To trim (meplat) or not?

[Shooter13]

I started this thread not necessarily about just trimming the meplat but learning, learning more about a sport I love. This for me isn't the end but just the beginning. I KNOW how important it is to have a very well tuned gun, a stable platform to shoot from (front and rear rest) and be able to read flags and mirage, to be able to load a good round of ammo. I don't get as much time at the range as I'd like but if I did I'd probably be single again! So I guess all I can say is "to infinity and beyond!!" LOL we are never to old to learn maybe just to old to admit we don't want to learn something new.

 

[tom]

it's been mentioned but I've never seen where a target shot in that manner has been posted. Plenty have been on seating depths and powder charges. Sounds like a good project for this spring

That's exactly what we do, for every bullet. It's part of load developing, and follow up trips as necessary to compare the new "standard" vs xyz. Eventually you get your recipes for the different bullets you shoot. I shoot decent stuff, so once I have let's say a recipe for a Roy 103 on a Sierra jacket, or a vapor on a j4, I haven't found I needed a re "tune" . I lost a lot of pictures a couple years ago from a phone/genie lift wreck lol, otherwise I could have dug up a couple.

Jeff, I think that would be slower in my hands.

Tom

 

[gunnermhr]

That's exactly what we do, for every bullet. It's part of load developing, and follow up trips as necessary to compare the new "standard" vs xyz. Eventually you get your recipes for the different bullets you shoot. I shoot decent stuff, so once I have let's say a recipe for a Roy 103 on a Sierra jacket, or a vapor on a j4, I haven't found I needed a re "tune" . I lost a lot of pictures a couple years ago from a phone/genie lift wreck lol, otherwise I could have dug up a couple.

Jeff, I think that would be slower in my hands.

Tom

Tom I glad you replied, so what are your findings at 1,000 yards trimming and pointing, did you see improvements in the custom bullets? I assume you have and are still trimming and pointing? A few of my friends, (some that have collected a dollar bill form you, LOL) that are pretty successful in the 1000 yard paper game trim and point. I believe it's worth the time at that distance on paper, I'm not sure about 600, and 500 and under I don't believe it makes much difference, although I'm going to test this spring.

We have a big match here in PA in Ridgway, VBR, 1000 yard Steel silhouette where you shoot a life size crow @ 850, ground hog @ 900, bobcat at 950, and coyote @ 1000. I've been blessed with success at this match and do not point or trim. In fact the only sorting I do is by weight. The same guys I know who are very successful @ 1000 paper do well here but far from dominate.

A guy once told me he does 10 things for accuracy, only 8 matter, the question is what 8 matter? I think all 10 matter if you have trust in your equipment and abilities.

 

[JEFFPPC]

Jeff,
Are you suggesting using pins to measure the meplat diameter? If the concern is the diameter then why not measure and sort them that way.

 

[tom]

Tom I glad you replied, so what are your findings at 1,000 yards trimming and pointing, did you see improvements in the custom bullets? I assume you have and are still trimming and pointing? A few of my friends, (some that have collected a dollar bill form you, LOL) that are pretty successful in the 1000 yard paper game trim and point. I believe it's worth the time at that distance on paper, I'm not sure about 600, and 500 and under I don't believe it makes much difference, although I'm going to test this spring.

We have a big match here in PA in Ridgway, VBR, 1000 yard Steel silhouette where you shoot a life size crow @ 850, ground hog @ 900, bobcat at 950, and coyote @ 1000. I've been blessed with success at this match and do not point or trim. In fact the only sorting I do is by weight. The same guys I know who are very successful @ 1000 paper do well here but far from dominate.

A guy once told me he does 10 things for accuracy, only 8 matter, the question is what 8 matter? I think all 10 matter if you have trust in your equipment and abilities.

Not always, as left untouched shoots well enough in almost all cases to develop a solid tune. If I am going to f something up, it will be with trimming it seems. Never seen where I could screw anything up badly with just pointing, unless you really overdo it, and that should be noticeable.
But yes, almost all are improveable


Tom

 

[Shooter13]

I'm not sure about 600, and 500 and under I don't believe it makes much difference, although I'm going to test this spring.

Let us know what you find please. I don't intend on doing it as 98% of my shooting is <300.

 

[gunnermhr]

Let us know what you find please. I don't intend on doing it as 98% of my shooting is <300.

Will do, it's be March at the earliest.

 

[Ahhnother8]

Interesting timing. Just did a quick curiosity test last Saturday. Fired at 1000 yards in mild conditions with the shortest, longest, average length, trimmed only, and trimmed and pointed bullets all from the same lot# and all loaded exactly the same. So, five 5-shot groups all on the same e-target, without interruption. The average group sizes were all relatively similar, except with the shortest bullets, which was the worst group by 30%ish. The muzzle velocities were all similar, but the short bullets (huge meplat) arrived at the e-target from 60-100 fps slower than the rest, and as expected were the lowest on the target. If the longest and shortest were all combined into one group, the ES in elevation was about 16" and the velocity ES at the target was 103fps. Two bullets out of each 5-shot group went to the extreme of the 16" of elevation.

While trimming a batch, I did notice that all too often a short-ish and long-ish one get pulled from the bullet box consecutively. If they got loaded that way, without first trimming, the elevation would be ugly.

 

[DaveTooley]

A long time ago I investigated why at 1K we were getting the odd shot out of the group vertically. I got test data from Larry Barthlome and Ken Oehler. They tested for advertised BC's VS actual measured BC's. Larry was gracious enough to give a copy of the data. They set up two Oehler 43's one at 123yds and one at 1K and measured actual BC's. After studying the data I was drawn to the Hornady Amax's . They had the most consistent BC's out of 20 or so bullets that were tested. Then the question is why the Amax's? It was the meplat/tips. I got my own model 43 and started testing. I did a study for Sierra where I installed their tips in bullets from 22-338 . I measured BC's before and after. BC's were more constant w/tips. Then what to do about the meplat. I woke one day with an idea and came up with a trimmer. Then more testing. The bottom line is trimming improves BC consistency. I saw as much .030+ variation in BC with some lots of bullets. That matters at 1K. 600 probably. Out to 600 probably not so much. I always told people to get 50+% of the meplat trimmed and the rest will get lost in the noise. That's assuming your bullets are well made.

 

[JimPag]

I’m reading now, yes that’s dangerous for me. Do only the thousand yard plus (600 plus) guys trim and point (meplat)? Or is there a benefit for short range? I really can’t see one from what I’m reading but want to know your guys opinion. The more I read the post by @gunsandgunsmithing the more intriguing each aspect becomes.

Frankie. I received a bunch of metplat trimming stuff years ago from whoever I bought out all of their equipment and I talked to Bart about it because I figured if anyone would know it would be him. Well that stuff went down the road after I talked to him. He said for short range it's a waste of time. That's all I needed to hear.

 

[Ned Ludd]

There can be more than one reason to point bullets. Pointing for the purpose of improving the BC of the bullet to [slightly] reduce wind deflection is the reason most point, but consistency/precision may be improved even if the BC doesn't change much. For example, pointing may also reduce bullet BC variance (i.e. ES/SD values), even if the increase in BC is relatively small. The real question about pointing is whether the benefits are large enough to be significant as compared to other potential sources of error. Only testing can reveal this with certainty.

There are different ways of approaching the pointing process, and one has to find out for themselves whether any of them make a difference, and if so, how much? One method is to sort bullets by OAL into length groups of approximately .0015" to .002" or so, then point all the bullets without trimming from a single length group using the same pointing die setting. Because pointing pushes the edges of the meplat in toward the bullet axis of rotation, even jagged meplats can be markedly improved when pointed without trimming.

Alternatively, one can find the ~shortest bullet within a given Lot# of bullets, or even within bullets length sorted as described above, set the trimmer to clean up the meplat acceptably with that specific bullet, then use the same trimmer setting for the rest. Whether trimming meplats adds anything to the bullet pointing process again must be decided by the individual. In many cases it clearly does, but in some cases it may be that the effect of adding a trimming step may be difficult to quantify. Testing should reveal any clear and obvious differences. If it does not, the difference may be negligible.

Regardless of the chosen method, clear differences between pointed and un-pointed bullets are not difficult to detect, but with certain caveats. In my hands, the difference in the scope elevation setting required to center a group on target at 300 yd between bullets straight out of the box and those that had been length-sorted and pointed directly (i.e. not trimmed) was routinely anywhere from 1/8th to 1/4 MOA. That comes largely from the improvement of bullet BC by the pointing process. I'd imagine that at distances of 100 or 200 yd, it would be far more difficult to reliably detect such a small difference. However, I have also routinely observed length-sorted and pointed bullets to group more tightly than un-pointed bullets. So BC improvement may not be the sole benefit of sorting and pointing. It is not hard to envision how making bullet BC more uniform could generate better grouping, even if the BC wasn't markedly improved. In order to determine whether any pointing process has a significant effect, did I mention that testing is necessary? LOL.

As has been noted, the quality of the bullet itself may have a lot to do with how much effect will be observed after pointing or trimming and pointing. The higher the quality of the bullet, the more uniform they will generally be out of the box. Certainly there are some very, very fine bullets made that seemingly benefit little from sorting and/or pointing. Large scale production bullets typically have sufficient room for improvement that the benefits of pointing are not difficult to detect. Again, only testing can reveal whether pointing/trimming + pointing will be of some benefit. The good news is that testing the effect of pointing doesn't necessarily require huge numbers of loaded rounds, so the testing process does not have to be all that painful.

 

[WIB3]

You are not capable of tuning a turd. You can make it shoot better but can’t make it exceptionally better than others. Bottom line, start with the best, and do the homework. Test, test and test again. When you have all of that information figured out try to improve by pointing and trimming. The key is starting with the best possible components available. You can’t win matches shooting “good Bullets “ trying to make them better by pointing when the other guy is starting with exceptional Bullets. BR shooting, unfortunately is a game of money. That might offend some but ultimately is the truth. Time at the bench is equally important. Those who test and tune usually prevail.

 

[Dave M.]

I’m reading now, yes that’s dangerous for me. Do only the thousand yard plus (600 plus) guys trim and point (meplat)? Or is there a benefit for short range? I really can’t see one from what I’m reading but want to know your guys opinion. The more I read the post by @gunsandgunsmithing the more intriguing each aspect becomes.

Neither for 600 yard F open rifles. Not required to shoot clean scores.
For 1000 yard F open rifles, point only. Trimming is a waste of time from the testing and data I’ve reviewed. Read Litz’ book, he has done extensive testing on trimming and/or meplats.

 

[Tod Hendricks]

Trimming is about the last thing I test, once in a while its a positive improvement, more often it’s a negative. A couple times it was a drastic improvement, damn that’s what keeps me testing it.

Your own testing is the only way you‘ll know for sure. 600 yards or more will show a difference, not sure about shorter.