VLD's vs Hybrid's

[Boisblancboy]

Is tuning for the hybrids vs the VLD's easier since they are less seating depth sensitive or am I way off base?

With the hybrid's do you start at the lands and work back or is there no need to since the hybrid design is more self aligning?

VLD's through the couse of barrel erosion are going to need adjustments to seating depth?

Thanks in advance. I read some articles about this but wanted to hear actually findings from you all.

 

[Rustystud]

This is my experience with Secant, Tangent, Hybred, flat based, boattail, and VLD bullets.

For less than 300 yards flat bassed secant bullets are the most accurate and easies to maximize their accuracy period. If a bullet will shoot .5 moa in a particular barrel 90% max velocity it can be further tuned by seating depth and powder adjustments.

Boattails in secant will be the second easiest to tune, again a stable load, is developed then tweeked by seating depth.

Boat tails in tanget are more difficult and more sensitive to seating depth.

VLDs are the most difficult to tune and often should be evaluated at 600 yards or more as they may do some stablizing in flight. My example would be a football that is thrown a little wobbly that smooths out into a nice spiral while in flight.

I have shot VLDs jammed .035" to jumped .110" ti depends on the barrel, throat, and bullet.

The three factors I find that make influences: neck tension, soft seated bullets adjust themselves to the rifling engagement thus making a single mode preasure spike. The degree of throat engagement has an effect on the pressure spike. And lastly bullet protrusion behind the neck shoulder have an effect on bullet alignment in engaging the rifling. In my experience bullets with the bearing surface seated behind the neck shoulder juncture tend to throw fliers. This is especially noted on VLD bullets.
Just my two cents worth.
Nat Lambeth

 

[effendude]

What Nat said +1
Scott

 

[Boisblancboy]

How about the hybrids?

 

[mtang45]

VLDs are the most difficult to tune and often should be evaluated at 600 yards or more as they may do some stablizing in flight. My example would be a football that is thrown a little wobbly that smooths out into a nice spiral while in flight.

Nat Lambeth

Nat, I'm not disputing your knowledge on the subject, I am wondering how that happens. I have watched alot of footbal and don't recall ever seeing a pass that started out wobbly suddenly straighten out into a perfect spiral.

Likewise, I'm trying to conceptualize the physics behind what would make a bullet do the same thing (I'm not a physics expert by any stretch). I know lots of people claim some bullets are better at long range than short for this very reason.

I'm not trying to hijack this thread, just expanding on, and looking for further discussion on the pitch and yaw of VLD's and how that relates to seating depth and shooting distance.

 

[1shot]

In regards to the hybrid bullets, I was one of the testers this past winter of the .264 140 gr. Hybrid. In my testing they were very tolerant of seating depth. I kept all other variables the same and varied the seating depth from .040 jam to .065 jump. None of the groups exceeded 1 MOA. This was done with out of the box and into the case bullets using a 6.5x284. The bbl. twist was 1-8’’x30” long and had just over 300 rounds through it when the testing started. (If memory serves me correctly). Having said that, they required about 2.50 MOA more to center up at 1,000 yards as opposed to the 140 VLD’s I normally shoot.
I hope this has been of some help,
Lloyd

 

[doc gordon]

good one for bulletologist litz

 

[Turbulent Turtle]

Nat, I'm not disputing your knowledge on the subject, I am wondering how that happens. I have watched alot of footbal and don't recall ever seeing a pass that started out wobbly suddenly straighten out into a perfect spiral.

Likewise, I'm trying to conceptualize the physics behind what would make a bullet do the same thing (I'm not a physics expert by any stretch). I know lots of people claim some bullets are better at long range than short for this very reason.

I'm not trying to hijack this thread, just expanding on, and looking for further discussion on the pitch and yaw of VLD's and how that relates to seating depth and shooting distance.

There are two kinds of instability issues in a bullet; static and dynamic.

The first kind is where the bullet will want to overturn and tumble on itself due to the air resistance and the fact the bullet is not uniformely balanced. This is what gyroscopic spin addresses and provided there is enough spin on the bullet, it will fly point on. A statically unstable bullet will keyhole on target and simply not fly true or far. A bullet may be on the verge of instability when it exists the muzzle, but if it remains point-on, it will actualy become more stable since its spin remains the same but the tendency to become unstable diminishes with its forward velocity. In other words, a bullet becomes more statically stable the further it flies. Until it goes transonic.

The second kind of instability is caused by flaws in the bullet which become apparent due to the bullet spinning on itself. If there is a bubble in the bullet or something else that causes it to be unbalanced, the spin of the bullet will cause the nose to start its one circular motion, very much akin to the badly tossed football discussed earlier. This can lead to stray shots and larger groups. This issue is far less common than it used to be because bullets are so much better theses days but it's also a reason to use just enough twist to get proper static stability and no more. Why spin the bullet more than needed and risk dynamic instability with an imperfect bullet?

There is a theory that some long, inherently unstable bullets take some time (AKA distance) to become stable in flight (go to sleep) and may exhibit "stability" issues at the short range but fly correctly later on. While I do not reject such a theory out of hand, I remain unconvinced that it is understood properly but I am always learning.

 

[boltfluter]

Now thats some great info. 8)

Regards, Paul

www.boltfluting.com

 

[BOBC]

I've had the same experience as 1 shot. Grouping with the VLD's at long range was about the same as the hybrids. But the hybrids needed about 2 minutes more elevation at 1000 yds. I was jumping both bullets. However, the VLD's did not have
the abrupt or pronounced juncture point at ogive to shank. The end of the ogive seemed to just blend into the shank. I believe the hybrids had a 12 cal ogive and the VLD's had a 17 cal ogive.
Both bullets grouped well but the VLD's shot flater at long range.
Bottom line is you gotta go with the one that gives you the best long range accuracy.
Bob C