AusVarmint

Stuart Elliott had his best result ever at the 100 yard section of the Harry Madden Heavy Rifle event last Sunday.
His aggregate of .1556 is under the current record.
That agg started with a .088 group followed by four more groups in the ones.

His rifle is a Bat action fitted with a Maddco barrel, and using a 10-60x March scope.
30.5gns of BM2 under Berger "Column" bullets out of Lapua cases did the trick.

Wow that is fantastic shooting

Well done that man.

Amazing stuff well done.

Can I ask what Column bullets are?

Now that is impressive, 5 targets averaging 0.1556". Well done

MISSED wrote:Wow that is fantastic shooting

Well done that man.

I think he's been practicing!

Well done indeed.

Good effort, that has got to be impressive in anyones language.

stinkitup wrote:Amazing stuff well done.

Can I ask what Column bullets are?

I think Eric will explain it better than I can.

NEW – Berger 6mm BR Column Bullet

Posted February 28, 2012

There have been Bench Rest bullets in the past which were well-known for achieving consistently small groups over a wide tune range in many rifles and loads. One example of this was the Euber bullet. The seemingly ‘magical’ performance of these bullets has been attributed to special dies, stars aligning, owl feathers, or some other unknown influence. However, there are actually specific mass balance and aerodynamic properties which allow a bullet to mitigate dispersion and shoot precisely over a wide range of imperfect launch dynamics.

Understanding the physics behind dispersion mitigation, Bryan went to work creating a specific design for a bullet that had the widest and lowest tune valley. This means that the bullet shoots best in the widest variety of loads and seating depths. He came up with three different designs. Within each design, we made lead columns at three different heights in order to identify the truly optimal design. Over the next 4 years, Lou Murdica shot literally thousands of shots in the data capture phase of the project. When the smell of burnt powder cleared, there was one bullet left standing that was head and shoulders above the others in its ability to shoot well at the widest variety of loads and seating depths.

This bullet is the new Berger 6mm BR Column. You’ll notice that there is no listed weight. This is deliberate since the overall weight is not as important as the overall balance of the bullet, which is achieved with a specific internal lead column height. Due to slight variations in copper and lead material batches, one lot may weigh 64.8 gr while another lot might weigh 65.1 gr or 64.6 gr. So long as the column of lead is the correct height to achieve the desired balance, the overall weight is a by-product.

These bullets have already been used by Lou Murdica to win a Two Gun Agg in Florida. According to Walt’s Grandson and Plant Manager, David Hamilton, these bullets will be available by March 16th.

Regards,
Eric Stecker
Executive Vice President
Berger Bullets

Wow and I thought 2219 was the ADI powder of choice... thats a fantastic agg!

Brad Y wrote:Wow and I thought 2219 was the ADI powder of choice... thats a fantastic agg!

It can be...if your rifle 'tunes' to it. This powder is sold in the USA as H322.
Many BR shooters use Vitavhouri 133, and that powder is the number one choice in the USA.
The PPC is a very flexible cartridge when it comes to powder choice. I have had success with AR2207, AR2206 (not H), AR2219 as well as BM1 and BM2. For the major matches I tend to use the Vit 133, depending upon the weather. If it is over 30 deg I would give BM2 the nod.

The highest velocities are achieved with the Vit and BM2 - some shooters pushing the pills up over 3400 fps. Those velocities help with the wind, but are very hard on barrels and cases.

jimbo wrote: This bullet is the new Berger 6mm BR Column. You’ll notice that there is no listed weight. This is deliberate since the overall weight is not as important as the overall balance of the bullet, which is achieved with a specific internal lead column height. Due to slight variations in copper and lead material batches, one lot may weigh 64.8 gr while another lot might weigh 65.1 gr or 64.6 gr. So long as the column of lead is the correct height to achieve the desired balance, the overall weight is a by-product.

That's...interesting...I wonder how much tolerance they are putting on a batch weight if they are expecting a batch-batch "average" difference of +/-0.25g? Is there an effect on bearing surface, ogive or meplat dimensions or do these remain consistent within batch as well?

aaronraad wrote:

jimbo wrote: This bullet is the new Berger 6mm BR Column. You’ll notice that there is no listed weight. This is deliberate since the overall weight is not as important as the overall balance of the bullet, which is achieved with a specific internal lead column height. Due to slight variations in copper and lead material batches, one lot may weigh 64.8 gr while another lot might weigh 65.1 gr or 64.6 gr. So long as the column of lead is the correct height to achieve the desired balance, the overall weight is a by-product.

That's...interesting...I wonder how much tolerance they are putting on a batch weight if they are expecting a batch-batch "average" difference of +/-0.25g? Is there an effect on bearing surface, ogive or meplat dimensions or do these remain consistent within batch as well?

Aaron, I am thinking with Short Range BR, it is not an issue. Bit like weighing powder. It is becomes more critical as the distance increases.
Just my thoughts

Cam

Great effort Stuart. I hope you smash your own record soon.

RDavies wrote:Great effort Stuart. I hope you smash your own record soon.

I had to laugh when I saw "smash"; in context that would be like taking ten thousandths from .1556 to .1546

Insanely small group and definitely world class; a great job in anyone's language