Why is there a market for bullet pointing?

[Bryan Litz Ballistics]

Jefferson,

I haven't directly tested the 185 LRBT (Juggernaut) for BC increase from pointing. But based on the geometry of that bullet, I would expect a modest increase in BC, on the order of 3%.

-Bryan

 

[Keith Glasscock]

Bryan, are your pointing tests done the same as your other BC tests (microphone array)?

I have some data from shooting intermingled pointed and unpointed 200 hybrids in my F/TR rifle that suggests a 3% improvement in BC (~5" higher point of impact for the 10 that were pointed vs the 10 that were not).

 

[Bryan Litz Ballistics]

Yes,

When testing pointed bullets, I always test them back-to-back with unpointed bullets of the same lot in order to really identify the difference made by pointing.

Observing difference in BC from drop is difficult to do with great resolution due to group and MV dispersion, etc, but 3% sounds very reasonable for that bullet.

-Bryan

 

[watercam]

Now I see why I am not seeing more of a benefit from pointing my Berger Fullbores! May as well keep it up anyway, one does catch the odd extra long or short bullet occasionally.
Bryan and Company thank you for being involved to this degree!

 

[dreever]

One should consider at what yardages you intend to shoot to determine if the investment in a pointing die and meplat trimmer would benefit the initial $$$ outlay. In my own testing at yardages below 500 meters I could not find any significant benefit to speak of. In testing at 800 yards the benefits became a bit more apparent especially in the elevation clicks required to get on target. This in itself proves there can be a BC advantage to pointing for the long range shooter.
Just my own observations so please take it with a grain of salt.

Danny

 

[Rtheurer]

Im with you Danny. In testing pointed bullets, I have found that for my application 600yds and under I don't bother. 800 to 1000 yards I saw the more significant advantage.
Hope all is well.
Russ T

 

[KWeigel]

This is a great thread! Love the input.

 

[Diver160651]

Thanks for the data!

I'm sure it is not needed to mention this to those that already point, but a very important step is to sort from ogive to base first, then trim and point for consistence performance. Sorting is as important as the pointing part of the process. So what your really getting when you point are sorted and pointed bullets.

For me, consistency is the only reason I point some bullets and the need to sort or sort and point for ELR shooting varies by mfg. Some you want to sort and point others you don't need to and some you can not. For example:

- 7mm/.284 VLD Bergers - The sorting only seems to ween out a few and the tips so consistent, that I do not point them.

- .300 SMK (my barrel prefers them over other MFGs) swings of base to ogive and overall length and weight. Sorting and pointing seems to make tighter the groups at Transonic and Subsonic ranges (so much going on that it can be in my head).

- 338 Turned solids that are very consistent, but a bear for several reasons, Lap and berger are fairly consistent, but two of my my barrels seem to transition A-max the best. However, they are incredibly inconsistent. Measure length or weigh box to box in the same lot and you think your calipers and scale are a mess. You can't trim and point plastic tipped bullets, so sorting base to ogive seems to be the best solution, then by weight.

The BC improvement for bullet pointing depends on the bullet. In general, you'll see between 3-6% improvement in BC, rarely as much as 8% or 10%.

Basically, the larger the meplat starts out, the more gain you get from pointing.

Here are some results of live fire measurements:

Berger .224 cal 77 gr BT: 1.8% improvement

Berger .243 cal 115 VLD: 5.5% improvement

Hoover .264 cal 136 gr: 2.4% improvement

Berger .284 cal 180 Hybrid: 9% improvement (larger than average meplat diameter on this bullet)

Berger .284 cal 168 and 180 VLD: 1% to 2% (see end of this article: http://www.appliedballisticsllc.com/Articles/ABDOC109_1_7mmPart1.pdf

Berger .308 cal 155 gr BT: 1% improvement

Berger .308 cal 155 gr VLD: 3.8% improvement

Note that all of the above data is from live fire measurements of BC.

Also note that the % improvement depends greatly on meplat diameter, and that's something that can change with bullet lots. You might see 6% improvement on a lot having larger than average tips, but then only 2% improvement in the next lot which come out of the box pointier.

The added complexity and cost of pointing bullets at the factory is the biggest reason it's not done for all bullets. It's hard to justify making your product more expensive for everyone to achieve such a small gain which only a few people would notice. That's why aftermarket pointers are good tools; those who care that much about it can do it if they prefer.

-Bryan

 

[Joe Grad]

Brian,

I used the regression equation in your book to get this chart. My results don't seem to be consistent with what you're showing. Does this graph look incorrect???

 

[Joe Grad]

What is the smallest meplat one might expect to get by pointing a 180 grain hybrid?

 

[Joe Grad]

Again using the Litz regression...

 

[JAnderson94]

If there is a 3% increase in B.C., lets say the bullets all have an even .5 G1 B.C. When you times your .5 by 3% you get 0.015, does this mean your increasing the bullets G1 B.C. to .515, or is my math wrong?

 

[Alpine]

I'm wondering if the new pointed 142-gr SMK has been tested? I'm seeing approximatly 0.1-mil less drop between 1100 and 1350 yards over the legacy SMK's in my 260 Rem. I'm using the AB program in my Kestral using a G7 BC of .301 which corresponds accurately with the non-pointed 142's. If I increase that to .303, it corresponds to what I'm seeing with the pointed bullet. However, I called Sierra, asking if they had a BC figure established for the pointed 142's, and they gave me a G1 BC of .626 which in my mind is not realistic. Sierra probably meassured that BC well over 2800-fps?

 

[Alpine]

Set the G7 BC to .305 in my AB Kestrel for the pointed 142-SMK's, and took it out to 1100 yards, And it tracked perfectly. At 1200 yards I was still a little off.

 

[DocBII]

Good day,

Just bought some old bullets from well-regarded manufacturer and now I remember why I trim and point. The progress modern bullet manufacturing has attained in the past 10-15 years is amazing. These actions are hardly needed when the manufacturer decides consistency is a good thing, but still add to removing the last little bit of vertical from your groups.

JMHO,
DocBII

 

[JHardy]

Cat:

Well said. You shot a center X pinwheel.

Jim Hardy