308 drop, confused with my data.

[hollywood]

Went and shot for the first time out to 300 yards. My data actual shot adjustments don't agree with any calculator or published data I have tried. Not sure if I am inputting data wrong or not doing math correctly. Here is what I got and what I shot.

RRA lar-8 20 in varmint

Muller erraticator 8.5-24 1/8 moa per click (advertised) @100

168 smk

2.810 coal

42gr xbr8208

Cci br2

Hornady match brass

Site height 2.5in

2538 fps average measured 13ft from muzzle

200yrd zero

100 yrd -9 clicks. 1.25 high

300 yrd. +36 clicks 13.5 drop

Info I have found shows with the 2538 mv or close to it should be around 2in high at 100 and 9in drop at 300.

What am I missing?

Thanks

[98Z5V]

If you really have 13.5" of drop at 300, with a 200-yard zero, then your calculations/clicks are off.

 

1/8th MOA scope.  1 MOA = 1.047".  Instead of 36 clicks, it should be 34 clicks, for a 13.5" drop at 300.

 

I can make the math work for 36 clicks, if I use 1/8 inch, instead of 1/8th MOA.

Edited April 26, 2013 by 98Z5V

[Zebra644]

Out of a 20" barrel 1:10 twist using 168 FGMM at 2520 FPS with a 100 yard zero, not a 200  I show a 5.5 MOA on my Night Force with 1/4 MOA adj. which is a 22 clicks for 17" of drop for a 300 yard shot. At 200 yards its 2.3 MOA or 4.8" inches low so a difference of 12.2 inches between 200 - 300 yards. I don't know if this helps or I made it clear as mud lol 

Edited April 26, 2013 by Zebra644

[hollywood]

Isint that still an awfull lot of drop from 200 zero to 300. Then it's not much from 200-100. 9 clicks 1.25 in. Most of the data says more drop from 2-1 and less from 2-3.

[hollywood]

Out of a 20" barrel 1:10 twist using 168 FGMM at 2520 FPS with a 100 yard zero, not a 200  I show a 5.5 MOA on my Night Force with 1/4 MOA adj. which is a 22 clicks for 17" of drop for a 300 yard shot. At 200 yards its 2.3 MOA or 4.8" inches low so a difference of 12.2 inches between 200 - 300 yards. I don't know if this helps or I made it clear as mud lol 

That is the data I expected or darn close.  It is not what i am getting, I dont know why it isint.  I know I have a good 200 zero set at "2" on the turret, up to 6.5 at 300 and down to .7 at 100 and that is dead on.    

[Zebra644]

  The only way it would change some is by using a longer barrel. That only gives you around 50 FPS per inch and a little bit more spin on the round. The 165-168 grainers start to destabilize and go subsonic at around 800 yds.  The 175 SMK that out service personal use are maxing out at 1,100 yds. They are even reporting confirmed kills where the bullet inter the bad guy almost vertical, with the nose of the bullet pointing at an angle towards the ground and the base towards the sky. An Army sniper shot a insurgent at about that range, who was standing out on a patio in an abandoned hotel say on the 5th floor, if memory serves, but don't quote me on that one lol. That bullet bullet weight will start dropping after about 250 yds. Its one of the reasons the U.S. military is looking into or has added  the 300 Win Mag into its bag of tricks. One other thing you can do is look at Remington , Winchester and Hornday's ballistic data and compare. 

[hollywood]

I've looked at a couple different data sources and all are very similar to what you said for drop. Which is why I don't know why mine is sooo different.

[Zebra644]

Well being in Vermont might also change things due to your elevation being in the mountains. Air density and bullet coefficient might be different from that at sea level or just above maybe? What part of Vermont are you in by the way its gorgeous up there. IS the 1/8 adjustment on your scope throwing you off also? One more thing, are you shooting level or are you shooting at an up hill or down hill angle. Any angle you shoot at will also add or subtract a few clicks for adjustment depending on the angle and gravity. There is a formula for that also 

Edited April 27, 2013 by Zebra644

[hollywood]

300-800 ft above sea level. Shooting flat. Half hour North of white river junction. I think my scope adj is off.

[edgecrusher]

300-800 ft above sea level. Shooting flat. Half hour North of white river junction. I think my scope adj is off.

Been there before, bought a race bike up there! You should call and see what the factory can do for you, what kind of warranty work they can provide

[hollywood]

Just need to figure out how far off it is exactly.

[Zebra644]

I've been through White River on my way to Stowe and Burlington I love Vermont especially the aged cheese yall have up there.

[unforgiven]

There was a huge outdoor museam outside Burlington it was all Americana.There was also a small choclate factory that was great.Took the ferry across Lake Champlain.Nice visit,then they went :cookoo: with the firearm laws. :rant2:

[planeflyer21]

Been there before, bought a race bike up there! You should call and see what the factory can do for you, what kind of warranty work they can provide

 

That's great they work on guns too!  <laughs>

 

800' won't make much of a difference.  We're at half of Mt. Washington's height when we shoot out in the desert here.  Drop isn't affected that much.

 

Jon

[racerken70]

I know its hard to find right now, but try to find some federal gold medal match. it seems to be the ammo by which all others are judged. and see if it shoots the same as your hand loads. and looking up mullers website it looks like your scope is 1/8 inch not moa which would make 98s math correct

Edited April 27, 2013 by racerken70

[edgecrusher]

That's great they work on guns too!  <laughs>

 

800' won't make much of a difference.  We're at half of Mt. Washington's height when we shoot out in the desert here.  Drop isn't affected that much.

 

Jon

knuckle head! 

[hollywood]

[hollywood]

1/8 adjustments. 7 1/2 per revolution. These were 2 revolutions to get to corners. Supposed to be 15 in box.

[unforgiven]

Groups look good bro.

[hollywood]

I think I might need to revisit the 300 yrd mark. I just smoked a woodchuck at 240 with my turret at my 200 yard mark. With what I had for data it should have hit way short of the critter.

[98Z5V]

Isint that still an awfull lot of drop from 200 zero to 300. Then it's not much from 200-100. 9 clicks 1.25 in. Most of the data says more drop from 2-1 and less from 2-3.

Getting back to this late, but...

 

That's not drop, with a 200 zero - that's RISE.  That's why it doesn't seem like much. 

 

With a 200 zero, your bullet is RISING through 100, and hitting 200. It's dropping after that, down to 300, 400, 500, etc...

[hollywood]

Contacted Mueller and they said it is 1/8 inch. Despite what the fact the mention both in there descriptions. Also said there tolerance is 1 moa which is silly being that the scope are inch adjustments. Took some talking to convince them something wasent right with the scope. Initially all they were concerned about was tracking and repeatability which wasent my concern. Then if there is a lot of adjusment made in elevation there will have to be some windage adjustment made due to the "internal erector tube being round and following a radius, which professional shooters know".

Finally someone else got the e-mails I think and said if the same amount of adjustment was made by both turrets the movement should be equal which slightly contradicts the previous statement.

Just hope the get it a lot closer to what it is supposed to be when I send it in.

[98Z5V]

Looks like that scope passed the box test with flying colors.  Good shootin', man!

 

That woodchuck took an assbeatin', too.  Nice.  <thumbsup>

[LR308]

Tested with 100 m zero:

Drop @

300 m 15 clicks

425 m 30 clicks

500 m 39 clicks

600 m 54 clicks

700 m 73 clicks 

800 m 98 clicks

900 m 124 clicks

1000 m didn´t make it.  :(

10 mm / click @ 100 m -> 0.1 mrad.

Gun: RRA LAR-8 Predator HP. Scope Vortex Viper PST 4-16 FFP.

Load; case Lapua once shot, bullet Lapua Scenar 167 gn, Powder Vihtavuori N150 45 gn and Federal 210 primer.

Edit: 802 m/s mv....

Edited May 7, 2013 by LR308

[hollywood]

Looks like that scope passed the box test with flying colors. Good shootin', man!

That woodchuck took an assbeatin', too. Nice. <thumbsup>

It passed as far as tracking is concerned but not for what the box is supposed to measure. It should have been a 15in square.