Meplat trimming versus trimming and pointing after sorting bullets

[Dave Way]

I'm thinking about the following and would appreciate your opinions. I am considering sorting bullets first by bullet base to ogive then with a Bob Green tool to verify the nose geometry. At that point I suppose some would consider trimming and pointing since the nose lengths could now be uniformed off the sorted ogive sets.

I have a pointing die but to be honest I have always worried about damaging a bullet with a pointing die. My reasoning is this, and please correct me if I'm wrong, in the normal pointing process the die is in full contact with the jacket and that jacket is pressing against the lead core as the bullet is pointed up. With a tipping die, it seems that the die only contacts the very tip of the bullet and the rest of the jacket is unsupported. Improper adjustment, and I doubt it would take much, seems like it could damage the original ogive or in a severe case, possibly cause separation of the jacket and core. Maybe I worry too much but these are Vapor Trails and they are not easy to come by. Yes I know, they probably don't need much sorting anyway.

For the reasons above, I am considering only meplat trimming to uniform BC's of the sorted ogive sets and not pointing. I realize BC's will suffer somewhat if I don't point, but it should be minimal. The meplats look pretty good as is so I will be removing minimal material to uniform them.

I should mention that I intend to shoot these in 1,000 yard benchrest competition.

Curious to hear your thoughts.

Thanks-Dave.

 

[Sniper338]

To 600 yards you wont notice a difference. Out to 1000 ita help if trimed and pointed. Its not about omproving BC, its about unfiorming BC

 

[Ned Ludd]

If you decide to point your bullets, sort them with Bob's tool after pointing, not before.

The whole idea of pointing is to gain a slight improvement in BC, and therefore, resistance to wind deflection. It works. However, the improvement is generally small, maybe 3-7% increase in BC depending on the ratio of meplat diameter to bullet diameter. I can see a decrease in drop of 0.125 to 0.250 MOA (one to two clicks) with pointed versus unpointed bullets at a distance of only 300 yd. If you can see a decrease in drop, by definition you have increased the BC, and therefore will also enjoy a small decrease in wind deflection.

The question of what is or isn't worth the effort is one only you can answer. My suggestion would be to prepare bullets using each of your proposed steps, generating a group of bullets that represent each individual step from start to finish. Then load them identically (charge weight, seating depth, etc.) and shoot groups with each at 300+ yd. That should give you a much better idea of what each individual step will (or won't) do for you at the target, and should make the decision of what step(s) to pursue a little easier.

 

[F Class John]

FWIW I trimmed and pointed for a while last year. I used a Giraud meplat trimmer and a Hoover pointer. For me it just wasn’t worth doing both so I stopped trimming. Maybe I’m an idiot or incapable of trimming correctly but I found that my confidence in my loads fell off considerably when I was doing both plus it adds that much more time to each round I load. In my case it opened up more variables that I felt I could reasonably control and my scores suffered as a result so I removed that step. Now I only point but even that is something I’m starting to question now that I’m shooting load development on the new 184 hybrids. Their points are far better and more closed up than the 180’s were so I’m not sure what will happen there. Take it for what it’s worth, I’m just one opinion and that doesn’t make me the right one.

 

[watercam]

Like an idiot I pointed some bullets without trimming (years ago mind you) and went straight to a Regional LR Championship match of some four days and about 350 rounds. The bullets that made it to the target were great. The one's that blew up (about 10%) did not make my day(s). It is very possible to damage the core/jacket interface if over done.
I have dabbled in trimming and pointing several times over the intervening years and frankly came to the conclusion that it is easier to pay closer attention to the wind - especially with sling and iron sights at 1000 yds..

 

[rkittine]

I bought all the pits and pieces to do this after seeing it in action at the Williamsport 1000 yard Bench Rest School. So now I have a King Comparator to sort by Baring surface rather than base to ogive and the metplat trimmer and tipping dies, but I have also purchased some of Sierra's Pointed projectiles and I have to determine where to put the emphasis.

Bob

 

[Jet]

Some bullets respond well to pointing and others do not. It's hard to give a definitive "do it" or "don't do it" since the amount someone points is under their control.

Recommend this be part of your load development process. Compare results and make decisions based on what the target tells you.

Good Shooting.

Rich

 

[SGK]

Applied Ballistics' Modern Advancements in Long Range Shooting Vol II has a section worth reading in this regard.

 

[rkittine]

I have been told to not do it to Berger bullets due to the thinness of their jackets, or if I do try it to be extra careful.

 

[dkhunt14]

FWIW I trimmed and pointed for a while last year. I used a Giraud meplat trimmer and a Hoover pointer. For me it just wasn’t worth doing both so I stopped trimming. Maybe I’m an idiot or incapable of trimming correctly but I found that my confidence in my loads fell off considerably when I was doing both plus it adds that much more time to each round I load. In my case it opened up more variables that I felt I could reasonably control and my scores suffered as a result so I removed that step. Now I only point but even that is something I’m starting to question now that I’m shooting load development on the new 184 hybrids. Their points are far better and more closed up than the 180’s were so I’m not sure what will happen there. Take it for what it’s worth, I’m just one opinion and that doesn’t make me the right one.

I believe if you noticed a lower score, you overpointed them. I measure bearing and point, then I measure bearing again, if it changed you distorted the bullets. I don't trim but I pick out same overall length after batching by bearing. Matt

 

[dmoran]

If you decide to point your bullets, sort them with Bob's tool after pointing, not before.
The whole idea of pointing is to gain a slight improvement in BC, and therefore, resistance to wind deflection......

Who says pointing is all about gaining BC?
It's not why I and many others do it. For me, it is for BC consistency and bullet uniformity, just as the OP desires.

I also 100% disagree with not sorting with Bob's tool until after pointing. It is an ogive qualification step, that results in more uniform segregation's. And is exactly why it should be done prior to trimming/pointing as well.

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@twp416

Your proposed process' and reasoning's are all good IMO.
Will warn to not over point (which can cause bullet deformation) as well as advice to trim minimally/sparingly.
Also with advice to accuracy test the amounts.
Good Luck

 

[F Class John]

I believe if you noticed a lower score, you overpointed them. I measure bearing and point, then I measure bearing again, if it changed you distorted the bullets. I don't have trim but I pick out same overall length after batching by bearing. Matt

It wasn’t overpointing for me in the normal sense. It was inconsistent meplat trimming which then in turn led to time costly pointing procedures that probably in some cases over pointed because of the procedure I was using to sort them. Between erratic trimming and erratic pointing it just wasn’t worth it for me. Could I make it work, sure but it isn’t worth my time or frustration. I feel more confident in my loads simply pointing now. That’s all. To each their own.

 

[Laurie]

Who says pointing it's all about gaining BC?
It's not why I and many others do it. For us, it is for BC consistency and bullet uniformity, just as the OP desires.

In fact, one of the striking things in comparing Litz's 'Form Factor' and G7 average BC values for factory pointed Sierra MKs and their unpointed originals in Ballistic Performance of Rifle Bullets 3rd edition is how little difference pointing makes. If there is a significant average BC difference between pointed and original forms it is invariably because Sierra also changed the bullet shape, usually with a longer radius nose.

This flies a bit against actual on-paper results in that pointed bullets usually need a little less long-range elevation. However, like Donovan, it's the improvements in elevation consistency that makes it worthwhile IMHO.

Some bullets respond well to pointing and others do not. It's hard to give a definitive "do it" or "don't do it" since the amount someone points is under their control.

My conclusions too. I found it (trimming and pointing) well worthwhile with older and very inconsistent 7mm 175 and 180gn SMKs and even with the very well and consistently made 180 Lapua Scenar-L, but stopped doing it with most 224 and 308 Bergers. Others swear on improvements to the heavier 224s through doing this though, so it's what works for you and your loadings.

 

[Ned Ludd]

Who says pointing it's all about gaining BC?
It's not why I and many others do it. For me, it is for BC consistency and bullet uniformity, just as the OP desires.

Improving the consistency of the meplat is one of the reasons the BC goes up, don't you think? Consistency, uniformity, increased BC...I can't remember to list every single possible reason for pointing bullets every time this topic comes up, which is relatively often. I wasn't deliberately trying to overlook any of them.

On another note, anyone that owns a LabRadar can easily use it to measure the potential effect(s) of any bullet modifications they may wish to try. In my hands, BCs derived from velocity drops over distance from plugging the LabRadar data into JBM Ballistics [http://www.jbmballistics.com/cgi-bin/jbmbcv-5.1.cgi] have been very good with respect to box BC values and predicted BC increases from pointing. So it's not that difficult to actually quantify the change in BC if you or a friend owns a LabRadar. Other potential benefits from pointing such as improved consistency/uniformity can be evaluated concurrently from group data/targets.

 

[mikecr]

Improving the consistency of the meplat is one of the reasons the BC goes up, don't you think? Consistency, uniformity, increased BC..

Maybe I'm somehow reading it out of context, but this statement in itself fails tests.
You could trim meplats, opening them to a consistent & uniform diameter.
This WOULD NOT increase BC.

Even closing of meplats can reach a point of diminished return (drag-wise)(below ~20thou), and according to McCoy there is a point where drag goes back up a tad(from prior gains)(below ~10thou). That is, there is little reason to close below 20thou, and even less to go below 10thou.

I believe the meplat offers a potentially beneficial aerospike affect.
And as we close the meplat, it's affect on drag decreases. Therefore, it's contribution to drag variance decreases.
That's a good thing.

Opening meplats to a consistent diameter is not as easy as it seems. This, because trimming tools are merely taking noses to same length rather than trimming meplats to same diameter. So with this, trimming can increase both drag and drag variance.
We need the genius behind KM's indicated primer seater design -to solve that one.
Until then, we have pointing.

 

[savagedasher]

Paper or a crony set up at long range is the only way of testing I know of

 

[Dave Way]

Thanks everyone for taking the time to respond. I'm waiting for a couple measuring tools to arrive and when they do, I'm going to go ahead and sort all 2,000 by bullet base to ogive. Then I'll sort those lots with Bob Green's tool to verify nose geometry. For the next step, I'll probably wait till spring before meplat trimming any to see if I can record any difference made by trimming only, then the same testing may be carried out for trimming and pointing.

Of course there is the Bullet Genie out there which is supposed to put an end to all this sorting. Anyone care to share their experience with one???

It uses eddy currents to analyze the bullet.

https://bulletgenie.com/


Dave.

 

[rwj]

Of course there is the Bullet Genie out there which is supposed to put an end to all this sorting. Anyone care to share their experience with one???

What’s the principle of operation?

 

[rardoin]

Paper or a crony set up at long range is the only way of testing I know of

Labradar on the firing line and e-target downrange would give great information on velocity decay.

 

[memilanuk]

What’s the principle of operation?

I think it's supposed to be a modern version of the Juenke machine? Not sure...