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Long Distance Shooting Discuss tools, techniques, tips and theories of long distance shooting

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  #1  
Old 12-04-2017, 1:55 PM
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Default Basic question: why are Sierra match kings hollow points?

I have wondered why they are made in hollow point configuration, as they arenít designed to expand, and arenít recommended for hunting?

Why not a more aerodynamic pointy end for a match bullet?
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  #2  
Old 12-04-2017, 2:42 PM
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From my little homework on the subject creates a gap of air in front for better flight.
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Old 12-04-2017, 4:15 PM
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Match Kings are ballistic hollow points formed around around a piece of lead matching the profile of the completed bullet.A bullet for competition purpose is very thin ,like foil for this reason it would not be a good choice for large game.
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Old 12-04-2017, 4:15 PM
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Originally Posted by jeremyy View Post
From my little homework on the subject creates a gap of air in front for better flight.
Yeah No.... that's someones BS theory

The hollow point is purely a product of the manufacturing process. As it is far easier to cup a jacket blank with a full caliber base diameter than it is to try a swage a core and jacket down to a perfect point. Also Jacket wall thickness is more easily controlled and this increases bullet stability due to being closer to perfect balance.

Try to make the bullet the other way and you lose your ability to control wall thickness and concentricity.

FMJ's have very thick jacket walls but are very poor in uniformity.
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Old 12-04-2017, 4:18 PM
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Quote:
Originally Posted by kcstott View Post
Yeah No.... that's someones BS theory

The hollow point is purely a product of the manufacturing process. As it is far easier to cup a jacket blank with a full caliber base diameter than it is to try a swage a core and jacket down to a perfect point. Also Jacket wall thickness is more easily controlled and this increases bullet stability due to being closer to perfect balance.

Try to make the bullet the other way and you lose your ability to control wall thickness and concentricity.

FMJ's have very thick jacket walls but are very poor in uniformity.
The internet doesn't lie!!! Lol
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  #6  
Old 12-04-2017, 4:18 PM
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Originally Posted by highpower790 View Post
Match Kings are ballistic hollow points formed around around a piece of lead matching the profile of the completed bullet.A bullet for competition purpose is very thin ,like foil for this reason it would not be a good choice for large game.
And not true as well

While that may be true for Sierra is is not true for Berger. Berger VLD's are thicker jacketed than their Hunting bullets. And that is all due to their manufacturing process. they can control jacket thickness even with a thicker jacket than their hunting round. Thicker than Sierra?? that I don't know.
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Old 12-04-2017, 4:25 PM
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Quote:
Originally Posted by jeremyy View Post
The internet doesn't lie!!! Lol
Well the internet doesn't lie. It merely repeats the information others post. It's up to the end user to discern if that information is true.

There is a minor low pressure zone just behind or sometime on the the ogive of the bullet. The air pressure at the tip is high pressure. The only air gap is the eddy current just behind the bullet, and the boat tail helps the transition for smooth stable flight.
Basic aerodynamics.

I recommend a book
The bullets flight from powder to target By Franklin Weston Mann late 1800's Ballistician Very crude science but it's the point of discovery of the why and hows of basic bullet flight.

Last edited by kcstott; 12-04-2017 at 4:28 PM..
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  #8  
Old 12-04-2017, 6:15 PM
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To be fair they now have tipped matchkings.
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  #9  
Old 12-04-2017, 7:10 PM
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I have read (not on the internet) that the projectile base is one of the most important factors in the incipient phase of external ballistics-as the bullet leaves the muzzle. A uniform base ensures even gas pressures at the juncture of the muzzle to maintain stability. kcstott alludes to uniformity in mfg, and since the base is formed from the cup, the ogive is just closing the jacket.
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Old 12-04-2017, 8:56 PM
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The tip or meplat is left open because it would require additional steps to close it up.
The lead core gets forced into the jacket so the ejector pin needs to be strong enough that it doesn't bend or break. This is what gives you the hole in the bullets meplat.
Most major manufacturers try to keep the hollow point at or above 12-15 % of bullet diameter.
So a 30 caliber bullet will have a meplat around 0.045 in diameter while a 22 caliber bullet will be around 0.030 in diameter.
You can close the tip using a tipping die but you need to sort your bullets first. If you don't sort them you will end up with multiple length bullets and while your ballistic coefficient will be improved the variation won't.
Typical hollow point match bullets can have a BC variation as high as 0.020.
By sorting then trimming and tipping you can increase the bullets BC number and remove most of the variation bullet to bullet.
If you start two bullets at 3000 FPS and one of them has a 0.500 BC and the other has a 0.520 BC you get 8 inches of vertical variation at 1000 yards.
As most 5 shot records at 1000 yards are sub 2 inches you can't have much BC variation if you want to be competitive.
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  #11  
Old 12-04-2017, 9:28 PM
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Quote:
Originally Posted by LynnJr View Post
Typical hollow point match bullets can have a BC variation as high as 0.020.

If you start two bullets at 3000 FPS and one of them has a 0.500 BC and the other has a 0.520 BC you get 8 inches of vertical variation at 1000 yards.
Wow, that's eye-opening.
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  #12  
Old 12-04-2017, 10:01 PM
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US Team Coach Larry Bartholome and Dr Oehler the chronograph guy had the BC variation posted somewhere but I can't remember where I read it anymore.
Most likely Benchrest Central.
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  #13  
Old 12-05-2017, 10:19 AM
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Quote:
Originally Posted by LynnJr View Post
The tip or meplat is left open because it would require additional steps to close it up.
The lead core gets forced into the jacket so the ejector pin needs to be strong enough that it doesn't bend or break. This is what gives you the hole in the bullets meplat.
Most major manufacturers try to keep the hollow point at or above 12-15 % of bullet diameter.
So a 30 caliber bullet will have a meplat around 0.045 in diameter while a 22 caliber bullet will be around 0.030 in diameter.
You can close the tip using a tipping die but you need to sort your bullets first. If you don't sort them you will end up with multiple length bullets and while your ballistic coefficient will be improved the variation won't.
Typical hollow point match bullets can have a BC variation as high as 0.020.
By sorting then trimming and tipping you can increase the bullets BC number and remove most of the variation bullet to bullet.
If you start two bullets at 3000 FPS and one of them has a 0.500 BC and the other has a 0.520 BC you get 8 inches of vertical variation at 1000 yards.
As most 5 shot records at 1000 yards are sub 2 inches you can't have much BC variation if you want to be competitive.
Ok I’ll bight
Sorted how, weight, length, bearing surface??

Just got a new batch of 500 SMK’s that I want to tip

Last edited by kcstott; 12-05-2017 at 10:23 AM..
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  #14  
Old 12-05-2017, 11:02 AM
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Quote:
Originally Posted by kcstott View Post
Ok Iíll bight
Sorted how, weight, length, bearing surface??

Just got a new batch of 500 SMKís that I want to tip
Please post photos of the process...
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  #15  
Old 12-05-2017, 11:06 AM
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Originally Posted by kcstott View Post
Thicker than Sierra?? that I don't know.
When I started reloading and shooting XTC, I used to hear from the old timers that the Sierra jacket is thick or thicker (compared to what, don't know) since Sierra bullets like to jump.

Now, whether Berger jacket is thicker than Sierra, don't know about that but I do know that I've never had a bad ammo from using either brand
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  #16  
Old 12-05-2017, 2:41 PM
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That design imperative is also a reason premium hunting bullets can be so dang accurate. I used up a bunch of expensive lead bullets punching paper due to the non-lead hunting laws and saw great accuracy results in many cases. The corollary to that is the Barnes copper bullets are consistently VERY accurate.

The base of the bullet is SUPER important, and why even the boat tail FMJ's for 5.56/223 have mediocre accuracy even when carefully handloaded.
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  #17  
Old 12-05-2017, 2:48 PM
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Quote:
Originally Posted by Citadelgrad87 View Post
Please post photos of the process...
Here's a pretty good video of the process:
https://www.youtube.com/watch?v=C2FBlnP2u1M
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  #18  
Old 12-05-2017, 5:32 PM
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Taken from the Berger Bullets website:
http://www.bergerbullets.com/change-...target-bullet/

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Old 12-16-2017, 2:14 AM
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Quote:
Originally Posted by kcstott View Post
Ok Iíll bight
Sorted how, weight, length, bearing surface??

Just got a new batch of 500 SMKís that I want to tip

When your tipping bullets they need to be trimmed. If the length varies bullet to bullet when you trim them the diameter at the trim point will vary so the tipping process will increase the bullets BC but the variation will still be there.
Sort them by bearing surface first then longest length next from like batches.
Then trim.
Then measure the diameters in a gage block.
Then tip and remeasure with the gage block.
You work long to short so you don't bulge any part of the bullet
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  #20  
Old 12-16-2017, 5:38 AM
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Quote:
Originally Posted by LynnJr View Post
When your tipping bullets they need to be trimmed. If the length varies bullet to bullet when you trim them the diameter at the trim point will vary so the tipping process will increase the bullets BC but the variation will still be there.
Sort them by bearing surface first then longest length next from like batches.
Then trim.
Then measure the diameters in a gage block.
Then tip and remeasure with the gage block.
You work long to short so you don't bulge any part of the bullet
Thanks Lynn This is going in my notes
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  #21  
Old 12-16-2017, 7:52 AM
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I concur with the comment about Barnes bullet accuracy. I’ve seen significant differences between factory jacketed lead and the Barnes all-copper bullets. Made me look like a good shot.
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