Henson Aluminum Tipped Bullet Testing

[noel carlson]

AJ,

Thankyou for the kind words.

Best,
Noel

 

[Michael Eichele]

ME,

"WE DO NOT KNOW EVERYTHING ABOUT PHYSICS."...

I hate to be the bearer of disconcerting news, but nothing we are talking about falls outside the domain of classical physics, and the science at that level has not held any surprises for us since Newton. Fluid dynamics came later, but that is secondary to the fundamental points at issue in this thread.

Best,
Noel

How can you say that? The only physics we know regarding bullets are based on traditional bullets as we know them.

You cant know how these bullets are going to react. You can speculate but that is all you or anybody else can do.

Get off your high horse and move on. If you want to contribute to this forum, there is more than one thread. Contribute or move on.

 

[Lightvarmint]

James,

I'm not overly concerned with the aiming error for any individual shot, as a group of shots can be shot that will mathematically smooth out those errors in the data. Simply shoot a group, find the center and measure the vertical distance to the aimpoint. This is how I test loads and have documented this process with associated spreadsheets correlating velocity spreads with the vertical dispersion.

The thing I wonder about is the measurement method used to find the actual drops. I looked at the reticle you said you are using "NP-1RR" and couldn't figure out exactly how you were measuring 10.3-10.5 MOA since the Nightforce reticle pdf doesn't show a spacing that would easily allow you to measure to that precision.

In my estimation, this measurement method along with the aiming error could easily introduce more than 1moa of error into the the entire drop board/measurement process.

According to Exbal, a 1moa error in measuring a 300SMK at 338Edge speeds at 928yds is equivalent to a BC variance of .13. If the actual BC of the HAT bullets is .9, this measurement error could more than account for the reported BC's of >1.0. Even a 1/2moa error in drop measurements would account for the BC variance that some very knowledgable ballisticians on this board have questioned.

I don't doubt that these bullets have a BC of .9 or even .93 given the math that I've studied over the last couple of days (although it's been a couple decades since I've done any serious math). I also don't believe there are free lunches in physics. I expect that one of the following 2 reasons, or a combination of the 2 are responsible for the measured drops of these bullets.

1) They have a high BC (around .9+) and the math should be pretty easy to understand.
2) They are flying with a nose up attitude that causes them to shed velocity to support their better drop numbers. I hope this is not the case, as this will cause them to be more sensitive to headwinds/tailwinds/updrafts than other bullets. This will also cause them to impact the target with less than expected downrange velocity. Some downrange Chrono numbers would be a great help in determining if this is indeed the case.

AJ

ps: Noel, I read some of the stuff you've been focusing on with super high twist barrels and lathe turned bullets. Very interesting and complicated stuff. I for one appreciate your opinions on this board.

AJ,

What you say is possible and that is specifially whay we choose the aiming point that we do. Additionally, we do not read the center of the group or even the highest point in the group in an attempt to funish extra sunshine to the posterior of shooters and hunters..... We read the worst shot in the group. We advertise the worst case scenario vice the average or even the best...... That way when it is performed by others with their equipment and conditions, they should get more impressive results than ours.

The aiming error and reticle error would be the same for any bullet tested using the same equipment and that levels out the error of one bullet over another during side by side comparisons since the same equipment is used.

Since the last group was 3.5" then that equates to a resonable and acceptable shot dispersion and aiming ability for that amount of distance. FWIW, we have already discounted the potential group dispersion by only using the lowest shot in the grouping. Another good reason to use the worst case impacts.....

I don't know how they are flying that flat, but they do.... I am just reporting the RAW DATA for those who wish to calculate numbers to be used for comparison.... Folks that are truly interested (beyond the desire to merely debate) will respond by getting some and test them in their own equipment under the conditions that they see in their locale. The customer is the most important tester that uses these..... The danger is that all customers do not have the same equipement or ablities as each other and therefore they will see different results from one shooter to another.

Sometimes you have to interprelate scales.

The NP1RR has 13 moa of continuous elevation (+3 to -10) indications. It then has a break to the -15 moa mark.... So to prevent from having to read the impacts below the 10 moa point, we do not aim or read from the center of the reticle. If the projectile yields a trajectory less than 13 moa, it can be easily seen and recorded. Specifially, when the value is greater than .25 and less than .5 and that is what we reported. Specifically, we used numbers rounded to the nearest .1, that comes up to .3 to .4 as I have posted.

For example you can read a 10.5 moa drop using the +3 moa point and the area between -7 and -8 moa... You can also use this reticle to measure the size of inteneded targets at specific ranges. We do this to grade animals and to size up the antlers during our hunts.

As I posted above, these were the lowest shots in the groups.

I don't know how much experience you have with the NP1RR, but our experience started with them in 1994 when I traded some of the 338 Lapua precursor (30 Snyper) cases to Bill Shehane (Nightforce distributor) for a 12-42 Benchrest scope.

Another point that has not been broached so far and I will answer it in advance is "how do you know you are exactly on the same calibrated power level to read the shots in the reticle"... The answer to that is simple..... Instead of aligning the "dots", we use "scribe marks on the power ring and the scope scale. This allows for a much closer alignment of the numbers..... We got this idea from the vernier scale on micrometers. So all the testing is performed using the same marks on any scope that is not 5-22x. I typically try to use the 5-22s for all the target readings since they are the most repeatable and accurate...... Nightforce calibrates the 5-22x to the stop of the rotation of the power ring vice the actual mark on the power ring..... This is very advantageous when in the field under low light conditions. Just dial to the stop and you are exactly at 22x.

Your scope inquiries bring up another good point for shooters and hunters to consider..... Scope A at the 10 moa point MAY not be the same as scope b-z at the 10 moa aiming point. It is crucial to ensure you are using reticles that are either properly calibrated or their values verified by the end user...... As you can probably tell, I have a lot of interest in calibration..... Without it, the data (from anyone) on any subject is not as useful or accurate as it could be when using calibrated instruments that can be traced back to the associated prime standards...... I personally own two sets of Starrett-Webber Croblox gage blocks (grade 2) that are cablibrated. I verify my instruments before each and every critical measurement. I also eliminate measuring variables by using spring loaded comparator equipment whenever it is possible as this minimizes the affects of random and uncalibrated pressure on measuring instruments.

AJ, please do not take offense to this, but if you want some down range velocity numbers then you will have to shoot them out of your equipment. I don't have acoustic targets and when shooting at longer ranges you are just one undetectable wind condition away from a chronograph disaster.

I do know that some have armor plate at extended ranges to protect their equipment, but I do not. I have been flirting with the devil (chronograph) during the last few months. Nicking the chronograph is actually how we got started conversing with the DR. Ken. He was interested in our testing and made some suggestions that actually cost him some business. So, we feel that his recommendations were ethical in nature and we really appreciate his insight. He is a nice guy.

You will not find us "quoting" BC numbers of the Gen II bullets since we cannot get them directly from an instrument(s). However the Gen Is were easily determined by instrumentation and they were .770 for the 265s and .878 for the 280s...... As prevously stated, the newer Gen IIs are more sleek than the Gen Is and we expect better trajectory performance from them.

Buy them, test them, hunt with them, kill with them.

James

 

[BryanLitz]

.....

 

[AJ Peacock]

AJ,

What you say is possible and that is specifially whay we choose the aiming point that we do. Additionally, we do not read the center of the group or even the highest point in the group in an attempt to funish extra sunshine to the posterior of shooters and hunters..... We read the worst shot in the group. We advertise the worst case scenario vice the average or even the best...... That way when it is performed by others with their equipment and conditions, they should get more impressive results than ours.

The aiming error and reticle error would be the same for any bullet tested using the same equipment and that levels out the error of one bullet over another during side by side comparisons since the same equipment is used.

Since the last group was 3.5" then that equates to a resonable and acceptable shot dispersion and aiming ability for that amount of distance. FWIW, we have already discounted the potential group dispersion by only using the lowest shot in the grouping. Another good reason to use the worst case impacts.....

I don't know how they are flying that flat, but they do.... I am just reporting the RAW DATA for those who wish to calculate numbers to be used for comparison.... Folks that are truly interested (beyond the desire to merely debate) will respond by getting some and test them in their own equipment under the conditions that they see in their locale. The customer is the most important tester that uses these..... The danger is that all customers do not have the same equipement or ablities as each other and therefore they will see different results from one shooter to another.

Sometimes you have to interprelate scales.

The NP1RR has 13 moa of continuous elevation (+3 to -10) indications. It then has a break to the -15 moa mark.... So to prevent from having to read the impacts below the 10 moa point, we do not aim or read from the center of the reticle. If the projectile yields a trajectory less than 13 moa, it can be easily seen and recorded. Specifially, when the value is greater than .25 and less than .5 and that is what we reported. Specifically, we used numbers rounded to the nearest .1, that comes up to .3 to .4 as I have posted.

For example you can read a 10.5 moa drop using the +3 moa point and the area between -7 and -8 moa... You can also use this reticle to measure the size of inteneded targets at specific ranges. We do this to grade animals and to size up the antlers during our hunts.

As I posted above, these were the lowest shots in the groups.

I don't know how much experience you have with the NP1RR, but our experience started with them in 1994 when I traded some of the 338 Lapua precursor (30 Snyper) cases to Bill Shehane (Nightforce distributor) for a 12-42 Benchrest scope.

Another point that has not been broached so far and I will answer it in advance is "how do you know you are exactly on the same calibrated power level to read the shots in the reticle"... The answer to that is simple..... Instead of aligning the "dots", we use "scribe marks on the power ring and the scope scale. This allows for a much closer alignment of the numbers..... We got this idea from the vernier scale on micrometers. So all the testing is performed using the same marks on any scope that is not 5-22x. I typically try to use the 5-22s for all the target readings since they are the most repeatable and accurate...... Nightforce calibrates the 5-22x to the stop of the rotation of the power ring vice the actual mark on the power ring..... This is very advantageous when in the field under low light conditions. Just dial to the stop and you are exactly at 22x.

Your scope inquiries bring up another good point for shooters and hunters to consider..... Scope A at the 10 moa point MAY not be the same as scope b-z at the 10 moa aiming point. It is crucial to ensure you are using reticles that are either properly calibrated or their values verified by the end user...... As you can probably tell, I have a lot of interest in calibration..... Without it, the data (from anyone) on any subject is not as useful or accurate as it could be when using calibrated instruments that can be traced back to the associated prime standards...... I personally own two sets of Starrett-Webber Croblox gage blocks (grade 2) that are cablibrated. I verify my instruments before each and every critical measurement. I also eliminate measuring variables by using spring loaded comparator equipment whenever it is possible as this minimizes the affects of random and uncalibrated pressure on measuring instruments.

AJ, please do not take offense to this, but if you want some down range velocity numbers then you will have to shoot them out of your equipment. I don't have acoustic targets and when shooting at longer ranges you are just one undetectable wind condition away from a chronograph disaster.

I do know that some have armor plate at extended ranges to protect their equipment, but I do not. I have been flirting with the devil (chronograph) during the last few months. Nicking the chronograph is actually how we got started conversing with the DR. Ken. He was interested in our testing and made some suggestions that actually cost him some business. So, we feel that his recommendations were ethical in nature and we really appreciate his insight. He is a nice guy.

You will not find us "quoting" BC numbers of the Gen II bullets since we cannot get them directly from an instrument(s). However the Gen Is were easily determined by instrumentation and they were .770 for the 265s and .878 for the 280s...... As prevously stated, the newer Gen IIs are more sleek than the Gen Is and we expect better trajectory performance from them.

Buy them, test them, hunt with them, kill with them.

James

James,

Thanks,

Here is the NP-1RR reticle from the Nightforce site. I still don't understand how you are using it to measure, unless you are meaning the NP-R1 ??

AJ

 

[jmason]

Bryan,

Work like that certainly explains why, and where you are employed! I was glad to see that you used Eddybo's information as well since a lot of the people commenting in this thread seem to have missed or ignored it. I also appreciate that you pointed out the 265 HATS have a little performance edge to others in it's class within your testing. Looking forward to the rest!!

 

[eddybo]

Bryan, looking great so far when do you expect to shoot them? What rifle and what twist will you be using, what ranges are you going to be shooting?

 

[AJ Peacock]

I have concluded my modeling and report. It can be viewed here.

-Bryan

Bryan,

Well done. You mentioned the individual errors that could have caused the measurment errors. I believe it is likely a number of those errors adding up to the difference. The velocity is reported as Muzzle Velocity, but the Chronograph was likely somewhat in front of the muzzle (unless the Muzzle velocity was calculated for the Chrono being in front of the muzzle). Maybe the range isn't exactly flat, maybe the wind wasn't completely calm, maybe the zero wasn't perfect etc etc

I can see how a number of very small errors could radically impact the numbers. In no way am I implying that anyone (including LightVarmint) 'fudged' numbers, just that a number of smaller errors could have drastically impacted the results.

I thoroughly enjoyed your document. The calculated spin drift info was specifically interesting to me. I shoot the 300SMK in my 338AM (3250-3270fps, 4400ft elevation, 1:10" twist) and noticed nearly1/2 MOA of spin drift at 1415yds with a perfect zero at 735yds. I don't remember how many shots I wasted, trying to determine if it was me or an unseen wind (I had wind flags at the target and from my shooting position out to beyond 500yds). After i became completely frustrated, I sat down with a cup of coffee and realized it had to be spin drift.

Anyway, do you have calculated spin drift info for other .338 heavy weights? Specifically the SMK300?

Thanks,
AJ

 

[Lightvarmint]

James,

Thanks,

Here is the NP-1RR reticle from the Nightforce site. I still don't understand how you are using it to measure, unless you are meaning the NP-R1 ??

AJ

AJ,

All the information you are seeking is in the booklet that explains the the dots and lines.

Once you see it, you will probably understand it....

I now understand why you had the questions that you had...

You have to read the booklet and get the reticle information to break the code.

Top of the post is +3 moa

center is 0 moa

Bottom of the post is -3 moa

first dot is -4 moa

Top of the next line is -5 moa

bottom of the line is -7 moa

the next dot is -8 moa

top of the line is -9 moa

bottom of the line is -10 moa

That about covers the -13 moa of reference that I told you about.

James

 

[Lightvarmint]

Bryan,

Well done. You mentioned the individual errors that could have caused the measurment errors. I believe it is likely a number of those errors adding up to the difference. The velocity is reported as Muzzle Velocity, but the Chronograph was likely somewhat in front of the muzzle (unless the Muzzle velocity was calculated for the Chrono being in front of the muzzle). Maybe the range isn't exactly flat, maybe the wind wasn't completely calm, maybe the zero wasn't perfect etc etc

I can see how a number of very small errors could radically impact the numbers. In no way am I implying that anyone (including LightVarmint) 'fudged' numbers, just that a number of smaller errors could have drastically impacted the results.

I thoroughly enjoyed your document. The calculated spin drift info was specifically interesting to me. I shoot the 300SMK in my 338AM (3250-3270fps, 4400ft elevation, 1:10" twist) and noticed nearly1/2 MOA of spin drift at 1415yds with a perfect zero at 735yds. I don't remember how many shots I wasted, trying to determine if it was me or an unseen wind (I had wind flags at the target and from my shooting position out to beyond 500yds). After i became completely frustrated, I sat down with a cup of coffee and realized it had to be spin drift.

Anyway, do you have calculated spin drift info for other .338 heavy weights? Specifically the SMK300?

Thanks,
AJ

AJ,

--Velocity was figured back to the muzzle from 21 feet at the chronograph

--Range to the target verified by two Leica laser range finders as well as survey equipment when the land was surveyed for cutting the timber.

--Can't speak for the wind, but there were no indications of wind in the clover patch or leaves moving on the tree limbs... Additionally we have some bitter weed (dog finnel) that is a very good wind detector and they were not indicating wind at the target impact areas or along the bullet travel route..

The only thing that I cannot calibrate and verify is the electronics on the chronograph. I can verify the eyes by using the check channel, but the electronics cannot be verified....

Remember, for the chronograph to be the cause of an error, it would have to be reading low to cause the BC to shift up.

I seriously doubt that it is reading low at 3245 fps with the 265 grain bullet. I always thought it was a little on the high side.

We are going to develop a second control bullet loading to use to check the process of gathering the data that we already have on the HATS and the 300 SMKs....

We already have the field data on the 300 SMK at the same ranges and it matched Sierras published data for thier BCs. I have a lot of faith in that information since it is backed up by the company and they have not changed any of the published information for some time.

Since Bryan will not question the results we get using the Bergers, we will be using the 210 grain Berger bullets to verify the BCs as written on the bullet box and to use it as a second control bullet to validate our 300 SMK data that validated our HAT bullet testing that has already been performed...

All this has gotten me curious about the Sierra data being right on and supporting the HATS testing.........

I guess even if the Berger information is validated along with the 300 grain SMK data being validated some folks still not accept the HATS data. It will be much harder not to accept the HATS data when the Berger data is completed...

I really hope the Berger BCs come in within the tolerances for error.

But we shall see what BCs the bullets bear out in actual field testing.. The time for computer modeling is over for now.

James

 

[Lightvarmint]

I have concluded my modeling and report. It can be viewed here.

-Bryan

Bryan,

I realize that you do not have many of these to shoot, and I do not know what cartridge you are using. In short, they tend to shoot the best from .030 to .060 off the lands. Somewhere in there you should find a sweet spot that will allow you the achieve the accuracy within the limits of your equipment during your load develpment for your trajectory testing.

BTW what caliber and brand of test gun are you using?

Barrel maker?

Gunsmith?

Action?

Stock?

Good luck.

James

 

[Lightvarmint]

I have concluded my modeling and report. It can be viewed here.

-Bryan

Brian,

Interesting report. I was sort of hoping for the explanation to be lift issues but am thankful that we will not have to endure any stability issues due to nose up.

Anyway, thanks for doing it.

However, your report does contain some glaring errors, assumptions and assertions that are not true maybe it just due to lack of attention to detail. One of the major ones is that Eddybo has indicated to me that he may not have been zeroed within the adjustment capabilities of the scope at the zero point. Additionally, we were concerned that you would be unbiased and at the midpoint during the evaluation.... However with the errors we noted I don't know if that is now a true possibility. It seems as though you are "askew from the midpoint.

Additionally, you have not addressed the shooters who have developed similar drop charts and have taken game at extended ranges using the same BC determination method that we used with similar drop values.

The process for performing the tests on the HATS is the same as what we used to test the Sierra bullets as well as others and it is the same one we will use to evaluate the Bergers.

There were zero I repeat, zero issues with determining the drops through the scope... None at all. It is the same reticle that we use to shoot animals with and for some reason it is accurate for that. Additionally, it was accurate for the Sierra 300 SMK testing and validated their BC claims. The major reason to use the reticle vice a ruler or tape measure is to eliminate potential errors due to the aspect of the target board versus the shooter (muzzle of the firearm). You see the tape actually measures along the aspect of the target board where the reticle only sees the bullet impact in the vertical plane.

We have used similar tests to evaluate Lost River, GS Custom and Nosler bullets. The Lost river bullets exceeded their BC claims, the GS custom bullets flew like bricks and did not even come close to their claims..... Additionally when I corresponded with the owner and complained about it, he quickly removed the BC data from his web site... Finally, the Nolser bullets matched their BC claims.

I think we have eliminated every variable except for the electronics in the chronograph.

Just so that you understand, if the hunters who have taken game with the HATS in 265 would have used your coputer generated BC values, none of the animals would have even been hit much less harvested. The values in your report will not yield hits on the target at longer ranges. This is flawed for whatever reason the numbers don't match the the harvest results.

Hopefully the testing of the Bergers may shed enough light on the subject for you to believe the HATS trajectory results.....

Based on your experience, should I be jammed into the lands or experiment with them off the lands for the best performance?

Even better, is there any way to get some of the 338 Bergers to shoot side by side of the HATS to see what the drops would be out of the same gun on the same day under the same conditions with the same scope and shooter? For those with a "scientific" interest, this would be a great evaluation as well as a field test.

Hopefully you are willing to reciprocate and provide the same number of samples that were provided for your experimentation. You have to admit, this would be an interesting evlauation.

Let us know where to send the check for the 338 bullets.

BTW, I posted some tidbits that might help you on load develpement of the HATS since they cannot be approached in the same manner as the thinner J4 jacketed bullets. We did not know if Eddybo included those with his bullet shipment.

Good luck in your shooting.

James

 

[AJ Peacock]

Brian,

Interesting report. I was sort of hoping for the explanation to be lift issues but am thankful that we will not have to endure any stability issues due to nose up.

Anyway, thanks for doing it.

However, your report does contain some glaring errors, assumptions and assertions that are not true maybe it just due to lack of attention to detail....

James

James,

I was wondering if you would point out the glaring errors, assumptions assertions that aren't true. You probably read it more closely than I did, and I didn't notice any glaring errors or assumptions/assertions that appeared wrong.

AJ

 

[edge]

I have read this entire thread and find it very interesting.

However the machinist in me is very uncomfortable with the way the drops are measured!

A target board that was 10 degrees out of square and measuring a drop of 100 vertical inches would measure 101.5 inches on the board.
Any angle would be very easy to compensate for and I don't understand your complicating the drop measurements unnecessarily.

Even a tape measure would be more accurate than using a scope ( even three scopes ) and interpolating MOAs !

edge.