Bullet Pointing

[Laurie]

I think setting up the pointing die and checking the diameter is a little more important. If the diameter grows the bullet is junk( core separation)..... jim

Quite agree Jim. I've found though that using the length setting method gives a relatively mild 'point' - certainly my tips are less aggressively pointed that many others I see when I peer into people's open ammo boxes on the ranges.

After over-pointing some 308 155 Lapua Scenars in my first go with the die and which did nothing good to their elevation consistency at long-range, I'm always very keen to do a little less than ideal rather than too much.

Eric Kennard, a forum member who has gained a lot of benefit from pointing the Berger 90gn VLDs he shoots in his 223 Rem uses an optical comparator to judge the optimum amount of effort used. The method he described to me looked very robust and scientific.

In any event, I always reckon it's better to err on the side of caution with this process as it's too easy to damage bullets especially those using the fragile J4 form.

I'll take your measurement checks on board too though - seems a well worthwhile safeguard, and an excellent point (no pun intended!).

 

[johara1]

I have found from 6.5and down pointing works at one 1K. I can not speak for anything larger...... jim

 

[jden]

I remember Ferris Pindell showing us a point closure die he was experimenting with. Cant recommend the point closure procedure one way or the other. Speaking as a point blank competitor using 68 gr. 6mm custom bullets the trimming tool has no noticeable effect for me or my test buddy. As to reducing the metplate size it is our conclusion that a metplate of .060 to .080 for our custom match 60 to 68 gr. is the most accurate and produce smaller agg's. I would advise extra caution closing the point as you may ruin the bullet, Even the custom hand made bullets have varying OAL's and the die setup MUST be dead center to the bullet metplate or its junk. Even a little pressure can cause jacket to lead separation since the jacket walls are very thin. I cringe as to what this would do to a BT.

JDS Bullets
JD Denoff

 

[Steve Blair]

I use a Hoover meplat trimmer and Whidden pointing die. Both work well and have reduced my vertical dispersion and increased B.C. a little. Calibers: 6mm, 7mm, .30.

 

[Erik Cortina]

Dennis, If it makes a difference at 1K it will make a difference at ALL ranges. People are lazy and talk themselves out of doing it,saying they don't see any difference at shorter ranges. I tested at 100 yds. and the ES.and SD. are lower with trimming and pointing and sorting. The Dasher is very easy to see the difference,some others maybe not as easy to see. ES.on the Dasher was 3 and SD.0,and will group in the zeros with a 105H and RL-15......jim

How does trimming and pointing give you better ES?

 

[DennisH]

I would suggest you check with John Hoover at www.accuracyone.com
He can tell you anything you need to know and has all of the quality equipment you need to sort, tip and point.

I called John Hoover and it was worth my time, FYI

How does trimming and pointing give you better ES?

Erik, good question

 

[nosualc]

How does trimming and pointing give you better ES?

+1. Inquiring minds want to know...

-nosualc

 

[LRPV]

I think it's the sorting by bearing surface that helps ES. Not sure how much it helps but some brands and lots can vary quite a bit. I sorted a box of "match" bullets once and had .010" spread from longest to shortest bearing surface.

 

[johara1]

It makes the bullets the same frontal length so ES. is more uniform. and bearing surface is drag, So velocity is more uniform. Annealing also helps with more uniform bullet release. All contributes to better ES....... jim

 

[Erik Cortina]

It makes the bullets the same frontal length so ES. is more uniform. and bearing surface is drag, So velocity is more uniform. Annealing also helps with more uniform bullet release. All contributes to better ES....... jim

I understand annealing and maybe even bearing surface.

But, how does trimming and pointing decrease ES?

 

[johara1]

The different length of the bullets, you seat from the ogive and you trim from the ogive. By making them the same,it decreases the ES when it goes through the chronograph. If you think .010 difference from the meplat to the ogive doesn't make a difference in ES., try it and it sure does make a difference at 1K........ jim

 

[Erik Cortina]

The different length of the bullets, you seat from the ogive and you trim from the ogive. By making them the same,it decreases the ES when it goes through the chronograph. If you think .010 difference from the meplat to the ogive doesn't make a difference in ES., try it and it sure does make a difference at 1K........ jim

The point where you trim and the point where you seat from on the ogive are two different points, how does one influence the other?

 

[johara1]

Yes, they are two different points but it make point to point uniform or the same length. A trimmer indexes off the ogive and seat off the ogive so the length of all the bullets meplat to the ogive is the same. If the length of a bullet is 1.250 and you vary it length of the meplat to ogive by .010 when it passes through the chronograph it will change ES. even if they go through at the same speed, because the distance of the meplat to ogive is only a little over .3 of the total bullet length......jim

 

[Erik Cortina]

So you are saying it makes ES more consistent because if you fire two bullets at the exact same time and speed, the one that is .010" longer will go over the chronograph screens .010" earlier?

 

[Nomad47]

The bullet may get to the first sensor sooner but the time between sensors remains the same.

 

[Erik Cortina]

The bullet may get to the first sensor sooner but the time between sensors remains the same.

You are right bill, that's why I was waiting for his response to really understand what he meant.

I still don't see how bullet trimming and pointing will reduce ES, maybe johara1 can come up with another explanation of how it does it.

 

[memilanuk]

I could see it mattering more @ 1k, like he originally mentioned, as the more similar the bullets are in terms of BC the less divergence you would get i.e. less effect of one slowing down more than another... but I can't see where it would be measurable at the chronograph in front of the muzzle, especially as most of the consumer-grade chronos on the market are not *that* accurate with normal spacing intervals, etc.

 

[johara1]

Tom you are right,what works is what counts. The rest is BS........ jim