20thou inserts fitted.
Might i recommend a davies rail for $85 you can visit their website at http://www.daviestriggers.com.au/ i can assure you that adam and barry will look after you.
stuart

Posted: Tue Oct 07, 2008 10:36 pm
by dhv
Thanks. I understand Nightforce make them for Sakos as well.

Posted: Tue Jun 16, 2009 9:05 pm
by timothi3197
Ok this may sound stupid but: will I be able to use my .223 at 300yards still if I fit a 20MOA scope rail from Davies?

Would I be better with a 15 MOA?, I only want to get to 900m

Also does anybody have bullet drop tables for a .223 with the 80 grain AMAX? I have .308 only.- correction I followed your link PB and found it very useful.

How many MOA to a mil and visa a versa?

I have an Omark44


Thanks, Tim

Posted: Tue Jun 16, 2009 9:38 pm
by johnk
timothi3197 wrote:How many MOA to a mil and visa a versa?

Tim,

Believe me, you don't want to know. Radians & Milliradians are terms that the military uses to differentiate between themselves & real people. :roll: It's similar to two thirds of three fifths, but if you must try flagellation, go to http://en.wikipedia.org/wiki/Radian & http://www.snipercountry.com/articles/mildot_moa.asp

John

Posted: Tue Jun 16, 2009 10:24 pm
by AlanF
timothi3197 wrote:...How many MOA to a mil and visa a versa?...

1 mil = 3.44 min
1 min = 0.291 mil

Mil-dot reticles are about as useful for target shooting as rear spoilers are for front wheel drive cars :lol: .