Hey guys hope all is well. Question about BC. I live in Nebraska where Hornady is. Been shooting eld match for a while. Recently I have branched out to shooting different ammo to see how my rifle groups. I haven’t shot this federal yet, but curious as to why someone would choose open tip or even the federal 140 gr Berger rounds. They both have a decently lower BC than the Hornady. Without sounding like a rocket scientist, why or in what conditions would a lower bc bullet or an open tip bullet be better? Not trying to say Hornady is better than any other brand just genuinely curious. Thanks!
- Thread starter Bchance5
- Start date
BC matters at distance. Typically 600yds and further. Inside 600yds, velocity plays a larger role.
So, you'd have to take your specific situation into account to decide what matters for you. There are many other factors to consider besides BC, and again, specific to your situation/s.
So, you'd have to take your specific situation into account to decide what matters for you. There are many other factors to consider besides BC, and again, specific to your situation/s.
Run the bc’s and velocities through a ballistic calculator. You’ll see exactly how much it matters.
Maybe not in a bolt action, but I’ve had some issues with the eldm tips breaking off of the bullets and jamming in the locking recess of an AR (Grendel cases). This has caused me to switch to the lower bc, but more reliable feeding, bthp bullets in these rifles.
Hornady almost always exaggerates their bc, that said I like their bullets usually. The 140 eldm trued to .303 g7 for me. Consistency is always king especially past 600y.
BC vs accuracy is a trade off at mid to long range.
Round groups with small verticals is consistency leading to accuracy.
Wide groups due to wind reading error is B.C.
YMMV.
Round groups with small verticals is consistency leading to accuracy.
Wide groups due to wind reading error is B.C.
YMMV.
its not exactly them exaggerating, they just only list the highest BC for the highest mach value on the box...that BC would only apply for the first couple 100 yds of flight or so
the 140 eld's full listed BC values provided by Hornady are .326/.320/.310 for the 3 mach values they test
for most short action cartridges people are shooting, the 3rd mach value occurs around 5-700 yds where you really see BC start to show...which is why most everyone uses a value of closer to .310...600+ yds is where most are tuning up their ballistics to match
printing the highest possible on the box does probably draw more eyes and interest though...they know what theyre up to lol
It isn't hard to imagine at a certain point regarding highest BC, a round is prone to a smaller "happy place". Personally I would prefer a projectile that just shoots without jump sensitivity etc over a few points of BC.
Berger 105 Hybrids come to mind, you just can't get them not to shoot well.....
Berger 105 Hybrids come to mind, you just can't get them not to shoot well.....
It takes pretty big gaps in BC to really make a big difference. Wind deflection maybe grows a little bit, it takes a few more clicks of elevation, but unless you get into a dramatically different trajectory arc shape or push towards being trans-sonic, it's just a different number to dial to. The further you push the target distance out the more you see things creep. Wind reading and rangefinding errors cause bigger and bigger misses, but within 600yd or so with most modern bottleneck cartridges it's about the same story regardless of the bullet used.
A lower BC bullet that shoots tighter is almost always preferable (from a hit probability standpoint) than a higher BC bullet that shoots worse. The best of both worlds is when the higher BC bullet shoots great for you.
There is the argument for BC/drag variability, and what I've seen is that our tipped bullets outperform OTM style bullets pretty much every time. I know there's been a bunch of AB data/FB posts out there saying the opposite-- we haven't observed that and I'm leaving it at that. Regardless, the drag variability really only shows up beyond 800yd in most situations. It takes time/distance for the variable slowing rates to manifest as vertical variation. Certainly important for ELR, but much of the effect is nearly negligible within most "practical" distances and for most targets at something like a PRS match (otherwise certain brands/types of bullets wouldn't maintain a following...). Even in the ELR world, though, you get such a magnitude of external variables that from the end-user perspective drag variability can be muddied up and hard to detect without radar.
Match your performance needs with your application and budget. Use what works best.
A lower BC bullet that shoots tighter is almost always preferable (from a hit probability standpoint) than a higher BC bullet that shoots worse. The best of both worlds is when the higher BC bullet shoots great for you.
There is the argument for BC/drag variability, and what I've seen is that our tipped bullets outperform OTM style bullets pretty much every time. I know there's been a bunch of AB data/FB posts out there saying the opposite-- we haven't observed that and I'm leaving it at that. Regardless, the drag variability really only shows up beyond 800yd in most situations. It takes time/distance for the variable slowing rates to manifest as vertical variation. Certainly important for ELR, but much of the effect is nearly negligible within most "practical" distances and for most targets at something like a PRS match (otherwise certain brands/types of bullets wouldn't maintain a following...). Even in the ELR world, though, you get such a magnitude of external variables that from the end-user perspective drag variability can be muddied up and hard to detect without radar.
Match your performance needs with your application and budget. Use what works best.
Becuase hornady sucks balls and can't make a fucking bullet to save their life.
Their bc consistency sucks which is what really matters. BC can be accounted and calculated. Technically BC consistency can be calculated and translated Into something like WEZ but that won't help you hit a target any better.
It also helps to make a balanced bullet that doesn't blow up due to being spun 300k rpm like most rifle bullets.
That's why people choose a better bullet with a "lower" published BC like berger or Sierra.
Pick up litz books and you won't have to ask dumb questions anymore.
Their bc consistency sucks which is what really matters. BC can be accounted and calculated. Technically BC consistency can be calculated and translated Into something like WEZ but that won't help you hit a target any better.
It also helps to make a balanced bullet that doesn't blow up due to being spun 300k rpm like most rifle bullets.
That's why people choose a better bullet with a "lower" published BC like berger or Sierra.
Pick up litz books and you won't have to ask dumb questions anymore.
I’ll take a consistent BC over a higher BC. Other than Hornady’s ATIPs, which from the 2 boxes of 110s I’ve used I aren’t as consistent in weight and BTO as Berger’s 105s and 109s, they do fly well.
Your best bet is to go shoot them and see what is actually happening with the BC on a waterlined target.
If you want to learn more just ask for resources. I’m sure folks on here would guide you to good articles, books, videos and so on.
Your best bet is to go shoot them and see what is actually happening with the BC on a waterlined target.
If you want to learn more just ask for resources. I’m sure folks on here would guide you to good articles, books, videos and so on.
You seem like a real cool dude, bet you have lots of friends
I agree that ignore is your friend most of the time but sometimes a POS just needs to be a called a POS and after reading numerous post by the ass clown known as DBD. I have to say that’s he’s a POS who seems to enjoy getting on here and being a keyboard commando.
Doesn't necessarily mean that companies exaggerate in BC of their bullets. It's quite possible they just use the optimum accuracy barrels for the cartridge in their tests. BC matters, but consistency also matters. Consistency "equals" accuracy
I'm curious as to what tipped bullets you are using. Not disputing your results, however I have spent a lot of time with one of Litz's books that shows the BC of most modern bullets during different levels of their flight path, and tipped bullets shed their BC a lot faster at the lower mach numbers then the OTM bullets do, which I attributed to the tips deforming due to heat. Yes, even the ELDM's and X's do as well.
I would say that you attributing it to tip deformation is barking up the wrong tree. There are turned copper solids that display the same behavior.
Obviously I've dealt with the ELD line and A-tips mostly. We've shot some competitor bullets on the doppler head. Some are good for aero heating. Some are not.
The way the guys before me found issues with the other tips was by laying multiple tracks with different initial MVs on top of each other and the Cd vs. Mach curves did not line up. Higher initial velocity shots (MV >2900fps or so) had higher drag at common Mach values. Low MV shots (2000-2500fps) had lower drag. The change was from the tip deforming in flight. Shots exposed to the higher velocity and higher levels of aerodynamic heating were softening and deforming more.
ELD does not display that. You can lay the Cd vs. Mach curves on top of each other and they are pretty much a line-to-line fit. We've had bullets launched from 3400+ down to 1800fps and the portions of Cd vs. Mach that overlap lay right on top of each other. The Heat Shield tips may deform slightly but it's orders of magnitude less-- to a point of being negligible to the end user.
So what do you attribute the increased drag to at lower Mach numbers with tipped bullets? ELD's exhibit the same decreased BC as Amax's and other tipped bullets, yet the Bergers and Sierra's with tangent ogives maintain a much more consistent BC throughout their flight path. Is it more a secant ogive nose that is having more difficulty at slower speeds vs hybrids and tangent profiles?
Ogive shape. If you don't have it, you should read "Modern Exterior Ballistics" by McCoy. It's very math heavy, but it's a large part of the foundation that most of what we know and do is built on. I know it's got a section in there with various Ogive shapes/profiles and the respective Cd vs. Mach curves.
Certainly , McCoy's textbook belongs to classics. It resisted time challenge even with 6 DOF considerations of yawing & pitching motion of famous 168 gr. SMK bullet (well..sort of.). I was shocked to learn that subsonic zero-yaw drag coefficient of a M1906 .30 cal. flat base, spitzer 150 gr. bullet is not smaller than subsonic zero-yaw drag coefficient of a typical 9 mm, 124 gr, RN parabellum bullet.
BC is great - it's the factor that more or less represents the ballistic efficiency of any given projectile. The higher the BC, the more efficiently it flies through the air.
But I think consistency is more important. Look at the Nosler RDF's, for example. When they first came out, they had a really high BC for their weight. But when you shot them, they would not group consistency due to inconsistencies from projectile to projectile.
That's why I shoot Berger projectiles whenever I can. In some cases I'm giving up BC, but I'm never giving up consistency.
BC certainly matters, to a point.
But I think consistency is more important. Look at the Nosler RDF's, for example. When they first came out, they had a really high BC for their weight. But when you shot them, they would not group consistency due to inconsistencies from projectile to projectile.
That's why I shoot Berger projectiles whenever I can. In some cases I'm giving up BC, but I'm never giving up consistency.
BC certainly matters, to a point.
At what point in the BC world do we decide between a lighter, faster, lower bc bullet with a two tenth of a second faster time of flight at 1K vs heavier, slower higher BC bullet? Assuming the same consistency using Berger bullets in both applications, when does TOF matter more than just picking the bullet with the highest BC?
I went through this somewhat recently, and made a decision through arbitrary metrics, mostly.
I have a 18" 6.5 Creedmoor barrel for hunting, and was planning on using 140 ELD's for it, but my barrel would only shoot them at ~2400 fps (factory ammo).
Went to 123 scenars, and was easily able to achieve ~2850 fps. An increase of 400+ fps with reloads and a moderate load.
I haven't plotted out the ballistics between these two different loads, but when it comes to terminal ballistics (for hunting), I was concerned with a starting MV of 2400 fps.
So in my case, it was mostly arbitrary. It was what I felt comfortable with, rather than a decision based on pure ballistics and analysis.
Exactly, but 400 fps difference is almost an unfair comparison. I would think you could also handload the 140 ELD hotter than the factory ammo to close the velocity gap.
In doing so, and depending on how far out you plan on taking game, you may see the 140 ELD carries more energy to the target, despite a slower starting velocity, yet spend slightly more time flying to the target. And then your still trying to determine the retained velocity at the target so the bullet does it's job. Kind of makes your head spin.
That's true.
One could do a bunch of testing, see where velocities end up and overlay ballistics charts to see where things land. I hardly did any true analysis.
If I really wanted to, I could try and get 140's, or 130's to work for my applications. But I bought 123 Scenars, really liked how they shot, and that's where testing ended.
The true answer to your question is "it depends". Everything's a trade-off, there is no perfect answer. And honestly, how much of this conversation is purely academic, versus being practical?
True, I tend to over-analyze anything and everything. The more I read, the less I think I know.
It's easy to do.
Just look at PRS - some people are shooting light bullets really fast, others go on the other end, shooting really heavy for caliber bullets slowly.
Both win matches. Both have their pros and cons. But you can be successful across the spectrum of bullet weight and velocities.
In reference to your photos - The only relevant number on the back of a box of ammo is the lot number. Everything else is irrelevant to you and your rifle as a starting place to gather data. Your actual data / drop will reveal your true M/V out to 600. That is, if you know how to true a ballistic solver. Your data / drop at 800 reveals your most usable BC out to 1K and will not be the same as what is on your box.
Your takeaway: Let your actual hits / data / drop be your guide and don't trust published numbers unless they have been confirmed. Box numbers are merely place holders in a ballistic solver until truing.
Always seek to stay within a lot number during purchase.
Always zero at 100 yards.
-Taylor
Your takeaway: Let your actual hits / data / drop be your guide and don't trust published numbers unless they have been confirmed. Box numbers are merely place holders in a ballistic solver until truing.
Always seek to stay within a lot number during purchase.
Always zero at 100 yards.
-Taylor
I'm in the same boat. Specifically how much wind affects the different bullets at slower than "normal" velocities due to running short AR's.
I can calculate drop, but variable winds at "longer" ranges are difficult to determine as everyone seems to get different velocities out of their barrels. Seems the end result might be a pretty fine line.
