What makes a bullet accurate

[hybridfiat]

How many beers I had the night before...

I do wonder about the consistency of soft point manufacture, and the inevitable damage to the point that you see in the box, after loading, after chambering / rechambering.

Compared to a decent plastic tip, sometimes soft points look so bad you'd think they'd fly backwards. But it never seems to eventuate, a good soft point is an accurate bullet.

High speed photography has proven that the soft point on all high velocity projectiles is 'wiped' off just after leaving the barrel and now apparently it appears that most ballistic tips are lost too, due to friction.

 

[User00033]

High speed photography has proven that the soft point on all high velocity projectiles is 'wiped' off just after leaving the barrel and now apparently it appears that most ballistic tips are lost too, due to friction.

I have been googling looking for some video to show this but coming up with a blank, have you seen this? is it available on the interweb?

The plastic tip defamation I was aware of obviously with the advent of the ELDs from Hornady, and the considerable amount of money they have spent telling the world that AMax wasn't as good as they thought it was. But I admit that is the first time I have heard about soft points changing shape or disappearing altogether? Is that what we are suggesting? Does the projectile assume the profile of a hollowpoint, but with the opening still filled with lead?

 

[Miki]

High speed photography has proven that the soft point on all high velocity projectiles is 'wiped' off just after leaving the barrel and now apparently it appears that most ballistic tips are lost too, due to friction.

Not according to Mr Bullet of Nosler .. have you got access to these videos ?

 

[ChesterP]

Hornady have solved the issue with their new heatshield tips which have 2.5 times the melting point of other polymers used in most other polymer tipped bullets. Their tests revealed that with high BC bullets over a specified time of flight, temperatures of up to 800 degrees were being encountered which were effectively liquefying older polymers. This was much hotter than previously anticipated. I'm unsure of whether Sierra have followed suit but their green tipped TMKs seem to be ok, but it is easy enough to find out by flame testing a few in a flame of known heat, or by otherwise exposing them to high temperature in a controlled environment. A typical match for example burns with a flame temperature of 600 to 800 degrees, so three seconds (time of flight for say 1000 to 1200 yards) might be a rudimentary way to discover the answer!

However, I do believe that Sierra have in recent years changed the polymer of their own tips in light of Hornady's studies and certainly, Brian Litz's field tests on claimed BC with the TMKs tested certainly seems to back up Sierra's claims, as the claimed BC's are very close indeed to tested BC's indicating that aerodynamic efficiency is perhaps consistent with the tips maintaining form (ie not melting). I know that some crude field drop tests over various distances on some older V-max showed that claimed and actual BCs from Hornady, prior to the issues being addressed, were not consistent. Actual tests showed lower BC's than claimed. Mind you, this was G1 rather than G7 and I'm unsure if an averaged figure between velocity bands is how they define their figures. As with all individual testing, it's always wise to record your DOPE for longer range shooting for each load and calibrate your BCs according to drops and measured velocities.

 

[ejg]

The polymer tips I recovered from animals shot at 100-300m didn't seem melted but it might be difficult to judge if it was the impact that did some distortion . Some tips looked like new. I recovered Nos BT and Hornady from SST/A-Max.
Some polymer tips are manufacture lousy, strong sink marks showing a strong tendency for quantity over quality. Recon materials are sometimes skimped on too. One would not see the difference between a polyprop tip vs a polycarbonate or nylon tip with at least twice the melting temp.
edi

 

[paul o']

Ye gods there is so much to think about and worry yourself sick before you pull the trigger ! Now its after you have pulled the trigger ? , For my 2p , I do this test a few shoot more test a few more decided what one is best for you and you rifle, then enjoy what your doing and the rest will fall into place , I have moved to ELD & ELD-X I find them both with the same load have the the same POI , Only time will tell if its just BS re the tip melting off but I guess thou's of deer have been taken with the type of bullets we are now being told that they fall apart within a few feet of leaving the barrel so don't panic , in a nutshell if a gun go's bang & deer falls over then you have achieved what you set out to do ,The nut on the butt has to be in control ? if not the best bullets ever made even if made by fair maidens will just be as crap as any other makers bullets ???
Enjoy your sport .

 

[Laurie]

The polymer tips I recovered from animals shot at 100-300m didn't seem melted but it might be difficult to judge if it was the impact that did some distortion . Some tips looked like new. I recovered Nos BT and Hornady from SST/A-Max.
Some polymer tips are manufacture lousy, strong sink marks showing a strong tendency for quantity over quality. Recon materials are sometimes skimped on too. One would not see the difference between a polyprop tip vs a polycarbonate or nylon tip with at least twice the melting temp.
edi

As ChesterP says, it's a flight time / distance issue. The old A, V, and SST tips won't have been affected in 200-300M shots, but it was an issue for those bullets that might be used at 500/600 plus. IIRC, Hornady hasn't changed all its bullet tips, only those on long-range designs as a result of their findings.

 

[sh1kar]

Whole raft of videos on this page

S

 

[sh1kar]

And.....
Whether you agree with the ethics of long-range hunting or not, it is a massive trend, and bullet manufacturers are engineering purpose-designed hunting projectiles to meet the exacting demands of hunters who want to shoot distances that would flabbergast their great-grandpappys.
Why would you need a special bullet for long-range hunting? For three primary performance characteristics:
Accuracy is one. Match-grade bullet consistency is critical if you are attempting to put your first shot squarely through the vitals at distances of a half-mile or more. Typical big game bullets don’t offer sufficient levels of consistent accuracy for long-range hunting. We’re talking the kind of precision that helps competitive shooters win championships at Camp Perry.
Aerodynamics is another. Typically termed ballistic coefficient (BC), a bullet’s ability to flow through the air with minimum friction is critical. A high-BC bullet maintains its speed much longer, resulting in less downrange drop, more downrange energy and less downrange wind drift—all critical to long-range hunting performance.
Last, and most difficult to achieve, is a wide impact performance window. Ideally, a bullet will expand fully and penetrate deeply at very low velocities, making it capable of killing cleanly when long-range hunting, yet won’t fragment into nothing and fail to penetrate at very close-range, high-velocity impacts.

From left to right: Hornady ELD-X, Nosler ABLR, Berger VLD Hunting and Barnes LRX.​

Yet such a bullet is very, very difficult to engineer, let alone produce, especially to the levels of consistency that enable match-winning accuracy. Broadening the velocity window within which a bullet will expand yet hold together is every hunting-bullet company’s holy grail.
But this article isn’t meant to be a philosophical discussion of what makes a great long-range hunting bullet. It’s a quick-and-dirty look at four different bullets specifically pegged for long-distant work. As you’ll see, each of them posses the three vital characteristics in varying degrees.
In alphabetical order, here are four great purpose-built long-range hunting bullets available today.
Barnes LRX
The Barnes LRX is a homogeneous bullet, meaning it’s made out of one solid material, which happens to be copper. It has only one weakness: Since copper has less mass than lead, LRX bullets are inherently lighter than a lead-cored bullet of the same size, resulting in somewhat lower BCs.
Where the LRX really shines is bullet integrity. It will expand reliably down to 1,600 fps or a bit less and up to, well, however fast you want to shoot it—and that’s where the real magic happens. Even if the four copper “petals” that expand outward and roll back into the classic mushroom shape on impact shear off of the main shank, it’s impossible to batter that shank too small to penetrate.
It will always drive deep, and even if you only have a .284/7mm-diameter blunt-fronted shank pounding through heavy bone, dense muscle and vital organs, it will penetrate and kill.

Additionally, if some or all of those four petals shear off, they become satellite projectiles and wreak their own share of havoc. In fact, according to Lead Ballistician Thad Stevens, Barnes is intentionally engineering more and more of its hunting bullets to lose petals during penetration.
Personally, this is the only purpose-built long-range hunting bullet I’d trust if I had to shoot a big moose quartering to me at very close range, and count on it to drive through that massive shoulder and go killing-deep into the vitals.
As for accuracy, while it’s frankly not a match-grade projectile, the LRX tends to be very forgiving through a broad selection of rifles. I’ve had Weatherby and multiple custom rifle makers tell me that the Barnes bullet is their go-to when qualifying rifles for an accuracy guarantee. Whether that guarantee is one MOA or a half-MOA (which I’ve personally seen many LRX loads achieve) that is a resounding accolade to Barnes bullets.
Berger VLD Hunting
The Berger VLD Hunting bullet is, without doubt, the most popular and most controversial “long-range hunting” projectile available. It’s also the only one that wasn’t originally engineered for long-range hunting. It was originally a match bullet and a very good one. That tells you all you need to know about its accuracy potential, but I’ll add this: the VLD Hunting is probably the easiest of all four of the bullets featured here to get to shoot well, meaning it’s very tunable and responds exceptionally well to careful handloading.
It’s not uncommon for very accomplished, meticulous handloaders to achieve legitimate half-MOA accuracy from their precision rifles (legitimate meaning repeatable; they can produce such groups on demand), but the Berger will occasionally provide consistent quarter-MOA accuracy in a very good rifle. It also offers very good BCs.

The VLD became a long-range hunting bullet when some erudite soul discovered that it absolutely pounds thin-skinned, deer-size game. On impact, the bullet tends to grenade, the nose riveting rearward and the soft lead core blowing out the thin-jacketed base. With little or no shank left to penetrate deeply, the fragments dump 100 percent of the energy carried by the bullet into the wound, turning internals into scrambled eggs. With a good hit, the result tends to be instant lights out.
One weakness plagues the VLD in long-range hunting, and that’s the lack of penetration when penetration is really needed. I have three friends, experienced handloaders and hunters, who have gotten into nightmare skirmishes with well-shot animals when their Berger bullet failed to penetrate through a shoulder and into vitals. Big animals with heavy muscle and bone are most liable to such rodeos.
Hornady ELD-X
The Hornady ELD-X is the newest of all the bullet designs, and it is very good indeed. Hornady holds ELD-X accuracy standards to the same high level as its superbly accurate A-Max match bullet. I’ve shot my best-ever groups at 200 yards and at 1,000 yards with the 175-grain 7mm version.
Interestingly, when a polymer-tipped, high-BC bullet is fired at high velocities—let’s say over 2,800 fps—it builds excessive heat in its tip, and the tip begins to erode. Aerodynamics suffer. (Standard-BC bullets don’t experience the phenomenon because they don’t maintain super speeds long enough.) Hornady researched and implemented a new, thermally resistant “Heat Shield” tip on the ELD-X and generated superbly accurate BCs via Doppler radar.

So, accuracy is superb, and BC numbers are both enviable and dependable. What about impact performance?
Hornady is actually rather modest and advertises a velocity performance window ranging from 1,600 fps to 3,000 fps. The ELD-X’s core is not bonded to the jacket, because engineers couldn’t achieve satisfactory levels of accuracy when they began bonding prototypes. Rather, the core is of a relatively strong lead/antimony alloy to prevent excess fragmentation, and it is mechanically locked to the jacket via Hornady’s traditional Interlock system.
At close range, especially from magnums, it tends to lose a lot of weight and sometimes the core and jacket separate at the end of the penetration path. However, it still penetrates adequately, and it always kills quickly. When using it for long-range hunting, it opens with absolute perfection.
Nosler AccuBond Long Range
No company is better at core-to-jacket bonding than Nosler, and the AccuBond Long Range is a bonded bullet. To bond a bullet, typically the core must be pure lead or a quite-soft alloy, so the ABLR’s core is soft and may “smear” off the front of the expanding mushroom-shape but it will never separate from the jacket.
The ABLR also features a thick jacket base. It’s worth noting that the thicker a bullets jacket is, the more difficult it is to produce consistently.
Advertised BC numbers for the ABLR are high. Very high. Candidly, they’re optimistic, but even after knocking them down a bit while shooting long-distance trajectory-validation tests, they’re still fairly high.
My twin brother’s custom .300 Winchester Magnum and a good buddy’s Desert Tech .260 Remington love the bullet. They both achieve half-MOA accuracy. However, I’ve personally struggled to achieve that level of accuracy in the handloading I’ve done, and I’ve tried a lot.

It’s just a theory, but I believe that Nosler’s engineers maximized aerodynamics to the point where forgiveness is low, knowing that most long-range shooters are OCD enough to finesse handloads this way and that until they achieve precision. Plus bonding—being another step in the bullet-building process—unavoidably introduces variation.
Finally, the difficulty in manufacturing thick jackets with perfect consistency also challenges accuracy. Without doubt, the bullets will shoot superbly out of the right rifle/handload combination, but for me the ABLR is not an easy-accuracy projectile.
Nosler suggests that the ABLR will perform all the way from 1,300 fps up to 3,200 fps. My take is this: It will certainly kill anywhere within that range, but I’d expect minimal expansion up to about 1,600 fps and almost complete bullet fragmentation at 3,200 fps. Still, that’s pretty admirable performance for a long-range hunting bullet.
Summary
Me, I’m happiest when my long-range hunting bullet impacts at somewhere between 2,000 fps and 2,800 fps. At those speeds, I know that any one of the bullets featured here will expand dramatically and cause massive internal hemorrhaging, yet will maintain enough weight to penetrate at least through a broadside elk.
Which bullet do I pick? Depends on the situation.
If moose is on the menu, without question the Barnes LRX. If I’m using a cartridge that is of marginal size/energy for the game at hand (for instance big bull elk with a 6.5 Creedmoor), the Barnes is also the way to go.
If I want sub-half-MOA accuracy and extremely high BCs for maximum reach, the Hornady ELD-X or Berger VLD Hunting.
If I want a long-range hunting bullet that will provide adequate, predictable terminal performance from 10 yards to 1,000 yards, the Hornady ELD-X or Nosler AccuBond, whichever shoots better through my rifle.



Read more: http://www.rifleshootermag.com/ammo/great-bullets-for-long-range-hunting/#ixzz4sexocM17

 

[rem284]

The nut behind the but

 

[Laurie]

Assuming a bullet is competently designed and also assuming a viable spin rate is achieved through the barrel's rifling twist pitch to stabilise the bullet fully, there are three factors that affect bullet performance so far as groups sizes (dispersion) are concerned:

1) Nose / ogive type. Traditionally, Sierra, Speer, Lapua, Nosler et al used relatively short, blunt and tangent ogive noses on their bullets, whilst Hornady used a 'mild' secant form on most of its bullets. Tangent ogive designs are easier to 'tune' (largely in terms of COAL / 'jump' to the rifling) than secant types albeit Hornady's secant bullets were so mild that this wasn't a great issue. A jump-tolerant design usually simply shoots well at various settings / speeds assuming the bullet to barrel match is OK. Early Berger long-range designs were all 'aggressive secant' long-nose VLD designs. These are much harder to tune but reduce in-flight drag. While they were all for match shooters that didn't affect stalkers, but the rise in very long-range live quarry shooting in some places and circumstances has seen a marked shift from high-drag easy to use designs to low drag 'finicky' models with Berger redesignating some its range as 'Hunting VLDs' and everybody else following with super long-nose high-BC designs options.

2) Bullet to barrel compatibility. No matter how well designed or made, if the bullet and barrel dimensions don't suit, the results won't be great. An extreme example is GB and Commonwealth 'Target Rifle' from 1968 to the Millennium where the use of military-spec 7.62mm NATO ball was the norm. Not only is the 7.62 not quite the same as 308 Win needing a modified chamber, but the bullets were markedly undersize compared to 308 Win - as small as 0.3073" (compared to the nominal 0.3080" in SAAMI 30-calibres, and often actual 0.3082-0.3083" for commercial American or European bullets). As a result, TR rifles used 'tight' barrels, some very 'tight' indeed such as those Number 4s rebarrelled with late 60s and 70s RSAF Enfield Lock hammer forged heavy barrels designed for the British forces L39 and L42 target / sniper variants of the Number 4 rifle. Bores aropund 0.294 or 0.295" (v the nominal 0.300") and smaller groove diameters were the only way to make these rifles shoot acceptably with these bullets. It's also one reason why many commercial 308 Win sporting or match rifles gave so-so or worse precision with cheap surplus milspec 7.62 ammo.

There is variability between makes in some calibres, especially 6mm for some reason. Two sets of 6mm barrel dimensions are available from the US custom barrelmakers and people may choose one or other on the basis of the make / model of bullet to be used. More an issue for the extreme precision match shooter than the sporting rifleman though.

3) Manufacturing quality and consistency. It is very easy to make poor bullets and difficult to make good ones. Components - the gilding metal jackets and the lead alloy cores have to be very well dimensioned and consistent to get small groups. The bits have to be put together by people who really know what they're about and do it the same way bullet after bullet. That's why even today, top short-distance BR shooters use handmade bullets from small output producers. The only such UK producer is G&C Custom Bullets in Hampshire

http://ukvarminting.com/forums/topic/21107-g-and-c-bullets/

Even so, custom bullet makers buy in the unformed jackets and if you cannot get high enough quality, you can't make the best. Berger Bullets bought the best mass maker of BR quality jackets in the world, the makers of J4 products and it is a key part of Berger bullets quality. If the lead core and the jacket are not made to very high consistency, the bullet will have a marginally thicker jacket on one side than another and that makes it heavier on that side resulting in the bullet's physical axial centre and centre of gravity not being the same. Under spin, the bullet will always veer towards an imbalanced C of G. That is why to go back to GB TR and rubbish military bullets, the slowest possible rifling twist rate (1 turn in 14") was used to reduce bullet spin speeds and hence imbalance caused dispersions. J4s and suchlike are consistent to less that 0.0003", often smaller than that.

This was also how the 'myth' of flat-base designs being 'more accurate' than boat-tails arose. It is much harder to make a super accurate / consistent product with a BT. For years the latter were inferior in their consistency / balance, but people have learned now to make very, very good BT designs these days and that applies to the mass producers too, so Sierra, Hornady, Nosler and Berger etc's products are streets ahead of those of 10 or 15 years ago. Short-range BR doesn't need BT designs and they're too difficult for the smallscale garage workshop producers to make so they remain FB types, but not because FB is inherently superior to BT anymore.

Obviously, other interacting factors / components have to be 'right' too. The best bullet in the world won't shoot well from a poorly made or worn out barrel.

 

[swarovski]

Thanks Laurie.as always a great in depth reply that I imagine answers everybody's questions bar one or 2 more..
Not that anybody does know but you would think a bullet that's not been scarred by the rifling in flight would have a better BC as its way more aerodynamic or does the rifling increases it's BC due to how fast it spins to stabilise the bullet during flight..?

 

[swarovski]

Just thought of another.
Does the rain affect the bullets flight while it's still supersonic or does the rain not come in contact with the bullet until it slows down enough.

 

[User00033]

Now I get the "nut behind the butt" part, for "normal" deer shooting, you're not going to notice the difference between a traditional soft point or an Accubond LR. To those that have discounted the bullet tech and suggested that accuracy is all down to the shooter, I suggest you're missing the point. This thread is in the Interesting Category because if you take the time to read through every post, and pull out the things that you don't fully understand - or are even totally new to you, like Swedish FX barrels were to me - you'll be a bit more knowledgeable than you were before.

I'm a beginner at proper long range (750m+), a novice in every aspect, but take it from this beginner, at 600m (mid range) in gusty conditions, the Hornady .308 178gr ELD-X outperforms the Sierra 180gr Gameking (2160). This out of the same rifle, same shooter, same barrel temps, same everything. I'll track down the photos from a range session a couple of weeks ago and show you the difference in the groups. Less drop, less drift, less spread, tighter group. Period.

 

[ejg]

Laurie thanks for the info.
Back to the melting issue. Hornady has not done themselves any great favours in the micky mouse style clip. No proper facts, no pictures of an actual molten tip and at what speeds it becomes relevant. Only very basic well it gets hot, hotter when flying longer. Not even mentioned if temps are in Fahrenheit or Celsius.
All tips of all manufactures have the same problem??? do they? do they all use the same plastic? There are hundreds if not thousands of plastic compounds possible to make the tips, melting temps range from ~160 C to way over 300 C and just also viscosity varies hugely. Some need huge pressure to be injection moulded around 800-1000bar in liquid form. In shortest time Hornady have found a solution to a problem that I am not even convinced was really there. Why could Hornady not come up with a test bed, or some type of test to prove the theory?
BTW a friend of mine started making bullets years ago and we were discussing the possible in flight temps in the plastic tips and I also suggested a more temp resistent material.
edi

 

[swarovski]

I've watched the hornaday video on the new improved ballistic tips.like edi sez they've not showed us proper hard evidence on this only that using the doplar radar gadget that the new tips improve the ballistics of there bullets.recently I shot some 162gr amaxs at 1000yds and they were really good.if the new tipped ones are better I will move onto them once my stock has gone.hornaday state that there new 7mm 180gr eldm with a incredibly high BC.way more than the 7mm 180gr Berger hybrid.i am looking forward to seeing Brian Litz's testing BC figures.if they are correct then the hornaday bullet should shoot well inside the windrift of the Berger hybrids which still seem to be one of the go too bullets of the f class shooters worldwide so these claims by hornaday maybe a little over estimated.

 

[User00033]

And of course Litz has disproven most - not all - of the Nosler BC claims for the Accubond Long Range. And Litz is primarily retained by Berger, but we will assume he is an honest man.

I imagine a senior management meeting at Hornady, all the propellor heads and marketing suits, gathered around their datasets, glossy mock-ups, Powerpoint presentations, iPhones and iPads on silent....

So, says the engineer, the data says the BCs are this that and the other...
Right, says the marketing suit, that means we can claim x, y, z and more besides, and brand it as follows...
OK, says the salesman, that will translate to so many units of these, so many of those and more of something else...
Good job, says the GM, lets finalise our recommendations to the Executive and go and present in the boardroom.

So off they trundle to the boardroom, where the senior Hornady-David family members are waiting patiently. The presentation goes well. At the end, Steve Hornady stands up, says thanks for your efforts, but its not enough. In order to stay ahead of these pesky Noslers and Bergers, we are going to (a) disclose very little about how any of this works, and (b) exaggerate our technical data to make it look like we are better than everyone else. If VW can do it, so can we.

Silence in the room.

But Steve's the boss, his kids are the VPs and his son in law the Chief Engineer. So what they say goes, right? No one argues. They all trundle out of the boardroom, safe in the knowledge that Steve's got it covered, and they won't get caught out by their customers discovering that none of the BC / drag coefficient data is correct, that its all an exaggerated crock of Mid West BS.

Sound about right? Are we that cynical? Do we, as relatively uninformed consumers, know something these folk don't? Is everything our favourite companies produce these days fake? Marketing spin? Do folk like Steve Hornady or Bob Nosler pin their colours to the Mast of Deception just to make a quick buck? Can they simply get it wrong after so much testing? You can make your own minds up, I don't know, I'm ignorant.

 

[ejg]

there could be a bit of truth in that dodgy.
even so I have a lot of time for hornady ammo and bullets. I live in an area where it is often difficult to get ammo, even 223 or 308. Forget about buying the same type a few weeks later, mostly sold out until next year. Last season I shot all my deer with match ammo and although it didn't expand as violently as say SST the 308 168 BTHP was extremely reliable in accuracy and expansion. I have yet to see a healthy rifle not performing with the Hornady 168bthp. not the best in bc but seems very forgiving just like 155 /168 amax in 30 cal. Laurie explained the reason properly earlier.
edi

 

[swarovski]

Imo the hornaday a max is the best alround bullet I've ever used.i too am sceptical of there claims on very high BC on the bullet I mentioned after asking one of the most knowledgeable shooters.he doesn't think these figures are correct.hopefully Brian Litz will test these bullets shortly and let the whole world know.most of our lives we're treated like mushrooms.kept in the dark and fed sh-t

 

[User00033]

Imo the hornaday a max is the best alround bullet I've ever used.i too am sceptical of there claims on very high BC on the bullet I mentioned after asking one of the most knowledgeable shooters.he doesn't think these figures are correct.hopefully Brian Litz will test these bullets shortly and let the whole world know.most of our lives we're treated like mushrooms.kept in the dark and fed sh-t

Latest score: Cynics 1 : 1 Optimists