Copper .30-06 ammo ballistic test

[gtita]

Hi,

I tested the Barnes Vor-TTSX (180 gr) against the Federal Trophy Copper (180 gr) and the Federal Trophy Bonded Tip (180 gr), and on my Tikka T3 LS .30-06. The test consisted in measuring bullet velocity at 3 yds and 100 yds employing a Chrony F1 chronograph. I then used the application iSnipe to recalibrate the ballistic coefficients in order to obtain a velocity curve consistent with my field results. Five cartridges per bullet and per monitored distance were used.

Resulting ballistic coefficients (within parenthesis values declared by the manufacturers) would be as follows:

Federal TC: 0.455 (0.523)
Federal TBT: 0.315 (0.500)
Barnes Vor-TTSX: 0.380 (0.484)

Muzzle velocities (calculated from the 3 yds data) were also different as by the manufacturers:

Federal TC: 2,770 ± 9 (2,700)
Federal TBT: 2,756 ± 13 (2,700)
Barnes Vor-TTSX: 2,615 ± 45 (2,700)

Velocities at 100 yds were as follows:

Federal TC: 2,575 ± 28 (2,530)
Federal TBT: 2,479 ± 71 (2,522)
Barnes Vor-TTSX: 2,393 ± 38 (2,520)

As the data show, velocity decreased more rapidly at 100 yds for Federal TBT (-9.9 %) than for Barnes VOR-TX (-8.2 %) and Federal TC (-6.9 %). Both Federal cartridges also grouped much tighter (within 1 MOA), compared to the Barnes (within 2 MOA).

Overall the test showed that Federal TC outperformed the two other bullets in terms of muzzle velocity, velocity conservation and BC. Both Federal bullets revealed a slightly higher muzzle velocity than the declared ones, whilst the Barnes had a lower velocity than the declared one. It is also worth mentioning that TC and VOR-TTSX are both wholly copper-made, while TBT has a lead core, which raises some environmental and health concerns.

Considering the prices of the Federal TC (39.99 $), the Federal TBT (39.99 $) and the Barnes VOR-TTSX (49.99 $), and the ballistic performances I will continue using my since ever first choice, i.e. Federal TC, for moose hunting.

[gtita]

I also add a picture comparing a selected number of recovered bullets of Federal TC and Barnes VOR-TTSX. They all hit a sand dune behind the target.

I noticed two main features. The first one concerns the general aspect with VOR-TTSX appearing more deformed and with expanding “petals” more easily torn apart. This let me wonder if they are more malleable than the TC. The second feature concerns the “boat tail”, which seems to be more pronounced in the TC than in the VOR-TTSX. This may partially explain the difference in the ballistic coefficients I measured in the field.

[Cowtown guy]

How do I test the BC for myself?

[gtita]

The easiest way is to measure the bullet velocity close to the muzzle (e.g. 3 yds) and at a distant range (e.g. 100 yds) employing a reliable chronograph. The obtained data can then be used in a ballistic calculator where the BC is "tuned" until the field data match the predicted velocity at 3 yds and 100 yds.

There are several ballistic calculators online. I normally use an iPhone application called iSnipe.

This method assumes that you are a sufficiently proficient and confident shooter for not destroying your chronograph when used at 100 yds!

I hope this helps!

[tony d]

Excellent informative test
Thanks
Tony

[sikwhiskey]

Originally Posted by gtita

I also add a picture comparing a selected number of recovered bullets of Federal TC and Barnes VOR-TTSX. They all hit a sand dune behind the target.

I noticed two main features. The first one concerns the general aspect with VOR-TTSX appearing more deformed and with expanding “petals” more easily torn apart. This let me wonder if they are more malleable than the TC. The second feature concerns the “boat tail”, which seems to be more pronounced in the TC than in the VOR-TTSX. This may partially explain the difference in the ballistic coefficients I measured in the field.

I find the Tipped TSX tends to expand a bit faster than the TSX. A bit more expansion with these Mono Metal bullets is a good thing, thats why Barnes recommends using lighter/faster bullets than you would normally use with lead/cup-core.
I have had great success with Barnes 180 TTSX out of a 300wm, MV 3000fps, never once found a bullet in an animal, even passing through 3 feet of elk. If I was to use the 30-06 with the ttsx, a drop bullet weight to 165grns would be in order.
I didn't know federal came out with a mono metal rnd, with a higher BC? Are these on the shelve's for hand loaders to roll there own? Haven't shot a big game animal with factory ammo in……. well…….. never. Weird!

[gtita]

Hi sikwhiskey,

I'm still a relatively "freshman" in shooting (and even much more in hunting), therefore I don't have the whole knowledge I find here. I didn't know that Barnes recommended lighter/faster rounds for TTSX than generally used. That's interesting!

I also don't know if Federal provides bullets for reloaders. I haven't started reloading (I'm studying for this!), but it could certainly be an interesting option from Federal. Their Trophy Copper cartridges are outstanding and very consistent from one cartridge to another, based on my tests and hunting results.

Actually, as for the latter I still have only one record out of my first and only hunting bullet that I shot straight to the nape of the neck of a ~700 lbs moose from 120 yds. The bullet went through the skull and lodged in the upper part of the jaw (this is what the butcher told me). It’s difficult to say what the bullet weight retention was, because I couldn’t recover it. However, it certainly went through at least 10 inches of thick skin, neck muscles, a vertebra, and very hard head-bones, thereby suggesting both, high weight retention and deep penetration power. I don’t know what would have been the behavior of the same bullet if I had aimed at the moose’s thorax. Given the relatively short range, I preferred the head for an immediate and “humane” takedown.

Thanks for your input!

[marxman]

the bc values between your observed and manufacturer claimed are grossly different. i see they use different factors to calculate bc g1 others although i dont know what the difference is. are their numbers wrong, are your numbers wrong, are you using the same factors what is the difference do you think.

[gtita]

Hi Marxman,

My understanding is that manufacturers declare “static” ballistic coefficient (BC) as opposed to “dynamic” BC. The former is estimated on the basis of theoretical variables associated with the bullet’s shape using reference models (e.g. G1). The dynamic BC is rather based on field observations of the bullet’s behavior, namely the evolution of its velocity and its trajectory curve. The dynamic BC is always smaller than the static BC.

If one applies the manufacturers’ static BC to a ballistic calculator, he will observe that the bullet’s trajectory (i.e. elevation loss) and its velocity evolution will not correspond to the predicted (theoretical) ones. I tried this at different ranges, i.e. 100, 200, 300, 400 yds. The real elevation loss was always greater than the theoretical one, of course including the meteorological conditions into the calculations. In order to find the reason of this observed behavior, I purchased a Chrony and started measuring the bullets’ velocities at muzzle (reverse-calculated from 3-yd velocity) and 100 yds range, and compare them with those announced by the manufacturers (Federal and Barnes). Bingo!

I believe that Federal choose to provide a slightly higher muzzle velocity (+2.6%) than the declared one in order to fit into a trajectory close to the one that would be provided applying their declared BC. However, the trajectory fits into the Federal’s predicted one within approximately 200 yds. Beyond this range, the real trajectory’s curve starts diverging from the theoretical. In the case of Barnes, bullets just fail to even achieve the declared muzzle velocity (-2.9%), but claim their declared BC as being estimated on the dynamic (field) approach, which may somehow justify the lower ballistic predicted performance compared to other similar cartridges. All this is truly a “manufacturer alchemy” that may be difficult to untangle and speculate on...

Nevertheless, in arguing on all this, I focus on ballistics and not on kill power that any cartridge more or less, but anyway, has. But I wish knowing how my bullets exactly behave not only after their impact on the prey, but also while they fly towards it. Manufacturers’ publicities focus much more on the latter, and provide numbers for the former (e.g. BC) knowing that the very large majority of people will not verify the underlying physics and maths.

Best regards!

[marxman]

okay... static ballistic co efficient haha! glad someone is on top of these things.

[Bushrat]

One has also to factor in that manufacturers reported BC's do not take into account the height of the scope above the line of bore. You could take the same bullet at the same speed zeroed at 100yds, with a scope exactly one inch above the bore will show a lower BC. Than if it were 1.5" above the bore. The bullet coming from the rifle with the lower mounted scope will strike lower at 200 -300 400 etc than with the scope mounted higher even though the bullet I has the same BC and velocity. That might explain your variance in BC from what the manufacturer says and what you are finding at the range, along with humidity and elevation above sea level, and other variations.

[gtita]

Bushrat, you raise good points. However, I actually made due corrections with regards to the height of my scope above line of bore (1.525”), as well as to the atmospheric variables (temperature: 12 to 22 Celsius degrees; humidity: 40-65 %) and altitude from sea level (less than 100 ft). I agree that these are all variables that may affect strike points at given range distances, but certainly not bullet velocity. At least, not to the extent I observed (for atmospheric variables).

[marxman]

Originally Posted by Bushrat

One has also to factor in that manufacturers reported BC's do not take into account the height of the scope above the line of bore. You could take the same bullet at the same speed zeroed at 100yds, with a scope exactly one inch above the bore will show a lower BC. Than if it were 1.5" above the bore. The bullet coming from the rifle with the lower mounted scope will strike lower at 200 -300 400 etc than with the scope mounted higher even though the bullet I has the same BC and velocity. That might explain your variance in BC from what the manufacturer says and what you are finding at the range, along with humidity and elevation above sea level, and other variations.

height of the scope is used to calculate the bullet path not the bc. on hornadys ballistic site you choose the height of line of sight above the bore and it will change the results for you. the bc stays the same. surely they arent going to throw in a factor like scope height that has nothing to do with bc into their bc claims. i was just on there yesterday i wanted to see the significant changes at 200 metres between cast, flatnose and flextip 30 30 bullets at the different speeds of cast and jacketed. it let me set the line of sight at 1 inch above bore for open sights i thought the whole thing was awesome making knowledge a lot easier but if the bc are not correct thats not very good

[gtita]

Just for fun, this is my range site at Îles-de-la-Madeleine (Quebec)...

[densa44]

We need more like yours. I have some questions too, but they are about the variance in MV of the different ammunition. Do you reload?

We have people here who do and can do much better than factory ammo, I can do better that what you have used but there are others who are near perfect.

What I would like to know, if we get MV out as a variable, get them all the same, will the BC still turn out the same or are there other variables we are not measuring.

I'll wait for some of our experts to lend a hand here.

It is people like you that try to get "real" data that will make us all more accurate shooters, thanks.

[gtita]

Densa44, as I mentioned here above, I don’t reload yet. I’m planning to do so but only after studying the art (I ordered a couple of books for this purpose). I truly am a neophyte here and have plenty to learn from you guys. But I believe that sharing key information is beneficial to everyone.

Just a statistical precision: the MV variation values I reported were standard deviations from the mean velocity and not variance values. Moreover, if I wanted to be the most precise in evaluating the BC, I should have measured muzzle and 100-yds velocities for same bullets, and then estimate individual BC values that could eventually be averaged in order to have one standard value for each bullet type.

Unfortunately, I only have one Chrony. Therefore, I proceeded with replicating velocity measures at 3 and 100 yds (5 bullets/distance/brand) and then use the average velocities for estimating the BC. Considering the yet small velocity variations between bullets of the same type/brand, I tend to believe that the ideal procedure I mentioned here above would have given very similar results to those I obtained.

Thanks for your attention and feedback!

[Bushrat]

Originally Posted by marxman

height of the scope is used to calculate the bullet path not the bc. on hornadys ballistic site you choose the height of line of sight above the bore and it will change the results for you. the bc stays the same. surely they arent going to throw in a factor like scope height that has nothing to do with bc into their bc claims. i was just on there yesterday i wanted to see the significant changes at 200 metres between cast, flatnose and flextip 30 30 bullets at the different speeds of cast and jacketed. it let me set the line of sight at 1 inch above bore for open sights i thought the whole thing was awesome making knowledge a lot easier but if the bc are not correct thats not very good

Understood, I was under the assumption that he wasn't using a ballistic calculator but rather calculating his BC from muzzle velocity vs drop of POI at various yardages thus the difference in BC of his calculations vs the manufacturers stated BC's without taking into consideration line of site, line of bore variation. Just trying to make sure sure he was aware, he only mentioned doing calculations from his field measurements. Obviously it's clear to me now he's aware.

I always take manufacturers BC figures with a grain of salt, some seem quite optomistic at times.

[marxman]

cool location i had to google it after seeing the strange alpine looking photo

[gtita]

Marxman, actually what you see on the backround are sand dunes, which are in part covered with maritime vegetation. Yes, it is a beautiful place in the middle of the St. Lawrence gulf!

[marxman]

i wonder if the ribs on monometal bullets cause significant drag that they conveniently dont factor with their g1 calcs

[gtita]

Marxman, according to Federal, the four grooves on the TC’s shank have two main purposes: (i) improve aerodynamics (i.e. BC), and (ii) allow reducing bore copper fouling. As for the latter issue, it seems that part of the bullet’s Cu-particles tend to accumulate within the grooves while it travels through the bore, instead of accumulating on the latter’s surface. The nickel-plated Federal TBT has only three grooves.

Interestingly the “boat-tailed” Nosler E-Tip bullets (.30-06, 180 gr) are also “mono-metal” (gilded), but they do not have grooves and are announced with an identical BC as Federal TC (0.523). I’m a little bit puzzled with all this issues.

I will certainly continue experimenting and build up key information to improve my shooting capabilities…

[marxman]

Originally Posted by gtita

(i) improve aerodynamics (i.e. BC), and

i dont see why improved aerodynamics means higher bc remember clinton did not have sex with that woman, and sure a schoolteacher doesnt belong on a space ship, but it wasnt in space when it blew up

[gtita]

In all of the three cases it is (or it was) a matter of friction, each with its own ballistic coefficient...

[sikwhiskey]

The groves on the shank of the bullet are to reduce friction in the bore. They allow the gilding metal on the bullet somewhere to displace while running through the rifling. Mono metals are long compared to lead core, and essentially need these grooves to counter act the friction caused by length. I haven't heard they are good for aerodynamic's, maybe. Would need some fancy equipment to test that.
Glad to hear federal learned from others (Nosler's) mistakes. I tried a pile of e-tips with poor results, high pressure and erratic velocities,not much for expansion, mid range loads for regular cup core bullets are high pressure with ETips..... As is now stated from Nosler.
I find Barnes BC to be very close, Noslers a bit high.
When taking the manufactures stated velocity for factory ammo, they may have got that with their test rifles, however, all guns are differnt, and will get varying results rifle to rifle, manufacturer's will tend to load down a bit to error with caution.

[purgatory.sv]

Is bc not a factor of construction?

After that don’t the other variables come into play?

[marxman]

Originally Posted by purgatory.sv

Is bc not a factor of construction?

After that don’t the other variables come into play?

apparently so as far as the manufactures would like to put it. but i would like to see bc as a number representing drag in flight, not as something by which the bullet makers would like to describe their design.

[gtita]

Marxman, actually the BC is tightly linked to the drag function. You may find interesting the explanations in the following Web site:

http://www.jbmballistics.com/ballist...unctions.shtml

I'm also struggling to grasp the all issue!

[marxman]

Originally Posted by gtita

Marxman, actually the BC is tightly linked to the drag function. You may find interesting the explanations in the following Web site:

http://www.jbmballistics.com/ballist...unctions.shtml

I'm also struggling to grasp the all issue!

more hooey of the type i thought you were trying to get around with your test

[marxman]

i saw a guy at the range last year using a computer program he downloaded off the internet called audacity. it timed the interval between the muzzle blast and the bullet strike sound off a piece of steel at 100 metres. he thought he was getting accurate velocity numbers out of it. of course they would not be muzzle velocity but an average speed out to 100 metres. i looked at the screen it had a line like a polygraph or something with spikes in it. anyway im sure a person could use this at 100 and 300 metres for bc calculations. this guy had no dedicated equipment at all, his laptop. his rifle and a piece of steel.

[sikwhiskey]

Originally Posted by marxman

i saw a guy at the range last year using a computer program he downloaded off the internet called audacity. it timed the interval between the muzzle blast and the bullet strike sound off a piece of steel at 100 metres. he thought he was getting accurate velocity numbers out of it. of course they would not be muzzle velocity but an average speed out to 100 metres. i looked at the screen it had a line like a polygraph or something with spikes in it. anyway im sure a person could use this at 100 and 300 metres for bc calculations. this guy had no dedicated equipment at all, his laptop. his rifle and a piece of steel.

BC's and Factory velocity, from factory are BS, They give you a starting point only. The only way to tell is to measure your MV and your drop at different ranges, then do the math……If you care. The biggest factor is wind, How is that a constant, unless your in a wind tunnel 500yards long? Again, Factory BC's are close, but not bang on…. The rest is open to operator err. or Atmospheric conditions . Not really worth worrying about. Shoot it out to what ever range and find out. Then write it down, as Atmospheric change……..then write it down again lol.
Keep your powder dry, SKW