Optimizing Precision And Accuracy From VLD Bullets By Eric Stecker

[Buffalobob]

So, if we have a 6.5/140/.287 SD bullet with the same SD as a 30/190/.286 SD bullet.
Both will penetrate the same then according to Buffalobob. Since both have the same SD.

Two bullets with the same sectional density but different masses will not penetrate the same on an animal. One only needs to consider a 17 caliber bullet striking a shoulder bone versus a 338 caliber bullet striking a shoulder bone (both with the same sectional density) to understand that there needs to be consideration of the mass involved in the impact.

One can examine a theoretical rifle that would fire a quarter (25 cent piece) either flat surface forward or edge forward to visualize that with the flat surface forward the quarter has low sectional density and will make a big raised welt but little else. If the quarter is instead fired edge forward then it will have higher sectional density and penetration will occur. So we see that the with the same mass, but different sectional densities, the penetration will change.

The interplay of mass and sectional density is something we should consider when selecting a bullet for a particular application.

 

[su37]

Two bullets with the same sectional density but different masses will not penetrate the same on an animal. One only needs to consider a 17 caliber bullet striking a shoulder bone versus a 338 caliber bullet striking a shoulder bone (both with the same sectional density) to understand that there needs to be consideration of the mass involved in the impact.

One can examine a theoretical rifle that would fire a quarter (25 cent piece) either flat surface forward or edge forward to visualize that with the flat surface forward the quarter has low sectional density and will make a big raised welt but little else. If the quarter is instead fired edge forward then it will have higher sectional density and penetration will occur. So we see that the with the same mass, but different sectional densities, the penetration will change.

The interplay of mass and sectional density is something we should consider when selecting a bullet for a particular application.

I'll have to disagree to a point with this one.

I'll maintain that different caliber bullets of the same brand and construction with the same SD shooting at the same speed will penetrate the same. The larger caliber will have a larger cross section (CS) to slow it down once inside the animal.

Outside of comparing extreme caliber dia. A 6.5 130 AB will penetrate just as deep
as a 30 caliber 180 AB. CS can negate the advantage of weight. The initial hit on the
animal will be harder no doubt with the larger caliber.

 

[JRinCo]

As a practical matter I chose the Berger 190 gr. VLD's for my .300 RUM, because I was able to load them in the magizine without using up space inside the cartridge. Thus far this load cleanly killed a 320 inch bull elk and 26 inch mule deer.

Yes the 210 grainers would be preferable but they are just enough longer, that they use up to much powder capacity when loaded from most magizines.

I have this combo loaded to 3390 fps using Retumbo, and have shot groups from the bench at 1000 yds. measuring under 8 inches, without any bullet failures. This was from a 1 in 12" barrel and it does work well in a 1 in 10".

 

[Titan]

This is a an excellent site and my first post. I don't know why it took me so long to find it.So hello to everyone.

Would I be right in thinking that Eric's sweet spot method would apply to most other bullets?

Regards...

..Titan

 

[BryanLitz]

Titan,
Hello and welcome to the site!

The 'sweet spot method' described in Eric's article will work best for bullets having secant ogives (meaning ogives profiled like the VLD) because they're the nose type that's most sensitive to seating depth. Other examples of secant ogives are: most of the Hornady Vmax and Amax bullets, the .30 cal 155 grain Lapua Scenar, and most of the JLK bullets.

Of course all bullets are sensitive to seating depth to some degree, but those having tangent ogives (nose meets bearing surface smoothly) are much less sensitive so the accuracy isn't related to seating depth as much as it is for secant ogives. Examples of tangent ogive bullets are: any Nosler bullet, most Sierra's, Berger's BT bullets, etc.

One commonly accepted reason for 'why' secant ogive bullets are more sensitive to seating depth is because that shape doesn't naturally self-center itself in the riflings as well as a tangent ogive, so it's more prone to tilting as it enters the riflings. As you probably know, a bullet tilting as it enters the riflings is bad for precision.

Hope this helps,
-Bryan

 

[Titan]

Bryan

Thank you for your welcome and concise explanation.

Regards..

..Titan

 

[7stw]

FIRST OF ALL i'D LIKE TO THANK ERIC AND BRYAN FOR ALL OF THEIR INPUT AND REPLIES TO QUESTIONS AND ISSUES. I AM PRESENTLY SHOOTING A SUPER ACCURATE 300 ULTRA MAG AND HAVE INTENTIONS OF USING YOUR 168 VLD HUNTING BULLET. AS I UNDERSTAND IT, MY RIFLE IS FREE BORED, JUST AS THE WEATHERBYS ARE. THAT BEING SAID, THE OGIVE OF THE BULLET IS QUITE FAR FROM THE RIFLINGS TO BEGIN WITH. I UNDERSTAND THE SWEET SPOT SETTINGS, AND UNDERSTAND THAT THIS IS A SECANT OGIVE. SO I GUESS THAT MY QUESTION IS, DO I START FROM MAX BOX LENGTH AND WORK BACK IN THE INTERVALS STATED IN THE OPTIMIZATION ARTICLE, OR DO YOU FEEL THAT MY OPTIMUM WILL BE AT MAX LENGTH. I HOPE THIS IS NOT A COMPLEX ISSUE TO CONSIDER. I'M SURE THAT MAX LENGTH WILL PROBABLY BE THE DEAL.

 

[Chas1]

Good article, thanks for posting. I'm going to have to give the sweet spot setup a shot and see what happens.

 

[Scot E]

Guys,

Any findings you would like to share regarding this new technique to find best accuracy with Berger VLD's?

 

[wardy]

FIRST OF ALL i'D LIKE TO THANK ERIC AND BRYAN FOR ALL OF THEIR INPUT AND REPLIES TO QUESTIONS AND ISSUES. I AM PRESENTLY SHOOTING A SUPER ACCURATE 300 ULTRA MAG AND HAVE INTENTIONS OF USING YOUR 168 VLD HUNTING BULLET. AS I UNDERSTAND IT, MY RIFLE IS FREE BORED, JUST AS THE WEATHERBYS ARE. THAT BEING SAID, THE OGIVE OF THE BULLET IS QUITE FAR FROM THE RIFLINGS TO BEGIN WITH. I UNDERSTAND THE SWEET SPOT SETTINGS, AND UNDERSTAND THAT THIS IS A SECANT OGIVE. SO I GUESS THAT MY QUESTION IS, DO I START FROM MAX BOX LENGTH AND WORK BACK IN THE INTERVALS STATED IN THE OPTIMIZATION ARTICLE, OR DO YOU FEEL THAT MY OPTIMUM WILL BE AT MAX LENGTH. I HOPE THIS IS NOT A COMPLEX ISSUE TO CONSIDER. I'M SURE THAT MAX LENGTH WILL PROBABLY BE THE DEAL.

Hello all...new to site and in searching older articles, found this one....can anyone tell me if this particular question was answered? I am wanting to switch to the Berger's but this is the exact dilema i have too.

Thanks. Steven

 

[Eric Stecker]

I can't share with you personal experience with a long throated rifle but I can relay some thoughts to consider. First, you have to decide if you are willing to single feed your ammo or use the magazine. If you are going to single feed the ammo your COAL can be much longer. You may find that your throat is long enough that even by single feeding you are still unable to get near the rifling. This is something that will be specific to your rifle but that still does not mean that the 4 COAL test won't work.

If you decide that you want to feed your ammo through the magazine then the distance to the rifling is less relevant. Your COAL will be limited by your magazine (no surprise to anyone there). This brings me to what I believe to be true for both situations.

The reports that we are getting show that each rifle has a sweet spot within the .150 range. We've focused on this range being near or touching the rifling because frankly this is what we are used to. There is a strongly likelihood that this range can be well away from the rifling and still include a sweet spot.

I will be very interested to hear the results from someone who tries this in a long throated rifle. I believe this can also be tried in a short throated rifle but using the maximum allowable COAL that will feed through a magazine as your "longest" measurement starting point. If anyone has a chance to give this a try I will be very interested to learn the results.

Regards,
Eric

 

[wardy]

Thanks Eric.......when I get some free time and some Berger's I'll try this out.

Steven

 

[wbaskins]

I guess I'm the strange guy in the room. I shoot a 300 win. mag. and I use the 168 grain VLD. I started out with this bullet and some H-4831 powder and slowly worked my way up the grain scale until I hit 3350 FPS. I shoot the Remington Sendero so I am able to seat the bullet just off the lands, and man is this thing a tack driver. This is by far the most accurate rifle I have ever owned, using this load. I have never had my bullet exit an animal, its total destruction inside, not a real great meat saver, but I haven't had to track anything either. My first kill was a Colorado mule deer at 400 yards, I could not believe how fast he dropped. The second was a bull elk at 700 yards and he went down so fast I thought I had lost him. I have killed deer from 75 yards out to 500 and shot elk from 100 yards to 700, all went down on the spot but I have never seen an exit wound. I'm not sure if its the small bullet at this velocity that causes no exit, but man do I love it.
Thanks Berger
Wayne

 

[Surculus]

I also shoot 168gr Berger hunting VLD's, but in a 7mm magnum. I dropped a cow elk last season at about 185 yards. She went about 30 feet, dropped, and did not get back up. When we got there, there was a neat entry hole but no exit hole. And no blood.

The rifle was a Weatherby Vanguard. During practice, the best I could do with the Bergers was 1.35 MOA. I thought it was the rifle because I have been able to dial in all my other rifles at less than 1 MOA. It was good enough for minute of elk, though, so I went hunting.

I am comfortable shooting the bergers out to about 400 yards. I would like to get out further so I was glad to see this article. I will do these tests and see if I can get sub MOA out of the 7mm.