Ballistic table

[Niko-PG]

Hi,

After zeroing my M305 and shooting it up to 500 m I'd like to complete my ballistic table. I found lots of softwares to calculate the missing data but I'm missing some number : what the BC of the 147gr ball in surplus ammo (israel or portuguese) and the initial velocity ?
Any one made his own BT for the 305 with surplus ammo ? Can we share ?
Another question : what's the exact value of a MOA at 100,200,300 m ...up to 1000m ? I have some approx number but that's not enough.

Thanks

 

[maynard]

http://w ww.eskimo.com/~jbm/ballistics/traj/traj.html

Roughly 1 MOA @ 100yards is 1 inch, give or take a few thousands of an inch.
1 MOA at 300 yards would be 3 inches, give or take. So 1 MOA at 1000 yards would be 10 inches, give or take.
I say "give or take" as meaning, the slightest aiming error at 1000 yards or even at 100 yards will take up the few thousands of an inch difference. Add SD of your velocities and wind velocity will more them make up or add to the difference of a few thou.
IIRC the BC of a 147 grain bullet is about .430

 

[Niko-PG]

1 MOA at 300 yards would be 3 inches, give or take. So 1 MOA at 1000 yards would be 10 inches, give or take

I have these numbers but I don't like the "give or take" . That's because I'm shooting with the metric system (due to mildot scope+personnal pref) and these numbers "give and take" add a lot of imprecision to my conversion, that's why I'm looking for the exact numbers.
I'd like to have the "perfect" BT so I can say : it's due to my shooting !

thanks

 

[maynard]

I have set elevations for my target rifles that are written in stone. All the way back to 1000 yards using 3 different bullets, Sierra, Nosler and Lapua 155 gr. When I say written in stone that means that is the elevation I put on the sights at any given range to start with. Where the group forms on that particular day has a lot to do with light conditions, wind, tempreture and air pressure. It could be 1/2 to 3/4 MOA different than what it should be.
The ammo is the best match ammo I can make with everything weighed. The rifle and ammo will shoot 1/4 MOA or better elevation every day, when I do my part. This ammo is better then any match ammo I could buy and about 10 times better accuracy wise then any surplus ammo.
Does your M305 shoot less then 1 MOA with surplus ammo? I think if you can get surplus ammo to shoot better them 2 MOA you are doing great, buy a couple cases.
I am not trying to jump all over you here, but until you get to the range and test your rifle with whatever ammo you plan to shoot. And test at every range out to 1000 yards you will not know what your rifle will do. The MOA come ups will get you on paper, after that it is up to you.

 

[Niko-PG]

For now I shoot Israelian surplus ammo, doing 1.2 MOA at 100m but more than 6 at 500m. I don't think my gun needs more upgrade to be accurate enough up to 800m (military 1.75m target), I just need to finish my table.
I'm waisting a lot of time shooting, walking to the target, back to the firing line, ajusting, etc...( in fact I need an ATV)
I'm shooting surplus ammo for now : I need some training before waisting quality rounds.
That's why I want an "as accurate as possible" BT :to see if I'm progressing without running in circle trying to figure the wind correction.

Are you shooting 1/4 MOA with a M305 ??
Do you see a significative difference on your BT when you shoot surplus ammo (ex: same settings but ugglier group)?

Thanks

 

[maynard]

The rifle I am shooting is a bolt action GC Millennium with a 30 inch MacLennen barrel in .308. Iron sights, stocked in a CG Millennium aluminum stock. All shooting is done prone with a jacket and sling.
Knowing the accuracy of this rifle with handloaded match ammo, I compared it with some 7.62 IVI ball. It shot just over 3 MOA, all over the map.
You will not know how well you and your rifle are shooting until you start shooting match ammo. Once you start shooting match ammo your BT will be out the window anyway.
Ball ammo has never been known for accurracy.