Chasing Ogives around

[DucNutz]

I seem to have this problem with ELD-X's I/m using the VLD seater with them. They also have the greatest weight difference of most bullets I load. I'm fine tuning a berger load and have been very happy with their consistency.

 

[YZ-80]

I seem to have this problem with ELD-X's I/m using the VLD seater with them. They also have the greatest weight difference of most bullets I load. I'm fine tuning a berger load and have been very happy with their consistency.

I know. But it seems to me that they shoot good!

 

[DJ Fergus]

Ever find yourself seating bullets and getting CBTO variations of up to .007"? Today I was loading up some 143 ELD-X's for my 6.5 x 47 and usually, at the same setting on my Redding micrometer seating die, I might get .001-.002 variation and I usually don't sweat it. Anything over .002" gets my tightie-whites in a knot and I start correcting them. Sometimes, one will seat right on the money and the next one is .004" too deep. That's when I give it a couple of gentle taps with the kinetic hammer, knocking it out past the CBTO and then adjust the die and seat it again. Anyway, I have a feeling that this has something to do with lot to lot variation but what do you do when it happens? How much variation is acceptable to you?

I've heard this story before multiple times with eldx bullets. I shoot mostly eldm bullets. Some Berger.

 

[DucNutz]

I know. But it seems to me that they shoot good!

Yeah, i still use them in my kids 7mm-08, and would still use them in my 280 AI if I could get them to shoot better than the bergers. They work on game which is a big factor for me.

 

[YZ-80]

Yeah, i still use them in my kids 7mm-08, and would still use them in my 280 AI if I could get them to shoot better than the bergers. They work on game which is a big factor for me.

Yeah, it shoots them pretty good. A little over .5 MOA for me at 300 so I guess I can put up with a little bit of variance. The ELD-M works great in my .308s too but like folks say, the ELD-Ms seem to be a product of better Quality Control.

 

[Savage 12BVSS]

I like to count on the firing residue inside the neck as the friction layer. I simply run a polymer brush in and out of the case neck once to burnish it slightly.

This really works for me.

If your seating stem is bottoming out on the tip of the bullet, that will cause variations in seating depth. I don't know what die you're using but I do know that Redding offers both standard and VLD seating stems. The standard will bottom out on the nose of some VLD bullets.

This is a real probability.

I like to see a +/- .001 on my CBTO measurements. I load Nosler Accubonds and within the same lot, I get good consistency. When I change lots, I will set my seating die about .005" high, seat a few, then adjust my seating die to achieve my target measurement. Going to different lots, you may see a .005 difference. Also, your caliper could be part of the problem too. Some of the cheaper ones are not precise and may not hold their zero

This quote leads me to believe there is a lot of variance in different bullets. I use accubonds as well and see +/- .001 and never sweat the difference. Sounds like the bullets are very accurate for you so maybe something to deal with in whatever way you have to.

 

[Doug Herold]

The problem is either in your bullet or your caliper tool.
Measure base to Ogive on every bullet; not a "sample". It's great you are using a Bullet Comparator Tool to do that. Additionally, I personally weigh each bullet to confirm consistency.
When you have built a round and you check for C.OA.L. from case head to Ogive you state that you observe inconsistency. Whenever that occurs, run your calipers back down and check to see of they come back to zero. If they don't, that's your problem. Finally, the rounds that are outside your 0.002" required COAL, set aside as a group. Shoot that group of rounds and compare to a control group which meets your standards. You may be surprised that they do not differ. Live fire is the only way to prove data. Shoot the two groups in a Round Robin style, i.e., shoot 1 round from group "A". then one round from Group "B" in alternating fashion at two different respective targets. Then analyze your data. Are you getting the MOA group size that you want? How far do you shoot? Are you content with 1.5 MOA or do you only want 0.25" MOA? Only you can answer these questions. Everyone is in a different place in terms of what is "good enuf". For sure, it ain't your brass (Lapua) and it ain't your die ( I think you said you are using a Redding "S" type), so it has to be the above.
Ohh, BTW, one tip I'll pass on is this: as you begin to seat your bullet in the case, just bump it slightly with the ram, then rotate the case/bullet with your thumb & index finger. I do this @ 6x per round to insure that the entire case is rotated. My run out (concentricity of the round) is excellent every time.
Good luck
Doug

 

[YZ-80]

The problem is either in your bullet or your caliper tool.
Measure base to Ogive on every bullet; not a "sample". It's great you are using a Bullet Comparator Tool to do that. Additionally, I personally weigh each bullet to confirm consistency.
When you have built a round and you check for C.OA.L. from case head to Ogive you state that you observe inconsistency. Whenever that occurs, run your calipers back down and check to see of they come back to zero. If they don't, that's your problem. Finally, the rounds that are outside your 0.002" required COAL, set aside as a group. Shoot that group of rounds and compare to a control group which meets your standards. You may be surprised that they do not differ. Live fire is the only way to prove data. Shoot the two groups in a Round Robin style, i.e., shoot 1 round from group "A". then one round from Group "B" in alternating fashion at two different respective targets. Then analyze your data. Are you getting the MOA group size that you want? How far do you shoot? Are you content with 1.5 MOA or do you only want 0.25" MOA? Only you can answer these questions. Everyone is in a different place in terms of what is "good enuf". For sure, it ain't your brass (Lapua) and it ain't your die ( I think you said you are using a Redding "S" type), so it has to be the above.
Ohh, BTW, one tip I'll pass on is this: as you begin to seat your bullet in the case, just bump it slightly with the ram, then rotate the case/bullet with your thumb & index finger. I do this @ 6x per round to insure that the entire case is rotated. My run out (concentricity of the round) is excellent every time.
Good luck
Doug

Thank you Doug. Very good points. The caliper does return to zero in the scenario you describe. I'm typically looking for .5 MOA out of my rounds and usually can achieve that, sometimes a bit better. I can see where the testing you have suggested would certainly help flesh out any accuracy differences, and I agree that in all probability, .002" ain't gonna make much of a difference. My Redding dies do produce very concentric rounds, but I'll definitely try this case rotation trick with my RCBS dies that sometimes produce .004-.005 runout.