Henson Aluminum Tipped Bullet Testing

[jwp475]

This is what I was afraid of.

I never meant to cause this kind of friction, I only wanted to point out that a claim was being made that was way outside the bounds of what is considered normal, and we should consider that.

My intent was not to shift focus from one companies product to another. I'm simply raising a scientific inquiry. This (understandably) may be difficult to accept as I am an employee of Berger, however, I assure you that my curiosity in this matter is genuinely scientific.

-Bryan

Most will recognize this as a scientific inquiry , Brain and those of us that have followed you over time have found your integrity to be beyound reproach.

 

[Coues Sniper]

Most will recognize this as a scientific inquiry , Brain and those of us that have followed you over time have found your integrity to be beyound reproach.

Agreed.

 

[WildcatB]

Most will recognize this as a scientific inquiry , Brain and those of us that have followed you over time have found your integrity to be beyound reproach.

If there was ever a question about Brian's integrity, just remember that he is the person responsible for lowering Berger's published BC's. I'm confident he'd provide unbiased measured data.


Paul

 

[Lightvarmint]

If there was ever a question about Brian's integrity, just remember that he is the person responsible for lowering Berger's published BC's. I'm confident he'd provide unbiased measured data.


Paul

Hello,

I suspect he will since he indicated to me that he is going to order some to do some research with his 6-DOF formulas and programs.

After exchanging some PMs with him, I know for sure he does not doubt our trajectory results or any reports from other individuals...... In other words, he believes the trajectory evidence.

He just wants to find out why they behave in flight like they do. He has a hypothesis and is going to do some testing to see if he has the correct idea to explain the lack of bullet drop.

James

 

[Lightvarmint]

Hello,

We finally got some range time to test the 265s.

Before I go any further, I want to apologize to Kirby because I gave him a hard time about shooting drops for BC with the Aluminum tipped high speed and low drag bullet profiles..... Kirby I apologize. After conferring with Dr Ken Oehler about them he advised us to not use chronographs for bullets that do not meet the standard drag profiles..... These and the other ones that were made in Canada do not follow the current drag profiles that are available to me.

So, we shot some drops today. Back in December we zeroed the guns at 400 yards and then tested them at 600 just to get some trajectory information to use in the latter part of hunting season for meat expansion testing... The trajectory data was astounding and we decided not to publish it until we got some longer range drops performed.

Mr Eddybo obtained some numbers with his testing and seemed suprised at the results as we were with our testing results.....

Anyway, today we verified the 400 yard zero and then shot out to 928 on a vertical drop board. Todays results gave the same performance as the mid range testing back in December. Below is the range conditions and pertinant data. If someone could run these numbers and let us know what the results are, I would appreciate it.

338 Lapua Improved (My 1995 design with the 30 Snyper brass from Bell Labs)

1-10" twist

400 yd zero

265 gr

3245 fps at muzzle

2.13" sight height

69.6 degrees F

82% humidity

82' above sea level

29.84"Hg

calm winds... Impact points were about 1.5" to the left of the aiming point. This is well inside one click on the Nightforce 12-42 NXS scope.

At 928 yards the holes were -10.3 to -10.5 moa below the aiming point.

All the shots today were cold bore shots and they were about 10-15 minutes apart. We let the barrel cool while we went down to the target board and marked the holes. Group size was 3.5". We let the barrel cool while we went down to the target board and marked the holes.

Tomorrow the expansion tests will be performed at 928 on some phone books and newspaper I have been collecting for about 4 months.... This should not be a problem since the gun was grouping 3.5" at the 928 yard target board.
Thanks in advance for the help.

I think the 280s and the 300s will make our jaws drop open when we test them.

Hurry up RG and get me some 280s and 300s for drop testing.

James

Hello,

Above is the first posting and as you can see it has no BC mentioned..... Only data. Seems as though some did not see this in its entirety.

James

 

[jmason]

Hello,

I suspect he will since he indicated to me that he is going to order some to do some research with his 6-DOF formulas and programs.

After exchanging some PMs with him, I know for sure he does not doubt our trajectory results or any reports from other individuals...... In other words, he believes the trajectory evidence.

He just wants to find out why they behave in flight like they do. He has a hypothesis and is going to do some testing to see if he has the correct idea to explain the lack of bullet drop.

James

This is a good thing for Henson bullets!

 

[Lightvarmint]

This is a good thing for Henson bullets!

JM,

Yes, we basically have a phenomenon that cannot currently be explained by standard G profile and their associated calculations. There are not really any standard G profiles that fit the HAT bullets and that makes it both difficult to believe and hard to explain.

Believe me there is not anyone more skeptical of testing results than me. During my down time, we went out and got some additional instruments for checking bullets and one of them is the Starrett 673 micrometer that is very accurate (check the starrett website)..... When we started looking at some bullets available over the counter, we found out that they were not round....Some brands were not even close.

Anyway, I knew about the gawdy BC numbers back in December and I thought that it was freakish.... We were actually very leery about putting out those numbers so we waited until the spring testing. Even then(now), I only put out the raw data and let everyone else crunch the numbers using their computers and ballistic programs. That is why we have tested and then tested again. The results are repeatable and predicatble so that indicates that it is not a fluke. Coupled with some reports from shooters seeing very similar results substantiates the trajectory characteristics of the bullets..... Now for the "WHY".

Brian Litz is really interested in the "why" so he is going to buy some just like any other customer does with any other bullet brand and conduct his research to ascertain the "why". Once RG fills his current orders for the 50 BMG Aluminum tipped bullets and the high performace shotgun slugs he will be back in production of 338s and .30s and Brian will get his order when his name comes up on the production list.

On the way to do some spring testing, I broke a bone in the old foot and that delayed things for a while..... It also gave us time to crunch as much data and talk to folks about the bullet flight paths and impact points on the target.

Kirby had some similar experiences with testing he performed on some other branded Aluminum tipped bullets. He even made some posts about them and I believe it was back in 2007. His posts indicate he experienced the similar type of results that we have seen with apparent BC not matching trajectory predictions.....

FWIW, Dr. Ken Oehler knew that we were going to see some interesting results on the target board since the lower profile bullets tend to "sneak" (Dr Ken's term) through the electronic eyes of the chronographs at longer distances.

We know what we have.

We know what they will do.

But, we just don't know why it does it as of yet....

This is sort of like the situation with the engineering predictions for the ability of a bumble-bee to fly or even for the average person to understand how U-235 and some water (moderator) will create a reaction that creates intense kinetic energy and heat that can be harnessed for electric power generation......

Another point that gets over looked by the average citizen..... Does the electron "run" down the copper wire or is it bumped down the copper wire from the generation station to the end user. We certainly use electricity every day, but most cannot explain what creates it or how it gets transmitted to our electrical tools and appliances.....

Sometimes we as laymen can't "see" everything. Even after you have cross checked both the testing and evlauation processes as well as conducting tests over and over again, you just have to hit the "I believe button" when things happen exactly the same way over and over again that you cannot explain..... Then you go out and find the "why" and that is what Brian wants to do.

When you are shooting, do you ever think about how fast the gas has to expand or the pressure required to spit out a bullet from a barrel at 3000 fps.... Remember, you have your eyeball about 6" from the explosion/expansion/burn.....

James

 

[jmason]

JM,

When you are shooting, do you ever think about how fast the gas has to expand or the pressure required to spit out a bullet from a barrel at 3000 fps....
James

Never crossed my my mind, not even once. However the thought of getting my hands on some of those 7mm HATS has, and I'm patiently waiting.

 

[Lightvarmint]

Never crossed my my mind, not even once. However the thought of getting my hands on some of those 7mm HATS has, and I'm patiently waiting.

JM,

We wish the dies were completed and available but they are not as of now.

Once they get into RG's hands, I am sure the 7MM will become a top priority so that those shooters can prepare for their upcoming hunts.

James

 

[eddybo]

I do not know what the BC on these bullets will measure as, I am no ballistician, but am interested to see the results. I only know what number I plugged into exbal that works pretty well. I have not compensated for downslope of the areas where I am shooting and am not sure whether that will increase or decrease the number I am using. If Bryan wants some of these bullets for testing while his are on order I can send him some and he can replace them or I will sell them to him for what I paid.

 

[BryanLitz]

.....

 

[jwp475]

Bravo, Brain the science is fascinating to say the least

 

[eddybo]

PM me a shipping adress and I will ship them tomorrow. I will PM you my address where you can mail the check.

 

[Lightvarmint]

Eddybo,
I'll take you up on that. I'll need about 50 rounds for the tests I have planned. I'm happy to pay the going rate + shipping. Please email me ([email protected]) with your address to send a check.

As James mentioned, I'll be doing some detailed testing and analysis of these bullets including 6 Degree Of Freedom (6-DOF) simulation.

My hypothesis is that perhaps the bullets are flying with a nose high orientation causing them to generate some lift, and that's why they're able to shoot so flat. I know that conventional bullets don't fly like this, as they hit precisely where they're expected to based on a BC derived from time of flight. My thinking is that perhaps the large aluminum tips make a difference. If this is the case, the 6-DOF model will reveal the presence of lift, and explain why/how the bullets are able to shoot so flat. If this proves out, it will cause a challenge for modeling the performance of these bullets with conventional programs. The actual BC will not be 1.1, although it appears so based on drop. So what BC should a shooter use who wants to calculate performance? If you use 1.1 you might get the drop right, but you'll be way over estimating retained velocity, energy, and every other trajectory metric except drop.
If this is so, it's actually a good problem to have because the bullet is shooting flatter than a conventional bullet. Even if it challenges traditional calculation methods, the bottom line is the bullet may have enhanced performance.
If this lift hypothesis proves out, it can explain how James' drop observations are accurate, and that the bullet doesn't actually have a BC of 1.1 (even if the drop tests suggest it does).

This is an interesting learning opportunity. As I stated in the outset, my interest is purely scientific. If these bullets have a genuinely unique performance enhancing attribute, then I'm as excited about it as the next guy. I'm especially eager to understand WHY. Simply shrugging my shoulders and accepting a magic form factor of 0.301 without an explanation just doesn't sit will with me.

It will take a while, but I'll keep this thread appraised of my progress and report on my findings when complete.

-Bryan

Bryan,

I am going to be testing both the longer 280s and the longer 300s on the drop board shortly. If your theory is correct what is your prediction for the flights of these two longer bullets with respect to the 265s using the hypothetical theory?

Will it have a higher indicated BC, a lower indicated BC or, basically the same BC. The reason I ask is to see if the hypothetical holds true for the larger and longer projectiles.

I personally do not think it is the Aluminum tips or the rebated boat tails due to the fact that the Generation I versions (both had the same Aluminum tips and rebated boat tails) followed the G1 profiles with consitent predictability.

We measured them and compared them to Sierras and developed some rules of thumb for BC versus length (in a given diameter) and the anticipated BC was within .002 of what we calculated and predicted for both the 265s and the 280s. This was also the case in the Gen I .30s as well..... Although we missed the 180 BC by .005.

The big change between Gen I (12S) and Gen II is the nose profile and it is much more radical on the Gen II (15S). For the same weight bullet, we lost about .090" of bearing surface.

Looking forward to your prediction.


James