264 twist rate and bullet choices

[Edd]

If you use the calculator on the Berger website, it takes an additional 2650 fps to compensate for the difference between an 8" and 9" twist. At sea level and 60°, the 140 gr bullet will stabilize at 2550 fps in an 8" twist and it takes 5200 fps to stabilize it in a 9" twist.

 

[rooster721]

If you use the calculator on the Berger website, it takes an additional 2650 fps to compensate for the difference between an 8" and 9" twist. At sea level and 60°, the 140 gr bullet will stabilize at 2550 fps in an 8" twist and it takes 5200 fps to stabilize it in a 9" twist.

That may well be, "on paper & in theory/mathematically" I won't argue that. Real world effect is another thing however**

Many things happen to a bullet as it passes through a barrel which alters everything "paper" is "figuring" The point is, higher velocities of heavier than reccomended bullets (within reasonable weight) like the 140gr vs 130gr in this case, do aid in stabilizing an accuracy.. longer barrels and I'm sure the different groove designs like that of the 5-R barrels and such also provide performance increases in their own ways as well. The 140's may be reccomended for 1:8 or faster, but many (including myself) are shooting them through 1:9's and having more than satisfactory results.. shoot them at 2550 like you are talking tho, and through say a 24" barrel that has 2000 rounds through it, then I'm sure you'll never stand a chance making the bullet shoot, nevermind stabilize.

At the end of the day, guys just have to go try and judge what they see for themselves.. they certainly can be loaded to shoot accurately AND stabil enough for long range hunting of any sorta big-game you so wish to pursue.

 

[Edd]

That may well be, "on paper & in theory/mathematically" I won't argue that. Real world effect is another thing however**

Many things happen to a bullet as it passes through a barrel which alters everything "paper" is "figuring" .........

What are some of those things?

 

[rooster721]

What are some of those things?

Computer programs cannot compensate for what the rifling does to Ballistic Coefficient after cutting the jacketing.. things change, BC *one... charts and "dope" therefore *two. Your downrange overall ballistics, *THREE.

I don't mean to judge or start any ****ing match.. but if you have spent any time at the range shooting different distances, you would understand that just because a bullets suggested BC is say: .612 ~ it doesn't actually mean your chart using that .612 is going to be absolutely correct in terms of your drops (because of what happens to the jacketing AFTER the rifling does its thing, to it) and that bullet leaves the muzzle.

For an example, in one rifle and one instance.. at a 2875ish velocity, the printed BC we used to come up with our chart was high. (again, remember the 3000fps velocity bullets BC's are based on) We had to adjust our BC down to make our drops and actual field results coincide with what our chart was supposed to be. In a second instance (in 4 seperate rifles this time, in our particular case) at velocities above 3000.. (3135 in one, 3175 in another, 3675 through a third and 3450 a fourth) ALL BC's actually had to be increased on the computer program to match true "dope" and what those bullets (and their impacts) were in fact flying to on our steel. To have any true chart match a load, it must be proven in the field.. this I am talking about is the way you prove it... every long range shooter keeping any sorta "dope" will tell you that printed charts (in the beginning of true chart developement) are only starting points...

Hopefully answering your question**