Question for a ballistics program user

[Ian M]

Yesterday we shot 168 grain Sierras at 2700 fps at a very long distance. From the 100 yard zero I cranked the 16X MK4 exactly 65 minutes up, had to use 16 minutes of wind. We hit a rock that measured 20x18 inches after several tries. We walked the bullets out to the target rock - actually saw the bullets hit it but they did not do much to the rock.

Had 10 steel plates at 700 and we worked them over with seven different rifles, several were sporter weights. The heavy barrels clearly did better but we got respectable hit %'s with the sporters. Lots of good optics which help a lot.

 

[Brent]

I come up with 1480 yards with a 12.5 mph crosswind.

I still havn't made it out to shoot the rifles for a couple weeks now. I thought I'd have some gongs built by now but I just have to many irons in the fire. Maybe next weekend. Sure sounds like alot of fun your havin there.

 

[Ian M]

Brent,
Your program is right on - my Kestral wind meter was giving me 12 mph. We use 44 minutes at 1100 so I knew this was farther - poor little .308 bullets must be about pooped-out!
We have a bunch of steel plates, three thicknesses now. 0.5", 0.375" and 0.25". Just got the lightest stuff, plan on making four new gongs, 24"x48", will paint the outline of a deer's body on them. We will just shoot the 1/4" plates at 700 and longer, will have them angled to deflect the bullets into the ground. We are using some cheap saw-horse clamps that hold 2x4's, make a simple rack to hang the big plates on. Just got an old swing-set that is also good for hanging targets on. You are correct, we are having a bunch of fun - burning a lot of ammo and learning wind.
Thanks,
ian

 

[CatShooter]

Ian...

What program did you use that indicated 65 moa, and how much was it off in elevation, once you were "dead on".

CatShooter.

 

[Dave King]

Ian

CatShooters post forced me over to my computer and it looks like my program predicts 1320 to 1340+- yards and 12 mph. (1300 ft ASL, 59 degrees, BC .473 (but not much change for .500), 2700fps).

Get two GPS fixes ( shooter & target) in UTM mode and post the positions to get another check.

 

[Brent]

Dave,
how close can you get with that method?
The veocity I used was 2750 not 2700, the temp was only +20F, BP was 29.53 at 0' elevation and a BC of .462 so I screwed it all up that time.

A couple things I noticed when changing the temp was from +20 to +70, the 1480 yd zero moved to 1580 yds at 65moa and 1480 was down to 58.6moa, That's ALOT! Then when I changed the velocity to 2700, down from 2750 the zero moved from 1580 to 1545 yds with the 1580 at 67.7moa now.

Just thought this was interesting at this distance. I've never shot that far and haven't looked at the effects at this range much either, they are very dramatic indeed. Any time a spotter could be fired and seen hit it would make a huge difference obviously.

The swingset isn't a bad Idea, now where's my old one? Do you think the Kestrel 4000 is worth the $$$. They have them in Cabelas and look pretty sweet but they aren't cheap.

[ 05-21-2002: Message edited by: Brent ]

 

[Ian M]

I tried the big Kestrel and would stay with the 3000 - provides a lot of info and is very easy to use. Don't know about you but like to keep it simple, don't care about a Relative Humidity graph for the past ten days and whatever. The Kestrel 300 has been on several hunts and works fine, just have to remember that it only gives the wind speed where you are, not at the target.

Cat,
I wasn't sure how far out we were hurling, I don't use a computer program so was just looking for some info. We went up 65 minutes from the 100 yard zero and got hits on a fairly small rock. Fact is we walked the bullets out there, but started tickling it. When we shoot at 1100 yards on the steel buffalo I usually use 44 minutes with the 175's. I would expect we were over 1300, close to 1400 and getting hits.

Shot the Nikon Tacticals a bunch out to 7 & 800 and they are working beautifully. They are very good scopes - turrets are working perfectly, very bright and crisp images, everyone who has used them wants to buy one. Have one on a light weight titanium actioned Prairir Gun Works .300 Win. sporter with a brake on it to see how it stands up - 300 rounds so far and OK. Found out that shooting a rifle with a muzzlebreak from prone in a 12 mph headwind is not much fun, unless you enjoy eating dirt, grass, cowdroppings, assorted bugs and maybe a shell-shocked gopher or two.

 

[Brent]

Dave,
I got 1560 yds on the dot using your figures at a psi of 29.53, so something may be wrong with your program? I checked and double checked mine so........? Ian, could you run out and measure it off? hehehe. You must have posted while I was taking my sweet time eating and typing, editing the post before this.

All I need in a Kestrel is temp, wind and BP. No graphs and sub, sub, sub menus or other do-dads needed or wanted here. I just need to get this info.

The Oehler 43 I have needs the input for accurate BC and downrange velocity calculations too. The BP and wind meters are the ones I have to barrow from a friend right now who works on the North slope two weeks on two weeks off, kind of a pain when he isn't around. I can't find my Cabelas catalog so I don't know what features the Kestrel 3000 has.

 

[Dave King]

Brent

If I change altitude to 10,000 ASL I can get to 1580+- and 65MOA elevation but the 1100 yard range only required 34MOA up and not the 44+- that Ian stated and the wind dosen't work out correctly.

What comeup does your program predict for 500 and 1000 yards?

On the GPS thing, the error on distance will be about 20 feet or so I'd guess.

 

[Ian M]

Dave,
At 1100 we use 44 moa with 168's and around two less with 175's. The .300 Win mag and 190's is 32 moa. We haven't tried other calibers out there so that is all the come-ups that I have.
We have checked the 1100 yard distance a couple of times with lasers and it is very accurate - stood about mid-way and could get readings on the shooting shack and on the steel buffalo.
Good luck with your bear plinking.
ian