Inconsistant ogive lapua bullets?

[1951]

Good day,
First, I'm fairly new to reloading, I've only reloaded 980 rounds in three calibers.

I've loaded 500 rounds of 6.5 Creedmoor using Peterson brass and 140 grain Berger Hybrid target bullets. After some mistakes in the learning curve and load development, I was able to get my ammo where I wanted it with the powder charge and seating depth that gave me the best groups and consistent velocities.

After running out of the Bergers and not being able to source any, I Switched to Lapua 139 Scenars and started another load development. When I seating the Berger bullets they were all within a thousandth of an inch CBTOG. When seating the Lapua I can't seem to get them within five thou. I took the die apart and cleaned it, made sure the case bases where clean and the primers below the base, cleaned the shell holder, resized the necks to make sure the tension would be even between the lot of cases. Nothing seemed to help.

I measured the few remaining Berger bullets from the bullet base to the ogive and they are all pretty much the same, I measured the Lapuas from the bullet base to ogive and some are as much as five thou different than others. I suppose the bases could be longer in some than others but I'm starting to think the curve or diameter of the ogive with the Lapuas is different from one bullet to the next. If some of the bullet bases are longer it shouldn't result in a CBTOG difference once it's seated in the case.

Anyone run into this or have another explanation as to why I'm not getting consistant CBTO when seating the bullets?

Thanks

 

[wagonman]

last fall I bought a case of 1000 139 Lapua scenars and found them to measure better than your getting and better than the 142 smk I also use check your seating stem for fit.

 

[Dusty Stevens]

If the bullet measures that far off you just get what you get. Use those for fireforming and get a better bullet

 

[Straightshooter1]

Good day,
First, I'm fairly new to reloading, I've only reloaded 980 rounds in three calibers.

I've loaded 500 rounds of 6.5 Creedmoor using Peterson brass and 140 grain Berger Hybrid target bullets. After some mistakes in the learning curve and load development, I was able to get my ammo where I wanted it with the powder charge and seating depth that gave me the best groups and consistent velocities.

After running out of the Bergers and not being able to source any, I Switched to Lapua 139 Scenars and started another load development. When I seating the Berger bullets they were all within a thousandth of an inch CBTOG. When seating the Lapua I can't seem to get them within five thou. I took the die apart and cleaned it, made sure the case bases where clean and the primers below the base, cleaned the shell holder, resized the necks to make sure the tension would be even between the lot of cases. Nothing seemed to help.

I measured the few remaining Berger bullets from the bullet base to the ogive and they are all pretty much the same, I measured the Lapuas from the bullet base to ogive and some are as much as five thou different than others. I suppose the bases could be longer in some than others but I'm starting to think the curve or diameter of the ogive with the Lapuas is different from one bullet to the next. If some of the bullet bases are longer it shouldn't result in a CBTOG difference once it's seated in the case.

Anyone run into this or have another explanation as to why I'm not getting consistant CBTO when seating the bullets?

Thanks

It's not really unusual to find that much variance in bullet's BTO's, even within the same lot. This is why some reloaders sort their bullets by their bullet's BTO's. I bought 500 Lapua 144 FMJBT's (5 100 round boxes of the same lot) to practice with so as not to use up all my Berger 140 Hybrids' and when I went to sort them, they were very, very consistent, not varying more than .0005. After sorting a bunch from each box of 100 and not getting any more variance than that, I stopped and didn't measure all of them. This is the only batch of Lapua bullets I've ever tried, so maybe I'm just lucky to get a batch that's really good. I know with my Sierra bullets I've gotten a batch that was good like that only to find the next batch/lot with variance of .008.

Because of these variances I've found in various batches and the fact that the seating stem doesn't seat by a bullet's ogive, I now sort my bullets with a comparator that makes contact at the same place as my seating stem. This way when I seat the bullets, that variance in a bullet's BTO doesn't effect how far the bullet is seated into the case. You might think about doing the same . . .??? I found the contact point of a Sinclair 17 cal comparator very, very close to the same diameter as my LE Wilson dies seating stem ~.184" for the 6.5 cal bullets. Your seating stem my be different.

 

[JEFFPPC]

It's not really unusual to find that much variance in bullet's BTO's, even within the same lot. This is why some reloaders sort their bullets by their bullet's BTO's. I bought 500 Lapua 144 FMJBT'sj (5 100 round boxes of the same lot) to practice with so as not to use up all my Berger 140 Hybrids' and when I went to sort them, they were very, very consistent, not varying more than .0005. After sorting a bunch from each box of 100 and not getting any more variance than that, I stopped and didn't measure all of them. This is the only batch of Lapua bullets I've ever tried, so maybe I'm just lucky to get a batch that's really good. I know with my Sierra bullets I've gotten a batch that was good like that only to find the next batch/lot with variance of .008.

Because of these variances I've found in various batches and the fact that the seating stem doesn't seat by a bullet's ogive, I now sort my bullets with a comparator that makes contact at the same place as my seating stem. This way when I seat the bullets, that variance in a bullet's BTO doesn't effect how far the bullet is seated into the case. You might think about doing the same . . .??? I found the contact point of a Sinclair 17 cal comparator very, very close to the same diameter as my LE Wilson dies seating stem ~.184" for the 6.5 cal bullets. Your seating stem my be different.

I agree. This is a basis of Bob Greens tool. It's fast and easy. Works well for me.

 

[mac86951]

Good day,
First, I'm fairly new to reloading, I've only reloaded 980 rounds in three calibers.

I've loaded 500 rounds of 6.5 Creedmoor using Peterson brass and 140 grain Berger Hybrid target bullets. After some mistakes in the learning curve and load development, I was able to get my ammo where I wanted it with the powder charge and seating depth that gave me the best groups and consistent velocities.

After running out of the Bergers and not being able to source any, I Switched to Lapua 139 Scenars and started another load development. When I seating the Berger bullets they were all within a thousandth of an inch CBTOG. When seating the Lapua I can't seem to get them within five thou. I took the die apart and cleaned it, made sure the case bases where clean and the primers below the base, cleaned the shell holder, resized the necks to make sure the tension would be even between the lot of cases. Nothing seemed to help.

I measured the few remaining Berger bullets from the bullet base to the ogive and they are all pretty much the same, I measured the Lapuas from the bullet base to ogive and some are as much as five thou different than others. I suppose the bases could be longer in some than others but I'm starting to think the curve or diameter of the ogive with the Lapuas is different from one bullet to the next. If some of the bullet bases are longer it shouldn't result in a CBTOG difference once it's seated in the case.

Anyone run into this or have another explanation as to why I'm not getting consistant CBTO when seating the bullets?

Thanks

Is it a compressed load?

I also have been very happy with Lapua consistency, 6.5 139gr in specific, though manufacturing is manufacturing and tolerances happen. Measure the bullets and see if that's your variance, then look at where the seating stem is contacting the bullets, any chance you're getting a ring? Perhaps seating force is actually deforming the bullet in the process? Are your case necks too clean? What's your neck tension, IE what's the diameter of the neck before and after seating a bullet?
Brass length consistent? Any chance some necks are long and hitting the inside for the seating die (roll crimp?)

There's a few thoughts for you; I'm sure we can expand on that list. You do say Berger seats consistently, so I'm skipping thru a few commons, but everything is worth a re-visit. Verify the variance isn't the parts coming into the process first, you'd drive yourself crazy searching for the process solution when it's coming from an earlier step.

-Mac

 

[perazziguy]

I have some 6mm Lapua 105's and with the Hornady comparator, they are supremely consistent. I have not loaded any yet so I don't know how they will measure when seated. Maybe my wife will buy me a Bob Green comparator for my birthday, March is around the corner.....

 

[Straightshooter1]

I agree. This is a basis of Bob Greens tool. It's fast and easy. Works well for me.

Yup, this is it:

Welcome to Green's Rifles

Complete Bench & Varmint Rifles Precision Barrel Installation Superior Custom Dies and Tooling Specializing in craftsmanship

greensrifles.com

Wish I had know this earlier in my precision loading trek.

 

[Bc'z]

I suggest cleaning your comparator.
I shoot scenars in both 123gr and 136L's in .264 caliber. From what I've seen they measure better than Berger's.

 

[Texas10]

It's not the bullet!

In my experience, there are three variables that affect bullet seating consistency.
1. Seating stem fit to the bullet tip. Change stems, or epoxy bed one to fit perfectly.
2. Neck tension and inside the neck finish. Is there lube inside the neck, or powder fouling?
3. Charge weight, is it a compressed load?

If you're seeing that great of variation in seating depth, you probably should start looking closely at your loading process.

 

[jimmymac]

Thank God for the custom bullet makers, cranking out super consistent projectiles, one at a time on the same set of dies. The quality and service that some of these small time operators provide is outstanding.

 

[Toddy]

The Lapua projectiles take up a lot more case capacity if your chamber is throated for bergers. As mentioned above it may be a compressed load which is causing seating inconsistencies. For example with the 180 scenars in 7mm, the rifles throat needs to be approximately 80 thou longer than with the Berger 180 hybrids for the top of the boat tail to be above the neck/shoulder Junction.

 

[1951]

Thanks for the replies,
The inside of the necks are clean, no carbon, lube or anything else.

The shoulder bump is within a half thou for the lot of cases.

I full length sized the cases to get the cartridge base to shoulder datum all within 1/2 thou.

I ran the necks into a collet neck sizer die to get them all consistent.

I trimmed the cases to the same length.

It is not a compressed load.

Finding a different bullet here right now is almost impossible.

I'll make an insert for the comparator body that is the diameter of the seating stem. Seems logical to me the measurement from the cartridge base to that point of the ogive would be pretty much the same from cartridge to cartridge since that is where it's seated from , but if I then measure them with the insert I have now and they vary, like the rounds I just loaded, I'd say the consistentsy of the ogive curve is low quality.

I went to the trouble of finding my CBTO touching the lands where the part of the ogive that was touching the lands is close to point that touches the comparator insert. That is the measurement I am looking for when I seat the bullet, not the cartridge base to the tip of the bullet or cartridge base to 1/4" below the tip of the bullet. I want all the cartridges to have the same measurement from the base of the cartridge to the spot on the bullet that first contacts the lands when the bullet is fired, or as close as I can. I could keep making inserts of various diameters until I find one that measured the same when I seated all my rounds but it may not be consistent at the ogive land intersect point. Isn't that is why people measure the cartridge length to the ogive instead of the tip? If I seat the bullets and then measure the length to the point where the seating stem contacted the bullet, it just makes sense the measurements would be the same, but if the bullet's ogive curve is not the same from bullet to bullet the jump would be different from bullet to bullet as the seating stem point isn't where the bullet makes contacts with the lands. Or that's what I presume anyway, like I said I'm a novice.


I suppose it depends if we are trying to seat all the bullets so they all have the same amount of bullet in the case to keep the pressure constant from one shot to the next or if we are seating them so the part of the ogive that first contacts the lands is the same distance from the base in every cartridge.

I base to ogive sorted my remaining 680 bullets yesterday into four lengths, the shortest was 13% next up is 46% the next is 24% and the last is 17% Five thou from shortest to longest. Not as bad as the ones I loaded, they were about even, luck of the draw as I took them out of the box I suppose.

Or I'm overthinking this and really don't have a clue, which is a distinct possibility.

 

[Leeman]

How do they shoot compared to the Bergers, surely that is the only thing that really matters?

 

[mgunderson]

Are you sure the bullet tip is not hitting in the seating die? One of previous responses asked this.

 

[anschuter2013]

The OP stated "I measured the few remaining Berger bullets from the bullet base to the ogive and they are all pretty much the same, I measured the Lapuas from the bullet base to ogive and some are as much as five thou different than others".

It IS the bullet.

 

[Ned Ludd]

Thanks for the replies,
The inside of the necks are clean, no carbon, lube or anything else.

The shoulder bump is within a half thou for the lot of cases.

I full length sized the cases to get the cartridge base to shoulder datum all within 1/2 thou.

I ran the necks into a collet neck sizer die to get them all consistent.

I trimmed the cases to the same length.

It is not a compressed load.

Finding a different bullet here right now is almost impossible.

I'll make an insert for the comparator body that is the diameter of the seating stem. Seems logical to me the measurement from the cartridge base to that point of the ogive would be pretty much the same from cartridge to cartridge since that is where it's seated from , but if I then measure them with the insert I have now and they vary, like the rounds I just loaded, I'd say the consistentsy of the ogive curve is low quality.

I went to the trouble of finding my CBTO touching the lands where the part of the ogive that was touching the lands is close to point that touches the comparator insert. That is the measurement I am looking for when I seat the bullet, not the cartridge base to the tip of the bullet or cartridge base to 1/4" below the tip of the bullet. I want all the cartridges to have the same measurement from the base of the cartridge to the spot on the bullet that first contacts the lands when the bullet is fired, or as close as I can. I could keep making inserts of various diameters until I find one that measured the same when I seated all my rounds but it may not be consistent at the ogive land intersect point. Isn't that is why people measure the cartridge length to the ogive instead of the tip? If I seat the bullets and then measure the length to the point where the seating stem contacted the bullet, it just makes sense the measurements would be the same, but if the bullet's ogive curve is not the same from bullet to bullet the jump would be different from bullet to bullet as the seating stem point isn't where the bullet makes contacts with the lands. Or that's what I presume anyway, like I said I'm a novice.


I suppose it depends if we are trying to seat all the bullets so they all have the same amount of bullet in the case to keep the pressure constant from one shot to the next or if we are seating them so the part of the ogive that first contacts the lands is the same distance from the base in every cartridge.

I base to ogive sorted my remaining 680 bullets yesterday into four lengths, the shortest was 13% next up is 46% the next is 24% and the last is 17% Five thou from shortest to longest. Not as bad as the ones I loaded, they were about even, luck of the draw as I took them out of the box I suppose.

Or I'm overthinking this and really don't have a clue, which is a distinct possibility.

In my hands, the Berger bullets I regularly load have very little base-to-ogive length variance. On the other hand, the overall length variance typically runs from about .015" to .020" within a given Lot # of bullets. What that means is that the predominance of length variance resides in the nose region. By definition that also means that the ogive radii within a Lot # of these bullets also varies. In this particular situation, sorting bullets by overall length is sort of a "poor man's" Bob Green comparator. In other words, I'm sorting bullets by OAL, primarily for the purpose of obtain length groups for pointing purposes, but sorting by OAL also has the added benefit of improving consistency between the two contact points on the bullet ogive that are most critical for uniform seating depth. Namely, the contact point at which the caliper insert seats just above the bearing surface, and the point at which the seating die stem contacts farther out toward the meplat.

Bob Green's comparator specifically allows sorting of bullets between these two critical contact points on the bullet ogive, thereby allowing for more uniform seating depth/CBTO measurements without having to tweak the seating die micrometer for every bullet. The region of the bullet below where the caliper insert seats is really not so critical with regard to generating uniform seating depth. Some will argue it is critical for other important things, but that's another conversation. In other words, sorting bullets by BTO isn't likely to improve inconsistent seating depth issues.

Because your bullets also exhibit significant length variance within the base-to-ogive region, you will not simply be able to sort bullets by OAL like I do. You can certainly sort bullets by subtracting the BTO measurement from OAL measurement to generate length groups that have a more consistent nose length; i.e. length sort within the region where the two critical contact points lie. However, taking two measurements and subtracting would be a lot of work if you plan on sorting large numbers of bullets. In that scenario, simply buying Bob's comparator (or similar) would likely be worth the effort over the long run.

 

[Straightshooter1]

Thanks for the replies,
The inside of the necks are clean, no carbon, lube or anything else.

The shoulder bump is within a half thou for the lot of cases.

I full length sized the cases to get the cartridge base to shoulder datum all within 1/2 thou.

I ran the necks into a collet neck sizer die to get them all consistent.

I trimmed the cases to the same length.

It is not a compressed load.

Finding a different bullet here right now is almost impossible.

I'll make an insert for the comparator body that is the diameter of the seating stem. Seems logical to me the measurement from the cartridge base to that point of the ogive would be pretty much the same from cartridge to cartridge since that is where it's seated from , but if I then measure them with the insert I have now and they vary, like the rounds I just loaded, I'd say the consistentsy of the ogive curve is low quality.

I went to the trouble of finding my CBTO touching the lands where the part of the ogive that was touching the lands is close to point that touches the comparator insert. That is the measurement I am looking for when I seat the bullet, not the cartridge base to the tip of the bullet or cartridge base to 1/4" below the tip of the bullet. I want all the cartridges to have the same measurement from the base of the cartridge to the spot on the bullet that first contacts the lands when the bullet is fired, or as close as I can. I could keep making inserts of various diameters until I find one that measured the same when I seated all my rounds but it may not be consistent at the ogive land intersect point. Isn't that is why people measure the cartridge length to the ogive instead of the tip? If I seat the bullets and then measure the length to the point where the seating stem contacted the bullet, it just makes sense the measurements would be the same, but if the bullet's ogive curve is not the same from bullet to bullet the jump would be different from bullet to bullet as the seating stem point isn't where the bullet makes contacts with the lands. Or that's what I presume anyway, like I said I'm a novice.


I suppose it depends if we are trying to seat all the bullets so they all have the same amount of bullet in the case to keep the pressure constant from one shot to the next or if we are seating them so the part of the ogive that first contacts the lands is the same distance from the base in every cartridge.

I base to ogive sorted my remaining 680 bullets yesterday into four lengths, the shortest was 13% next up is 46% the next is 24% and the last is 17% Five thou from shortest to longest. Not as bad as the ones I loaded, they were about even, luck of the draw as I took them out of the box I suppose.

Or I'm overthinking this and really don't have a clue, which is a distinct possibility.

There's a huge number of posts that tend to emphasis on how much a jump works well and this often leads to many reloader's "chasing the lands". When I started precision reloading, I was one of those "chasing the lands". I sorted bullets by their BTO's but would still get variations in CBTO, which of course meant I wasn't getting consistent jumps and I attributed some of that variance I was seeing on paper to that. I hadn't thought about the variance in the seating depth even though I knew seating depth was something significant and used to fine tune a load. It wasn't until I stopped "chasing the lands" and put two and two together that I figured out how much more important consistent seating depth is than the amount of jump for finding and keeping good and consistent accuracy (like, keeping within the accuracy node).

To get a consistent seating depth into the case the distance from the seating stem contact point to the bullet's base has to be the same. There's often a significant difference from the contact point of a comparator measuring the ogive and the contact point of the seating stem and this effects the seating depth. When the seating depths are consistent, the CBTO's usually are not, which means there's a variance in the jump. That variance in jump is of almost no consequence and the benefit of the consistent seating depths far outweighs it. My experience doing this has improved my groups on paper, as well as my chrono ES's.

Keep in mind though, this has to do when seating bullets with a jump, not when using the loading practice of touching or jamming the bullets.

Since I now sort my bullets by the seating stem contact point, the only time I'm concerned about the CBTO is when I want to know the distance is to lands in order for a jump starting point and to track the throat erosion. Otherwise, I find no other use for a CBTO measurement.

 

[Bill K]

Another good reason to buy Hornady, Berger, Barnes and Sierra bullets.

 

[1951]

Well, thanks again.

My accuracy was better with the Bergers than it is with the Lapuas. And I had no problems seating the Berger bullets, with the same die I'm using now with the Lapuas and and getting very consistent CBTO measurements.
If they ever become available again in my lifetime I'll get some more.
But now I'm kinda stuck with what I have.

Now I'm not the best shooter around either, wont see me winning any competitions, I can usually keep the groups an inch or smaller at 100 yards but It's closer to 1/2 with the Bergers. But as I'm not that accurate/good a shooter I want all the advantages I can get with a load that is consistent shot to shot. I need all the help I can get.

Tip is not bottoming out in the seating die, didn't with the Bergers either which have a sharper point than the Lapuas.

Yes I think it is the bullet too, but I've got a few hundred of them and want to load them to get the best cartridge I can with what I've got to work with.

I'm not shooting touching the lands and have no desire to chase them either. As with the Bergers I got the powder charge that gave me the best consistent velocities and groups, then I adjusted the seating depth away from the lands until I got a depth that gave me the best groups that had very similar groups at longer jump. That way as the throat erodes the seating depth will still be in a good group length. Don't know if I explained what I meant there. Right now I'm at 24 thou off the lands, The groups and velocities were similar up to 30 off.

Until I get an insert the diameter of the seating stem, I will load a few rounds with bullets out of the four base to ogive groups and see how they compare when seated within the groups.

Thanks again