Es/SD difference NCC 105gr vs Berger vld match 105gr
- Thread starter blundby
- Start date
The composition of the Copper Jacket Material and the length of the Bullets,.. Bearing surface.
Found the exact same thing with, 6mm, Berger 87 gr. HVLD's vs 87 grain, V-Maxes when Chrono'ing my .243 win.
10 -11 FPS spread, on the Berger's and 25-30 FPS with, the Hornady's and they were, SLOWER !
SAME Components, otherwise.
Found the exact same thing with, 6mm, Berger 87 gr. HVLD's vs 87 grain, V-Maxes when Chrono'ing my .243 win.
10 -11 FPS spread, on the Berger's and 25-30 FPS with, the Hornady's and they were, SLOWER !
SAME Components, otherwise.
Forum Boss
Administrator
ES is certainly meaningful if you are shooting long range.
You do need to chrono a sufficient sample to determine the difference is truly a repeatable factor.
Along with bearing surface (as noted above), another subtle factor can be bullet diameter. We have seen 6mm bullet max diameter vary, among types, from 0.2427 to 0.2436.
You do need to chrono a sufficient sample to determine the difference is truly a repeatable factor.
Along with bearing surface (as noted above), another subtle factor can be bullet diameter. We have seen 6mm bullet max diameter vary, among types, from 0.2427 to 0.2436.
Last edited:
RegionRat
Gold $$ Contributor
@blundby As you gain experience with precision and accuracy, you will find that the difference in details like the specific mathematical ogive, bearing length, and base design, can all make a big difference in what it takes to tune a particular bullet. Differences in bullet diameter can mean that your gun likes some bullets and not others. Very loose fits are typically not going to contribute to accuracy.
It could be that your barrel will never shoot well with some bullets, or it may require a completely different charge or seating depth to find out. You may even find a bullet might only shoot with a certain powder and not another, even when they weigh the same. The effect on pressure and velocity from the "freebore" in a given ogive will make a difference in both group and velocity stats.
Start keeping track of the bullet geometry statistics. The VLD designs are often sensitive to seating depth. You will find a depth where that ES/SD and the groups close up most of the time, but not always.
It could be that your barrel will never shoot well with some bullets, or it may require a completely different charge or seating depth to find out. You may even find a bullet might only shoot with a certain powder and not another, even when they weigh the same. The effect on pressure and velocity from the "freebore" in a given ogive will make a difference in both group and velocity stats.
Start keeping track of the bullet geometry statistics. The VLD designs are often sensitive to seating depth. You will find a depth where that ES/SD and the groups close up most of the time, but not always.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.