Please help with ballistic calc

[Bug Splat]

I'm trying to build a trajectory table for my 6.5-284. I'm without a chrono so I'm putting in as much information as a can and I'm using the bullet drop from 100 yards to 200 yards as my data to figure out my velocity but something is wrong when I plug it into JBM or Ballistic Tables. In order to replicate the bullet drop I'm getting, the software says it must be moving at 3350fps which is just not possible with this round without over pressure and even kaboom. Here is my data...

Bullet= Berger 140gr
BC= 0.595
Temp= 90*
Wind= zero for simplistic reasons
Zero= 100 yards
Scope height above center bore= 2.20
Powder= 47gr H4350

So, at 100 yards I'm at zero. At 200 yards my round impact 1.23-1.43 inches low. I'd have to be WAY over charging these rounds to get 3300+ speeds. Top shooters in the worlds with same barrel lengths (28") are using H4350 with 49gr and only getting 3050.

What is wrong with my data?

[ocabj]

You need to chronograph your load if you want to properly create a ballistic table with software.

Which Berger 140 are you using? .595 isn't listed in their updated BCs.

As far as impacting 1.25" low, that's a 2.5 MOA drop from 100 to 200, which is about normal for most any full power centerfire cartridge. If you're going to try to plug in numbers to generate a ballistic table without muzzle velocity, you'll need to get a couple more reference points. Shoot on a 300 yard target and a 500 or 600 yard target and get the drop.

[popeye4]

Quickload suggests you are running around 2850 fps......

[Bug Splat]

You need to chronograph your load if you want to properly create a ballistic table with software.

Which Berger 140 are you using? .595 isn't listed in their updated BCs.

As far as impacting 1.25" low, that's a 2.5 MOA drop from 100 to 200, which is about normal for most any full power centerfire cartridge. If you're going to try to plug in numbers to generate a ballistic table without muzzle velocity, you'll need to get a couple more reference points. Shoot on a 300 yard target and a 500 or 600 yard target and get the drop.

Thanks Ocabj, I'm going to see if I can bum a chrono from a friend soon. I'm using Berger Hunting VLD's. On the box it says the BC is .595. Could it be higher? I'll have to head out to BLM land to shot out beyond 200 and that could take some time. Thanks for the advice.

Quickload suggests you are running around 2850 fps......

See that's more what I was expecting to see. I wonder why the two programs I used were so off. Any chance you could send me the drop chart out to 1000 yards?

[tankerman]

Where are you located? I've got one you can borrow, if you're local.

[Bug Splat]

Where are you located? I've got one you can borrow, if you're local.

I'm in Santa Cruz. Thanks for the offer but I'm sure I can get one from my buddy in town.

I know my FPS should be around 2800 but when I plug it into my programs it shows a drop of 2.5 inches which I know is wrong. I've heard JBM Ballistics is good but now I'm not sure. Even the Ballistic Tables program shows the same data as JBM. I wonder if I'm entering something wrong into the programs.

[Bug Splat]