Anybody trimming the meplat on their match bullets? I'm just wondering if anyone has noticed any improved accuracy by doing so. Also, if you're trimming them are you doing it after you seat the bullet or before? Thanks.
Meplat trimming of match bullets????
- Thread starter armorman
- Start date
I am not sure anyone trims only any more. Most people combine the trimming with pointing or tipping the bullets to a reduced point, increasing BC.
I have a Dave Tooley trimmer and it works great however the loss in BC is enough for me to stay away from the process until I get a pointing die. (For my shooting)
As to the affects of trimming, it has been observed by the majority of people who have trimmed that the grouping is more round. Unlike the more common vertical experienced in some untrimmed bullets. This has to do with the more consistant nose diameters.
If you were only going to do one of the processes I would suggest getting a pointing die.
Trevor
I have a Dave Tooley trimmer and it works great however the loss in BC is enough for me to stay away from the process until I get a pointing die. (For my shooting)
As to the affects of trimming, it has been observed by the majority of people who have trimmed that the grouping is more round. Unlike the more common vertical experienced in some untrimmed bullets. This has to do with the more consistant nose diameters.
If you were only going to do one of the processes I would suggest getting a pointing die.
Trevor
Fixed it. Hotlinking is ok to any site that doesn't compete with a board sponsor.
I bought the Sinclair meplat trimmer for 6.5, and I found that because of the angle of the taper and/or the softness of the plastic bushing, I could not get the bullet to seat solidly at one consistent depth. I think that trimming them inconsistenly might make things worse not better, so I just put the thing away and don't bother anymore.
BTW, I was using Lapua Scenar 139 and Sierra Matchking 142 bullets.
BTW, I was using Lapua Scenar 139 and Sierra Matchking 142 bullets.
I'm not questioning your above statement, but I find this interesting reading:
"Uniforming the meplat reduces the ballistic coefficient of the bullet by approximately 2%."
...from D.Tubb's website of Superior Shooting Systems:
http://www.davidtubb.com/tcom_images/reloading/bmu_one.html
Pointing the bullets will increase the BC which will negate the 2% loss from the uniforming of the Meplat.
Cynide is correct
the recommend process is to metplat and then point to restore and improve the tip of the bullet. Guys are trimming first to a uniform length and then pointing them to close them to a smaller dia then factor..
As an FYI some one another board asked a similar question and Dave tooley himself responded with a interesting post
I'll jump in since I made the first meplat trimmers and I manufacture the trimmer for David Tubb. You want to reference off the ogive. The goal is to have an in-flight, nose on, profile as uniform as you can get. That means all the meplats needs to be as close to the same diameter as possible. The only area that should be consistent from bullet to bullet is the ogive and the diameter. Thus my meplat trimmer mates up to a location on the ogive, not unlike the lead angle in a chamber.
What happens to a bullet that hasn't had the meplat trimmed is the non uniform air flow over the meplat creates in-flight yaw. That yaw varies from bullet to bullet thus the frontal profile varies and the BC's vary. You can get as anal as you want over things like this but you reach a point that you can't see the difference on the target. All I do is trim meplats. I have some unproven ideas about hitting a bullet on the tip and expecting it not to change along the ogive.
Dave Tooley
the recommend process is to metplat and then point to restore and improve the tip of the bullet. Guys are trimming first to a uniform length and then pointing them to close them to a smaller dia then factor..
As an FYI some one another board asked a similar question and Dave tooley himself responded with a interesting post
I'll jump in since I made the first meplat trimmers and I manufacture the trimmer for David Tubb. You want to reference off the ogive. The goal is to have an in-flight, nose on, profile as uniform as you can get. That means all the meplats needs to be as close to the same diameter as possible. The only area that should be consistent from bullet to bullet is the ogive and the diameter. Thus my meplat trimmer mates up to a location on the ogive, not unlike the lead angle in a chamber.
What happens to a bullet that hasn't had the meplat trimmed is the non uniform air flow over the meplat creates in-flight yaw. That yaw varies from bullet to bullet thus the frontal profile varies and the BC's vary. You can get as anal as you want over things like this but you reach a point that you can't see the difference on the target. All I do is trim meplats. I have some unproven ideas about hitting a bullet on the tip and expecting it not to change along the ogive.
Dave Tooley
I've just made myself a meplat reforming tool to use in the lathe. I put the bullet in a collet(cyclematic 618EVS lathe) and have the hardened form tool in the tailstock, 2000rpm and just a touch of lube and it closes the hole right up and seems to even up the lengths at the same time, would use a collet stop of doing many for even better repeatability. On the 139gr it makes it about .005" longer, 123gr stayed pretty well the same as it has a tighter nose to start with. Right now I do a 90° point(included angle), but will try a 60° once I order the right chamfer mill to make another forming tool, or take the 82° out of the vmc and will see if it makes any difference, should follow the bullet contour more closely. I had looked a bit into the type to use in a press, but wasn't that into putting pressure on a bullet like that, where as with the spinning motion in the lathe the forming takes nearly no force at all. Just wish I had a cnc lathe(maybe next year...) that would allow me to turn my own bullets from copper and brass.
I have both pointing and trimming tools. At the distances I normally shoot at I didn't see enough difference when trimmed and pointed in comparison to just pointed. I think if I was going to 1000m or farther I might see some difference. But for me I just point. The Berger hybrids and Otm/BTs close up really nicely!
I think its a waste of time but thats just my opinion. I'd rather spend more time shooting at long distance and learning how to the read the wind and conditions etc. I guess you can get as anal as you want but even world class competition shooters don't all do it. If you think it will make a difference, fill your boots.
Half of shooting little groups is the shooters confidence and ability. Anything that increases confidence, decreases groups! So if someone tells me that talking to their bullets prior to firing them increases accuracy, I don't disagree, however meplat uniformity is also scientifically proven, it's just way beyond my personal ability to tell!
I have shot trimed & pointed Berger 90gr in 223 shot 15 shots at 900m 12 of 15 in 5" circle could never do that with non pointed.
With a Sierra Match 155gr 30cal the New Palma bullet
you will gain 1 moa elevation over a non pointed and tyhey are better than non pointed. The mepplate trimmer that comes with Hoover bullet pointer is great very solid not like Sinclair
manitou
With a Sierra Match 155gr 30cal the New Palma bullet
you will gain 1 moa elevation over a non pointed and tyhey are better than non pointed. The mepplate trimmer that comes with Hoover bullet pointer is great very solid not like Sinclair
manitou
- Location
- Calgary Ab
Just wondering where you purchased this combo from. Is it one of our CGN sponsors ?
Thanks
This technique has been used for 100 years by precision shooters, it usually has no effect on terminal performance of the bullet. IIRC correctly it started with early war snipers and long range enthusiasts during WW1.
