Thread: G7 BC's

Originally Posted by Tussock

I imagine eventually Kiwi Greg will build something that actually fires a G1 standard projectile.

Till then Brian Litz G7s are probably the best option and then testing testing testing. Knowing what the number is helps if you plan on tweaking it a little.

Shooting to 500m and tweaking the BC to better fit your results may put you out, further out. Maybe not much, but maybe enough. It's ok as long as you know your tweaking your BC to suit your chosen range, and the atmospheric conditions you worked it out in.

I shoot with a droll little chap that likes to point out little things make little differences at range, and mostly little differences can be ignored. But, lots of little differences stacked together equals a big difference.

It is surprising how much the BC changes as the projectile slows down.

The big 375 projectiles are usually pretty good right out to 2000-2200 yards then it all turns to poos & you need to add more & more, 6moa from memory at 2500 yards, that is quite a bit nearly 4metres, at this stage I only have G1 BCs for them.

I guess the small ones do the same thing if you can be bothered shooting them far enough & can see the strike.

I have better results with Shawn Cs stepped G1 BC over Bryan Ls G7, with the 300 Bergers, there is very little in it until you way out there.

Die G1, die, die, die!

If I understanding the attached paper correctly it compares Litz vs companies, but assuming that Litz did it right?
If one compares Lapua computation (doppler/ measured all along trajectory) with a Litz calculation (estimated/measured at points of the trajectory) one finds discrepancies.

Originally Posted by Norway

Die G1, die, die, die!

If I understanding the attached paper correctly it compares Litz vs companies, but assuming that Litz did it right?
If one compares Lapua computation (doppler/ measured all along trajectory) with a Litz calculation (estimated/measured at points of the trajectory) one finds discrepancies.

What magnitude of discrepancies? Can you share the comparison?

Originally Posted by Tussock

I predict he will say a number of centimeters.

You will say it is too small to be relevant.

It depends

Originally Posted by Tussock

On how many centimeters?

Yeah. Pretty much. My ignoring certain things at certain ranges isn't unconsidered.

4-5 clicks

Originally Posted by Kiwi Greg

I have better results with Shawn Cs stepped G1 BC over Bryan Ls G7, with the 300 Bergers, there is very little in it until you way out there.

I discovered with 338 DCM in the weekend that I needed to use the G7, mainly I guess because with a muzzle velocity of 3450fps with the 300s, the G7 is a better fit than the stepped G1.

Swapping between G7 and G1 BC's on my 7mm RM with 162 Amax does not even account for a single click value out to 800yards on my ballistic app.

Does not seem to make real difference in my particular case until way out there.

G1 1500 yards 45.36 MOA
G7 1500 yards 46.08 MOA

Originally Posted by Tussock

Does it actually support G7 or did they just change the name and its still running G1?

I'm using Ballistic AE which uses the JBM computer and has all Bullet G1 drag models as well as Litz's G7 data

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