The Firing Line Forums

Go Back   The Firing Line Forums > The Conference Center > General Discussion Forum

Reply
 
Thread Tools Search this Thread
Old January 5, 2019, 12:30 PM   #1
M88
Senior Member
 
Join Date: February 15, 2018
Location: Pennsylvania
Posts: 266
Does slightly deformed tip of bullet affect ballistics under 100 yards?



Received a box of Hornady 30 cal 150gr INTERLOCK SP bullets in the mail yesterday. Some of the tips, which are lead, have a few minor dings and a few even have a slight "flat" area on them, presumably from being knocked around in the box during shipping. I don't think that would impact ballistics, but wanted to throw it out here and ask. I'm thinking for closer ranges, like less than 100 yards, no problem. Maybe if I were trying to hit a 400 yard target?
Attached Images
File Type: jpg tip.jpg (55.8 KB, 348 views)
__________________
NRA life member. Making good people helpless doesn't make bad people harmless!
M88 is offline  
Old January 5, 2019, 03:45 PM   #2
Ifishsum
Senior Member
 
Join Date: September 15, 2005
Location: Oregon
Posts: 979
Not in my experience, no. Probably not even at longer ranges either. The bullet base is much more important to be consistent than the tip. I don't think I've ever seen a box of exposed lead points that were all perfect either.
Ifishsum is offline  
Old January 5, 2019, 03:47 PM   #3
NoSecondBest
Senior Member
 
Join Date: December 7, 2009
Location: Western New York
Posts: 2,287
All my Remington .458 404g JHP look like that or worse. They still shoot one ragged hole at 100 yards. I guess my answer is "not that I can tell". If I were shooting benchrest competition I'd probably be more particular.
NoSecondBest is offline  
Old January 5, 2019, 04:39 PM   #4
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 19,550
A guy did a test ages ago, did all kinds of slices, gouges, and drilled holes in the tips of quite a few bullets. No noticeable change to their accuracy.

Holes drilled in the BASE of the bullets, accuracy went to hell.

basically a tiny or small deformation in the tip of the bullet doesn't change the weight or balance enough to matter. In the base of the change of a few grains of weight can destabilize the inflight spin enough to affect accuracy.

Hope this answers your question. The bullet in your pic is normal, and many are much worse with no effect on their accuracy.
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old January 5, 2019, 05:24 PM   #5
Doyle
Senior Member
 
Join Date: June 20, 2007
Location: Starkville, MS
Posts: 6,882
44AMP beat me to it. In the test I saw, the tips would be all banged up with very little decrease in accuracy. Putting a dent in the base caused it to look like a shotgun buckshot pattern.
Doyle is offline  
Old January 6, 2019, 11:54 AM   #6
M88
Senior Member
 
Join Date: February 15, 2018
Location: Pennsylvania
Posts: 266
Quote:
Originally Posted by 44 AMP
...basically a tiny or small deformation in the tip of the bullet doesn't change the weight or balance enough to matter...
THIS is what I suspected, and glad to hear confirmed by those that have experience here. After digging around more since I posted this the other day, I did run into an article that did as 44 AMP said. The guy mangled the tips/front of bullets in all kinds of ways and tested that effect. Little if any change. For ME that is counter intuitive, but lots of things in this world are. Good to know. Thanks folks.
__________________
NRA life member. Making good people helpless doesn't make bad people harmless!
M88 is offline  
Old January 6, 2019, 02:46 PM   #7
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 19,550
Quote:
For ME that is counter intuitive, but lots of things in this world are.
Lots of things in this world are, for me as well. But many things do make sense when looked at in the right way.

First off, with a bullet, it is not only pushing through the air, but also spinning rapidly on its axis. Mass, inertia, torque, and other factors are in play. Bullets are essentially pointed rods thick at the back, thinner at the front. So a tiny change that does actually unbalance the front is over-ridden by the still balanced stability of the more massive rear section.

Anything less than a perfectly balanced nose will "wobble" it's something that could be calculated, math says it must exist, but the effect of that tiny wobble is (usually) hidden /overwhelmed by other factors, so there is seldom any effect on accuracy we can see.

An "unbalanced" bullet base, on the other hand, has a great effect. It is the greatest mass of the bullet, so if the weight is lopsided (not "true" with the spin axis) the bullet won't fly true, either.


Think of a football, as a related example. The point of the ball can wobble a bit but the ball still flies straight enough, if the throwing hand applies the spin correctly to the wide middle of the ball. But, if your fingers slip as you throw, the spin is unbalanced, and the torque of the big part spinning off balance sends the pass to who knows where. The base of the bullet is the "big part" due to its mass.


clear as mud now, right?
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old January 6, 2019, 08:10 PM   #8
M88
Senior Member
 
Join Date: February 15, 2018
Location: Pennsylvania
Posts: 266
Quote:
Originally Posted by 44 AMP
Think of a football, as a related example. The point of the ball can wobble a bit but the ball still flies straight enough, if the throwing hand applies the spin correctly to the wide middle of the ball. But, if your fingers slip as you throw, the spin is unbalanced, and the torque of the big part spinning off balance sends the pass to who knows where. The base of the bullet is the "big part" due to its mass.

clear as mud now, right?
Actually, at least for MY brain, that example did the trick for me and explained it well. Makes sense and thank you!
__________________
NRA life member. Making good people helpless doesn't make bad people harmless!
M88 is offline  
Old January 7, 2019, 08:11 AM   #9
Mike Irwin
Staff
 
Join Date: April 13, 2000
Location: Northern Virginia
Posts: 40,216
"A guy did a test ages ago, did all kinds of slices, gouges, and drilled holes in the tips of quite a few bullets. No noticeable change to their accuracy."

We published that article when I was with American Rifleman back in the early 1990s.

It was quite a revelation to me at the time.
__________________
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza

Baby Jesus cries when the fat redneck doesn't have military-grade firepower.
Mike Irwin is offline  
Old January 7, 2019, 11:03 AM   #10
musher
Senior Member
 
Join Date: April 23, 2005
Posts: 462
No effect
See Rifle Accuracy Facts, Harold R. Vaughn.
musher is offline  
Old January 7, 2019, 05:38 PM   #11
seanc
Senior Member
 
Join Date: December 28, 1998
Posts: 305
These guys are not scientists, but they document what they test and present the outcomes , all in entertaining way:

https://www.theboxotruth.com/the-box...e-box-o-truth/
seanc is offline  
Old January 7, 2019, 05:54 PM   #12
M88
Senior Member
 
Join Date: February 15, 2018
Location: Pennsylvania
Posts: 266
Interesting read seanc... although apparently not professionally done, he took the time to try and get some good results. What he DID show was 44 AMP's assertion that a chunk out of one side of the main MASS of the bullet, like the chunk this guy took from the base with a file, DOES have an effect.
__________________
NRA life member. Making good people helpless doesn't make bad people harmless!
M88 is offline  
Old January 7, 2019, 07:10 PM   #13
Mike Irwin
Staff
 
Join Date: April 13, 2000
Location: Northern Virginia
Posts: 40,216
I think the primary cause of inaccuracy from a damaged bullet base is due to uneven turbulence formed at the base of the bullet.
__________________
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza

Baby Jesus cries when the fat redneck doesn't have military-grade firepower.
Mike Irwin is offline  
Old January 7, 2019, 07:46 PM   #14
M88
Senior Member
 
Join Date: February 15, 2018
Location: Pennsylvania
Posts: 266
Quote:
Originally Posted by Mike Irwin
I think the primary cause of inaccuracy from a damaged bullet base is due to uneven turbulence formed at the base of the bullet.
So Mike are you saying that the turbulence caused from the missing chunk out of the rear of the bullet is more of a destabilizing factor than the fact that the bullet mass is now lopsided, as 44 AMP says "not 'true' with the spin axis"? I would assume it's both. Just out of pure curiosity, wondering what would cause more destabilizing. I suppose that would be determined by how MUCH of the base is deformed.

Also, can I assume that at short range, say 25 or 50 yards, even a damaged base wouldn't matter much?
__________________
NRA life member. Making good people helpless doesn't make bad people harmless!
M88 is offline  
Old January 8, 2019, 04:06 AM   #15
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 19,550
If you take a chunk out of the base of a bullet, so that material is missing from the rim edge of the base you'll get some gas blow by. Maybe gas cutting. And it will be an unbalanced rotation. Worst of both worlds I would think.

You can test this, I think if you notched some bullet bases, and then took others and drilled an equal size hole in the side of the bullet, just above the base, leaving the base intact, you should be able to determine which one had the greater effect on accuracy. If there was any noticeable difference, of course.
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old January 8, 2019, 07:46 AM   #16
Mike Irwin
Staff
 
Join Date: April 13, 2000
Location: Northern Virginia
Posts: 40,216
"So Mike are you saying that the turbulence caused from the missing chunk out of the rear of the bullet is more of a destabilizing factor than the fact that the bullet mass is now lopsided"

That's what I recall from things I've read, because imperfections in the base, even if they don't upset the distribution of the mass of the bullet, can have a significant effect on accuracy.

I know the military did some testing on different methods of closing the base of FMJ bullets and found that uneven closures, lead spurs jutting out through the closure, etc., can really mess with accuracy even if they have very little affect on the bullet's center of mass.

In reality, few production bullets, especially cored ones with drawn jackets, have perfectly balanced centers of mass, or whatever it's called.
__________________
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza

Baby Jesus cries when the fat redneck doesn't have military-grade firepower.
Mike Irwin is offline  
Old January 8, 2019, 11:16 AM   #17
M88
Senior Member
 
Join Date: February 15, 2018
Location: Pennsylvania
Posts: 266
Quote:
Originally Posted by 44 AMP
You can test this, I think if you notched some bullet bases...
Thanks Mike and 44, for humoring my curiosity. To me, ballistics is an interesting subject. On one level, analogous to electronic circuits (I'm a retired electronics tech) in that lots of things happen VERY very quickly. For me the appeal is breaking that instant in time down to human speed to analyse whats happening when. Years ago in my 30's just starting out woodworking I was cavalier with equipment, and as a result suffered stitches and bruised ribs on several occasions from my table saw "shooting" a chunk of wood at me at roughly 80 mph. I've learned to respect equipment and processes the hard way. Segue into re-loading. I'm JUST getting into re-loading, and NOW I tend to be overly cautious on things. Especially things as serious as making bullets where a mistake could cost me a finger. I would LOVE to experiment with loading intentionally defective rounds to test them out. Would be an interesting experiment. Not there yet, but at some point I will be and am going to test this out, just for fun and to satisfy my curiosity.
__________________
NRA life member. Making good people helpless doesn't make bad people harmless!
M88 is offline  
Old January 8, 2019, 08:20 PM   #18
ms6852
Senior Member
 
Join Date: April 3, 2010
Location: Texas
Posts: 1,000
My hunting bullets have always been Remington core-lots. Very seldom will I find a bullet tip to be concentric, but I continue to use them for more than 50 years.
__________________
ONLY TWO DEFINING FORCES HAVE GIVEN UP THEIR LIVES FOR YOU. ONE IS JESUS CHRIST FOR YOUR SOUL AND THE OTHER IS THE AMERICAN SOLDIER FOR YOUR FREEDOM.
ms6852 is offline  
Old January 9, 2019, 02:27 AM   #19
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 6,253
Just an opinion.No science. Along with whatever other problems that may come from a damaged bullet base,
IMO,a damaged bullet base functionally resembles a damaged crown as far as gas .
HiBC is offline  
Old January 9, 2019, 11:28 AM   #20
Skans
Senior Member
 
Join Date: November 20, 2008
Posts: 10,823
Would symmetrically sharpening the tip of a bullet make any difference in long range accuracy? You know, similar to those solid copper bullets which are basically milled from copper wire.
Skans is offline  
Old January 9, 2019, 11:59 AM   #21
44 AMP
Staff
 
Join Date: March 11, 2006
Location: Upper US
Posts: 19,550
Quote:
Would symmetrically sharpening the tip of a bullet make any difference in long range accuracy?
I don't know, but my guess would be "not enough to matter". Look at the long range match bullets today, all are very, very pointed, but none comes to a needle sharp tip.

I would also think that if you "sharpened" the bullet enough to change the BC that would make a difference in long distance flight, though perhaps not in the accuracy (group size) necessarily.
__________________
All else being equal (and it almost never is) bigger bullets tend to work better.
44 AMP is offline  
Old January 9, 2019, 01:41 PM   #22
M88
Senior Member
 
Join Date: February 15, 2018
Location: Pennsylvania
Posts: 266
Quote:
Originally Posted by 44 AMP
I would also think that if you "sharpened" the bullet enough to change the BC that would make a difference in long distance flight...
An interesting test of this would not be that difficult to do. Heck even I could do it. All the known data and facts seem to point to the assumption that it would make no difference, but would be interesting to try anyway. Sharpening 5 or 10 bullet points in my shop to exact needle points would only take a few minutes on the metal lathe. The bottom line however, is I would think that if a needle point sharpened bullet would indeed make a difference, the long range match shooters would already be doing it. Thus... a moot point.
__________________
NRA life member. Making good people helpless doesn't make bad people harmless!
M88 is offline  
Old January 9, 2019, 02:16 PM   #23
Roadkill2228
Senior Member
 
Join Date: March 8, 2014
Location: Nipawin, Saskatchewan
Posts: 296
At ordinary distance it makes no difference. One of the 2 most accurate billets tried in my old savage 99 243 is the Speer 100 grain boat tail soft point (not the hot cor). It’s a very soft bullet, some of them look “smeared” like the exposed lead got roughed up and the tip is visibly shoved to the side. Still accurate. As distance grows, this would definitely be a problem. Blowing up milk jugs out to 300 yards, no discernable effect. As had been said, the base is more important if not concentric. All 1000 yard records have been made with boat tails, and pretty much all 100 yard records are made with flat base bullets. At distance the aerodynamic efficiency of the boat tail becomes more important than the greater inherent accuracy of flat base bullets. A flat base is less sensitive to imperfections in the crown of the muzzle, a worn throat, rough rifling, seating depth, pretty much everything. It’s not that they fly better, they don’t, it’s that less can go wrong with them.
Roadkill2228 is offline  
Old January 9, 2019, 02:21 PM   #24
briandg
Senior Member
 
Join Date: May 4, 2010
Posts: 5,308
Quote:
First off, with a bullet, it is not only pushing through the air, but also spinning rapidly on its axis. Mass, inertia, torque, and other factors are in play. Bullets are essentially pointed rods thick at the back, thinner at the front. So a tiny change that does actually unbalance the front is over-ridden by the still balanced stability of the more massive rear section.

Anything less than a perfectly balanced nose will "wobble" it's something that could be calculated, math says it must exist, but the effect of that tiny wobble is (usually) hidden /overwhelmed by other factors, so there is seldom any effect on accuracy we can see.

An "unbalanced" bullet base, on the other hand, has a great effect. It is the greatest mass of the bullet, so if the weight is lopsided (not "true" with the spin axis) the bullet won't fly true, either.

This is all correct.

Two things to consider, or so...

That slightly deformed tip actually takes only the tiniest bit of material and puts it off balance, right there at the axis of rotation. With the spin of that massive bullet, the thing is going to be stabilized based on all the rest of the lead. That little bit of skewed weight at the end of the axis can't possibly upset the stability of the rest of that mass. Not that it would really matter, as shown by the football, even if the nose started to rotate the body (center of the mass) would still remain stable (in relation to itself) in space without being affected.

While some people would think that friction would affect the bullet adversely, that air would push it aside, much like the spoiler on a car, once again, we have so little deviation that could be caused by the friction that it wouldn't be able to push the bullet off of axis. Again, pushing it off of axis would not result in the bullet taking another path, it would just cause the bullet to "wobble". Since it is also rotating, it also has to be pointed out that if the pressure or imbalance is on the 'outside' of the rotation, it's going to just guide that deviation back to center. Unless the damage causes deviation outward from the axis, there won't even be a reason for the thing to destabilize from the axis, it will self correct.

As was said, it has been tested, and casual testing showed no deviations. If you set up scientific conditions and tested it in the most extreme distances, there still may not be any deviation that would show when compared to bullets with perfect points.

As we have read, yes, damaging the base where the mass is located can cause the bullet to have problems. First, a chunk of missing base material causes the bullet to leave the bore with a 'poof' on one side, causing a tiny bit of instability. Friction at outer edge of the base can cause the heavier base to destabilize a bit. with both wind drag and a weight being off center of the axis, any deviation at the edge and towards the center of the mass will be more inclined to push the axis off.

Look at someone whacking a golf ball. See how the dimples make them go on wide, arching flights? The dimples on the bottom are resisting the air that they are flying into. The dimples at the top are not having to resist that pressure. The dimples at the bottom actually function like a wedge, or ramp, as the dimples are forced through the air, pressure against the dimples on the bottom push on the center axis of the ball. This will cause the ball to climb if the ball is rotating backwards.

Regardless of what direction the ball is actually flying, it will follow a straight (mostly) line perpendicular to the rotating access, just like a gyroscope.

Let me be the first to assure you that whacking a bullet with a golf club isn't going to answer any questions. It will just waste a lot of bullets.
__________________
None.
briandg is offline  
Old January 9, 2019, 04:52 PM   #25
WanderingSol07
Junior Member
 
Join Date: November 13, 2018
Posts: 6
If I remember correctly, handgun rounds spin 70,000 to 90,000 rpm. Rifle rounds are 200,000 to 250,000 rpm. But for the distance being mentioned, not very far to affect accuracy. Now for an out of balance bullet at 1,000 yards, I'll bet it is buzzing and tumbling by then.
WanderingSol07 is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 06:16 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.09071 seconds with 9 queries