Metplat Trimming - Bullet pointing

T

Trhodes

Guest
I'm probably covering an old question but the 'search' function on this site produced zip.

Do you go through metplat (meplat) trimming and/or bullet pointing on your F T/R rounds?

What system is the one to use? The one to avoid?

Thanks for your help/information.
 
I gave this a try, and dropped it when I saw no improvement from the effort. Stuff is probably setting in the shop somewhere and gathering dust, grand kids will have a blast trying to figure what that is for. Remember the steering end of the bullet is the base "NOT" the front.

Roland
 
I trimmed and tipped for a while (the mepalts of that lot Bergers were ragged and nasty). The new lots of bullets are more uniform and less ragged, so I tip only these days. Some folks don't see a difference. I saw the difference in terms of needing less elevation to get to 1,000 yards (it was even more pronounced in the desert shooting at 1,900 yards).

The Hoover device is bullet specific (meaning he matches the bullet shape for each individual bullet); the older Whidden device made no attempt to match the shape and was universal to all 7mm or 30 cal. bullets. Whidden is now also trying to match specific bullet shapes with different inserts.

The Whidden die looks like it is based upon a Forester Ultra-Micrometer die. The Hoover is a very nice loooking custom die.

If price is a concern, then Whidden is or was less expensive (with the older caliber based tipping - not sure of the savings if you go with multiple bullet shape inserts). If price is not a concern or you only shoot one bullet and have no intention of changing, then the Hoover is a very viable option.

I have them both. I use the Hoover for my 7mm rifles (I have 3 inserts for different 7mm bullets), and the Whidden for my 6mm and my 338s.

I hope that helps

Jeffvn
 
Roland & Jeff are both right -- it depends.

Larry Bartholome, along with Dr. Oehler (of chronograph fame) tested a lot of bullets at 1,000 yards, using the then-new Oehler 43 with an acoustic target. That let them plot not only velocity, but time-of-flight. And that, when you think it over, let them plot velocity loss to target, caused by differing drag (B.C.)

Dave Tooley passed the raw data on to me, and Dave himself bought a model 43 and did further testing.

OK. There were bullets out there where B.C. (drag) varied from, say, .600 to .620. And that's worth 4 inches at 1,000 yards. In other words, the Model 43 lets you plot Standard Deviation and Extreme Spread for bullets, along with SD and ES for velocity.

Now from the data, the bullets with the lowest SD and ES for drag were plastic tipped bullets, like the A-max. That led Dave to start putting plastic tips in other bullets to tst the effect, and to eventually come up with the meplat trimmer -- tipping bullets, while the theoretically best solution, is a lot of work, and hard to do for those that don't have a very accurate lathe, collets, etc.

And the empirical data fits the theoretical model -- after weight, nose shape is the next most important factor in ballistic coefficient (drag). If your bullets have a consistent nose shape, there isn't all that much to gain by either trimming or pointing bullets. If the tips do vary, you're adding up to 3-4 inches to your group size at 1,000 yards.

Does the "increased B.C." from re-pointing bullets matter? Well, you're shooting at a known distance, so not for drop. Sure the re-pointed bullets hit higher. So what. Turn the sight up another click. As for wind drift, yes, lower drag helps here, too, just not as much as with drop. But it is a small amount, probably only significant if you always put the sight in the center of the bull & press the trigger, never trying to hold off for wind. Skll in holding off would be a far larger factor.

So, if you're wedded to bullets with a ragged nose shape, meplat trimming and repointing are worthwhile. If you shoot very good bullets (I don't mean brand name here), there is a very small gain offered by trimming and repointing, which should be way down on your list of "things that are important."

I actually do trim & re-point for 200 yard benchrest score shooting. I figure it's worth one more X (X-ring at 200 yards is a .125 inch dot) out of about 25 shots. And it's something to do while watching reruns on TV...

FWIW
 
Thanks - just the kind of information I was looking for.

I was considering the Hoover and thinking of just getting the pointing die, and not the metplat trimmer. I'm pretty much locked into Sierra 168 and 180 Match Kings on my 308win, so would get that pointing tip.

Now - I'm not sure the benefit justifies the outlay of dollars. In concept, the idea makes sense, just doesn't seem like it translates to accuracy improvement in the real world.
 
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Somewhere I used to have some plot sheets done from targets shot with bullets that had been pointed & trimmed vs. un-modified. There was a small, but noticeable difference in vertical @ 1k. The conditions would have to be very good for it to be a meaningful difference, and you'd have to be at the point where squeaking one extra point or X might make the difference btwn 1st and 2nd.

That said... for a .30 cal 168 or 180 SMK, I wouldn't bother. Get a better (in terms of BC) bullet first; that'll be a more worth-while use of your time/money. Those bullets are very accurate within their domain, but there are better options out there for this kind of competition.

YMMV,

Monte
 
Bullet pointing

I would have to disagree with some posters views on subject of bullet pointing.
there are a group of shooters in Otttawa at Connaught Ranges
http://www.dcra.ca/index.php

we all see the advantages of bullet pointing, 1/2 to 1.4 moa elevation with pointed bullets.
we use electronic targets that give speed of bullet at target out tom 900 m the es is lower much lower than non pointed bullets, and your groups are smaller, more V bulls.
i test pointed bullets with 90 gr Bergers in 223 rem fired 12 v bull and 3 bulls with pointed at 900m
then shot 12 shots at 900 non pointed shot 3 fours some bulls and 4 vbulls conditions were perfect 7.30 pm no wind 70 deg
i use and others use the Hoover system
 
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