noel carlson
Well-Known Member
- Joined
- Mar 3, 2009
- Messages
- 214
Jon,
ZA30/5.8-W designation breakdown;
- ZA = Zethilius Associates
- 30 = caliber
- 5.8 = length in calibers (5.8x.30=1.74")
- W = bullet type (in this case tungsten core)
I am omitting the weight in the nomenclature, because when these are released there will be only two types in a given projectile length;
1 - The "M" will be a target solid, optimized for form factor.
2 - The "W" is a frangible optimized for both form factor, and mass. This is ideal for ELR, or for hunting. The shortest "W" projectile in each caliber series will be dimensioned for magazines, and twist rate compatibility with readily available, off-the-shelf, barrels. In the ZA30/5.8-W example, the 8.3" twist requirement is available from Hart (8.0"), Shilen (8.0"), Lilja (8.0"), and Pac-Nor (8.0" & 7.0"). If you want a cut-rifled barrel, Bartlein, and a few others will produce it on a special order. The 27 caliber twist will work for all 6 caliber, or shorter, "W" projectiles.
For ZA projectiles in excess of 6.0 calibers, a gain twist in a linear, exponential, or acceleration compensated, geometry is ideal... but they will spin the jackets off of conventional bullets, so you are committed to a dedicated system once this line is crossed.
If I have totally confused you, feel free to ask me about a specific bullet.
Mark,
Both the 175, and 240, should stabilize in the 8" twist, but obviously the 175 SG will be lower. A higher MV will add stability to this projectile.
P.S.,
I did not anticipate going into great detail in this thread on the ZA projectile specifications, and am not holding back information without cause. I will post photographs of these at sometime prior to the meet.
ZA30/5.8-W designation breakdown;
- ZA = Zethilius Associates
- 30 = caliber
- 5.8 = length in calibers (5.8x.30=1.74")
- W = bullet type (in this case tungsten core)
I am omitting the weight in the nomenclature, because when these are released there will be only two types in a given projectile length;
1 - The "M" will be a target solid, optimized for form factor.
2 - The "W" is a frangible optimized for both form factor, and mass. This is ideal for ELR, or for hunting. The shortest "W" projectile in each caliber series will be dimensioned for magazines, and twist rate compatibility with readily available, off-the-shelf, barrels. In the ZA30/5.8-W example, the 8.3" twist requirement is available from Hart (8.0"), Shilen (8.0"), Lilja (8.0"), and Pac-Nor (8.0" & 7.0"). If you want a cut-rifled barrel, Bartlein, and a few others will produce it on a special order. The 27 caliber twist will work for all 6 caliber, or shorter, "W" projectiles.
For ZA projectiles in excess of 6.0 calibers, a gain twist in a linear, exponential, or acceleration compensated, geometry is ideal... but they will spin the jackets off of conventional bullets, so you are committed to a dedicated system once this line is crossed.
If I have totally confused you, feel free to ask me about a specific bullet.
Mark,
Both the 175, and 240, should stabilize in the 8" twist, but obviously the 175 SG will be lower. A higher MV will add stability to this projectile.
P.S.,
I did not anticipate going into great detail in this thread on the ZA projectile specifications, and am not holding back information without cause. I will post photographs of these at sometime prior to the meet.
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