Why the tiny hole in match bullet?

K

knowolive2000

Guest
Hi all,

I'm new to serious shooting. I am curious about the purpose of the tiny hollow point in the match bullets (Match King, Scenar, Custom Competition) ? The points seems to be fragile. Aren't they are packed loose in a box? The hole always looks to be dented and out of round. Wouldn't that throw the bullet off track?

The Hornady A-Max match bullets have a nice polymer tip. They would seem to be more resistant to damage.

Opinions anyone?

Thanks.
 
If everyone shot Hornsdy A-Max with those nice pointed ballistic tips in short range benchrest I might win a match or two with my little hollow point bullets.
 
Wow - very cool.

That answers my question. That is very cool !

Thanks.
 
knowolive2000 said:
Hi all,

I'm new to serious shooting. I am curious about the purpose of the tiny hollow point in the match bullets (Match King, Scenar, Custom Competition) ? The points seems to be fragile. Aren't they are packed loose in a box? The hole always looks to be dented and out of round. Wouldn't that throw the bullet off track?

The Hornady A-Max match bullets have a nice polymer tip. They would seem to be more resistant to damage.

Opinions anyone?

Thanks.
Click to expand...

Knowalive, that's a very good question :)

And one best answered by a book! It's hard to answer here.

Here's a VERY incomplete answer.......

The hole is there to get the lead in. The lead is there for the cheap, consistent dense mass it offers. The bullet starts as a little slug of copper which gets hammerformed into a precision cup. Lead is then pressed (swaged) into this cup and the bullet is "pointed up" in a die which closes the hole and holds the lead in. The tip, with it's hole, is called the 'meplat.'

The hole has always bothered people.

Even though it shouldn't!

Suffice it to say that things get a liddle weird at supersonic velocities...... to illustrate this point I've got some VLD (Very Low Drag) projectiles that were modified by a bright guy named Henry Childs. This Engineer took some hyper-slippery long-range bullets, real javelins, and by building fixturing he carefully turned and bored the noses in a lathe. He then fabricated aluminum nose caps and carefully GROUND them to a needle point. These BadBoys are so friggin' SHARP he sent them to me with plastic protectors over the tips.

Here's what Henry tested, before he sent me the leftovers to fiddle with......

He fired these bullets against others through multiple chronographs, an Oehler 43 Ballistics Labratory setup.

SAME BULLET with and without the machined tip and thirdly with the tips CUT BACK to make the hole larger.

UNmodified bullets straight out of the box had the highest BC

Meplat trimmed (tip modified) bullets had most consistent BC and

Tipped bullets had lowered BC and a lessened accuracy potential.

This is one small test but there are books on the subject as well as tools from folks like Whidden and Hoover to trim the meplats back making the hole BIGGER but the bullets perform better.

that said, there are also tools sporadically available for closing up the tips.

it is my unschooled opinion that closing them up beyond a tip diameter of about 50thou is going backwards......

There, that oughtta' get the 'scussion started!

:)

al
 
Back in 1980, the US adopted the M852 National Match cartridge using the Sierra 168 grain MatchKing bullet. This replaced the M118 NM which had been loaded with the FMJ 173 grain bullet. The Army suddenly found itself without a sniper cartridge since snipers had been using the M118, and the hollow point SMK was supposedly prohibited for combat use by the Hague conventions. The Army quickly adopted the M118 SB (Special Ball) which retained the 173 grain FMJ but snipers were very dissapointed with its performance. So, rather than develop a specialized sniper round, the JAG did an end run and proclaimed that the "hollow point" was really an "open point" and the M852 was OK to use in combat. Many field commanders balked at having their snipers carry and use the "open point" cartridges because they were concerned that any sniper who was captured would be shot on the spot. Maybe they were being too cautious but it's a lot easier to sit behind a desk in Washington and say that something is OK, as compared with being in the field and facing a firing squad.

Regardless, the Sierra HP bullets have become acceptable by most nations. The current US sniper/match/tactical cartridge is the M118 LR (Long Range) loaded with the newer Sierra 175 grain MatchKing.

And that's your history lesson for today. Please don't start a discussion about the Hague conventions, hollow point vs open point, etc, etc. These subjects have been beaten to death.

Ray
 
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As I understand it and Francis or Al correct me if I am wrong but, to this point the HP has been proven to be the most accurate bullet style at least in short range BR.
My understanding is that it is because of the balance of the bullet being hollow in the front end.
Thereby making the back end heavier. I dont know that the hole has much to do with the accuracy but I could be wrong.....
 
A perfect base is much more important to accuracy than a perfect tip. Dr. Franklin Mann proved this way back in the beginning of the 20th Century. Many cast bullet shooters use a mould with the sprue cut-off on the nose rather than the base, for the same reason.

If the weight distribution had a lot to do with accuracy, the FMJ bullets with a paper, aluminum, or incendiary point filler would be more accurate than those with a solid core - but they're not.

JMHO

Ray
 
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Back when I read everything shooting I could lay my hands on, I'm sure (sort of, maybe) that somebody - even a lot of somebodies - claimed a hollow point could be finished more reliably & consistently than the alternatives.
 
Vern said:
As I understand it and Francis or Al correct me if I am wrong but, to this point the HP has been proven to be the most accurate bullet style at least in short range BR.
My understanding is that it is because of the balance of the bullet being hollow in the front end.
Thereby making the back end heavier. I dont know that the hole has much to do with the accuracy but I could be wrong.....
Click to expand...

I believe this to be true.
 
I love the tiped bullets and have shot a ton of them,swear by some of them.
i also shoot short range custom hollow points and hunting VLD's so why the hollow points over the sharp sexy tiped bullets.
ever wonder how wind pushes a bullet, it does'ent..bullets turn into the wind..yaw...maybe the hole in the tip helps them to
not turn into the wind,were the sharp streamlined tip turns right into it.just some of my stupid theories, im usually wrong,but sounds good to me.
 
mark-x said:
. . .ever wonder how wind pushes a bullet, it does'ent..bullets turn into the wind...
Click to expand...

Mark

A bullet turns to follow the wind, not turn into it. Or, as some might say, a bullets tail turns into the wind. Same thing, only different, I suppose.

Ray
 
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Im sitting here playing with my new haverkamp action and dreaming about having it finished and shooting. im watching how to shoot beyond belief vidio, and bullets nose into the wind(yaw) into the wind. so the nose of bullet turns in to the wind.
hey i watched the vidio and have one them big dial em in scopes, I was hog hunting with some friends and said watch this i seen this on TV ,I ranged it,dialed my scope,took my wind reading, and held for wind and shot & missed. they just laughed at me and one guy just held off(kuntucky windage i think they call it)and shot and got him.lol so much for that huh. http://www.gunwerks.com/Resources/Long-Range-University/Learning-Articles/Long-Range-Ballistics.aspx
 
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All correctly stabilized bullets turn their nose into the wind, they always try to stay "balanced" on the wind they see. The two winds they see most are the cross-component and the drop-component, one is from the side, one is from the bottom. They HAVE to stay essentially balanced on the wind just like a spinning top on the table or they fall over.... tumble in flight.

It's kindofa' Circle-Of-Life thing. Bullets fired in atmosphere need to be stabilized for accurate repeatable flight and serendipitously atmosphere works well to stabilize a spinning projectile.

Bullets turn their nose into the wind and "follow their tail" in that they're dragged downwind which is the opposite of where their nose is pointing.

al
 
It's deja vu all over again. We've discussed this more times than I can remember.

Go to the Sierra loading manual, page 1065:

4.3 Turning of a bullet to follow a Crosswind and Resulting Deflections

The point was made in Section 3.2 that a crosswind does not "blow" a bullet off course. Rather the bullet turns in the crossrange direction to follow the crosswind. This is a horizontal rotation of the bullet, and, if the bullet is to rotate horizonatlly, there must be a horizontal torque applied to the bullet. A horizontal torque requires a small vertical force be applied to the bullet's center of pressure, and this in turn requires a very small angle of attack of the bullet relative to the velocity vector. . .

What am I missing?

Ray
 
It would seem that just like a weather vane a cone shaped piece of plastic used for a flag would turn point into the wind.
Is this because it is using aerodynamics? Nose first into the wind or pushing the bigger back end out of the way.
 
Ray, the part that's confusing and which has hung up our discussions for so awful long in the past is that the downwind drift isn't actually generated by the wind.

????

:)

And the Sierra stuff is confusing to everybody. SO confusing that they've rewritten it several times. I'm going to try a completely different tack (pun intended)

Bear with me, I'm not very good at this!

First of all, the bullet MUST 'balance' on the wind it feels...... We must believe this.

Let's just take it as flying straight, no wind. The only thing it feels is a huge rushing "headwind"..... and If it turns at all in this headwind it soon tumbles. If it turns at all it "loses it's balance" and gets wind on it's side and tumbles. The bullet is flying into a HUGE headwind, like a 2000 mph headwind because it's going 2000 mph. The only way it can keep flying is to keep its nose centered on this headwind. I'll note for the purists that this 'balance' isn't perfectly "straight" or linear to it's trajectory but that's beside the point, it's BALANCED like a top.

And the bullet is slowing down like crazy.

You add a little bit of crosswind, maybe 10mph. Now this crosswind doesn't actually DO much except try to tip the bullet over, make it tumble. So the bullet must nudge it's nose INTO the new wind to find it's balance. What it FEELS is a small change in it's headwind and it moves to a new balance.

And it's slowing down like crazy.


And here's where so called "wind drift" comes into play.......

It's slowing down like crazy.

In the "no wind" scenario it slows down right in it's own path keeping a straight line.

With a little bit of sidewind IT SLOWS DOWN CROOKED. It's the slowing down, the DRAG, that causes the bullet to move sideways.

The Sierra verbiage keeps pointing out that the balance point isn't perfectly linear to the flight path but WE DON'T REALLY CARE! A round ball acts exactly the same and it aint GOT no point to "fly with a small angle of attack...." that "small angle of attack" just isn't relevant. IMO Sierra gets all hung up on the description of attitude and misses the real point, which is wind drift.

And "wind drift" is caused by the bullet sucking itself offline, under it's own power.

It DOES suck itself!

With a liddle help from the wind just to give it direction.

opinionsby




A'gain :)






al
 
Al

Picture this scenario -

A 3 o'clock wind blowing from the bench out to 100 yards. From 100 to 1000 yards there is no wind. You fire a shot. At the 100 yard target the bullet is 1 MOA to the left due to the crosswind. The bullet is now at a slight horizontal angle due to turning its point into the wind.

The bullet continues on to 1000 yards with its point at the same angle and strikes the target 10 MOA to the left?:confused:

Ray
 
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