A tale of three lots (bullets).

[Allen Corneau]

I just got in ten new boxes of Berger 6mm 115 grain VLD bullets from a clearance sale at Midway ($25 a box!).

Five boxes are from lot 4414, the other five from lot 4422. Since the lot I've been currently using (2946) is a third lot I thought I would see how different the three lots were to each other, something I knew was a thing but I had never quantified for myself.

I pulled 10 samples from each lot, measured the weight on my Creedmoor scale, and measured the base-to-ogive with a Forster comparator. The results are as follows...

Lot 2946:
Avg weight: 115.00 grains; ES: 0.08; SD: 0.03
Avg BTO: 0.7088; ES: 0.003; SD: 0.001

Lot 4414:
Avg weight: 114.98; ES: 0.16; SD: 0.05
Avg BTO: 0.7212; ES: 0.0040; SD: 0.0012

Lott 4422:
Avg weight: 114.99; ES: 0.14; SD: 0.04
Avg BTO: 0.7106; ES: 0.0010; SD: 0.0005


I'll use close to five boxes of these 115's over the course of a year for my Silhouette competitions (Ram load), so five boxes of each lot lines up nicely with my spring-time tuning for the next year.

I know this info doesn't mean much to most folks, but I thought since I went through the trouble of doing the measurements for my own curiosity I would share them with you folks.

 

[DLT]

I just got in ten new boxes of Berger 6mm 115 grain VLD bullets from a clearance sale at Midway ($25 a box!).

Five boxes are from lot 4414, the other five from lot 4422. Since the lot I've been currently using (2946) is a third lot I thought I would see how different the three lots were to each other, something I knew was a thing but I had never quantified for myself.

I pulled 10 samples from each lot, measured the weight on my Creedmoor scale, and measured the base-to-ogive with a Forster comparator. The results are as follows...

Lot 2946:
Avg weight: 115.00 grains; ES: 0.08; SD: 0.03
Avg BTO: 0.7088; ES: 0.003; SD: 0.001

Lot 4414:
Avg weight: 114.98; ES: 0.16; SD: 0.05
Avg BTO: 0.7212; ES: 0.0040; SD: 0.0012

Lott 4422:
Avg weight: 114.99; ES: 0.14; SD: 0.04
Avg BTO: 0.7106; ES: 0.0010; SD: 0.0005


I'll use close to five boxes of these 115's over the course of a year for my Silhouette competitions (Ram load), so five boxes of each lot lines up nicely with my spring-time tuning for the next year.

I know this info doesn't mean much to most folks, but I thought since I went through the trouble of doing the measurements for my own curiosity I would share them with you folks.

I appreciate your work. I don’t know how much closer different lots could be. Probably says a lot about Berger

 

[Bc'z]

Looking at the numbers I'd shoot lot 4414 last

 

[Allen Corneau]

Looking at the numbers I'd shoot lot 4414 last

Just going by the numbers, 4414 is the "worst" lot out of the three, so I would agree.

However, these are all well within my needs for Silhouette. If I were shooting benchrest or F-class (belly benchrest) then the variances within a given lot might come into play.

The take-away for me is to double-check the load when switching lots, especially seating depth.

 

[Ringostar]

Now try measuring them base to seating stem contact.

 

[DaveTooley]

Load several from each lot. Then compare seating depths, not COAL. If they were made with the same point up die they should be very close because ogive profile will be the same. BT to ogive is only a reflection of the point up die adjustment. It's comparable to shoulder bump numbers. Just an adjustment in or out.

 

[jelenko]

I thought the difference in BTO with 4414 was a lot. I thought that measurement/spec was supposed to be held to a couple thousandths. Is that not right?

 

[barefooter56]

Check " WHY BERGERS" here: https://bergerbullets.com/information/why-berger/

 

[Allen Corneau]

Now try measuring them base to seating stem contact.

I'm not sure why that would matter.

I load three different bullets/rounds for Silhouette. When I'm doing a particular load I'll adjust the seater to wherever it needs to be to end up at the desired BTO measurement. If that's +/- 0.002" on the seater's micrometer from a previous batch of bullets then so be it.

Also, if I'm switching to a new batch of bullets I'll double check the seating to make sure it's still good to go. If not, adjust accordingly.

 

[gunsandgunsmithing]

I've seen a lot worse than those numbers from lot to lot. FWIW, when I made my own bullets I'd shoot my culls that were as far as a full grain different in weight. They shot in the same little hole though! I pretty much stopped judging bullets by weight consistency after that.

 

[linebaugh]

Like learning from you guys. Many times I will buy enough bullets and powder to burn a barrel out but to be honest I have never given much thought to my hunting and plinking rigs. And I have never beasured a bullet beyond rudimetory.

Okay that said, gunsandgunsmithing apoke to this, how much real world difference in accuracy and ballistics are you seeing in different lots.

 

[Ringostar]

I'm not sure why that would matter.

I load three different bullets/rounds for Silhouette. When I'm doing a particular load I'll adjust the seater to wherever it needs to be to end up at the desired BTO measurement. If that's +/- 0.002" on the seater's micrometer from a previous batch of bullets then so be it.

Also, if I'm switching to a new batch of bullets I'll double check the seating to make sure it's still good to go. If not, adjust accordingly.

If you’re measuring your 6mm bullets with a standard 6 mm comparator. Then the area that you’re measuring to, isn’t really where it contacts the rifling. I had different lots of Lapua bullets that had different measurements using that method. Then I decided to measure at seating stem contact and the lots measured the same dimension from base. I decided to load test the different lots at same seating depth from stem. They shot identical, which makes me feel that it’s a more important measurement. After that I measure my 7mm bullets with a 6mm comparator, because it contacts at same place as seating stem. It might be worth checking it out.

 

[COLT45SA]

I just got in ten new boxes of Berger 6mm 115 grain VLD bullets from a clearance sale at Midway ($25 a box!).

Five boxes are from lot 4414, the other five from lot 4422. Since the lot I've been currently using (2946) is a third lot I thought I would see how different the three lots were to each other, something I knew was a thing but I had never quantified for myself.

I pulled 10 samples from each lot, measured the weight on my Creedmoor scale, and measured the base-to-ogive with a Forster comparator. The results are as follows...

Lot 2946:
Avg weight: 115.00 grains; ES: 0.08; SD: 0.03
Avg BTO: 0.7088; ES: 0.003; SD: 0.001

Lot 4414:
Avg weight: 114.98; ES: 0.16; SD: 0.05
Avg BTO: 0.7212; ES: 0.0040; SD: 0.0012

Lott 4422:
Avg weight: 114.99; ES: 0.14; SD: 0.04
Avg BTO: 0.7106; ES: 0.0010; SD: 0.0005


I'll use close to five boxes of these 115's over the course of a year for my Silhouette competitions (Ram load), so five boxes of each lot lines up nicely with my spring-time tuning for the next year.

I know this info doesn't mean much to most folks, but I thought since I went through the trouble of doing the measurements for my own curiosity I would share them with you folks.

That's really interesting~! Now I wonder how much of a factor those variances are when it gets down to what we are trying to accomplish when shooting. It seems like it would have some influence on how the bullet travels, but weighing bullets is a bit over the top for me~!

 

[ELR LVR]

Load several from each lot. Then compare seating depths, not COAL. If they were made with the same point up die they should be very close because ogive profile will be the same. BT to ogive is only a reflection of the point up die adjustment. It's comparable to shoulder bump numbers. Just an adjustment in or out.

Cool info, Love learning something new since I have not made bullets yet.

 

[ELR LVR]

If you’re measuring your 6mm bullets with a standard 6 mm comparator. Then the area that you’re measuring to, isn’t really where it contacts the rifling. I had different lots of Lapua bullets that had different measurements using that method. Then I decided to measure at seating stem contact and the lots measured the same dimension from base. I decided to load test the different lots at same seating depth from stem. They shot identical, which makes me feel that it’s a more important measurement. After that I measure my 7mm bullets with a 6mm comparator, because it contacts at same place as seating stem. It might be worth checking it out.

Good points made here, very good insight
(this just adds to the amount of Rocket Science involved with ballistics)

 

[jelenko]

If you’re measuring your 6mm bullets with a standard 6 mm comparator. Then the area that you’re measuring to, isn’t really where it contacts the rifling. I had different lots of Lapua bullets that had different measurements using that method. Then I decided to measure at seating stem contact and the lots measured the same dimension from base. I decided to load test the different lots at same seating depth from stem. They shot identical, which makes me feel that it’s a more important measurement. After that I measure my 7mm bullets with a 6mm comparator, because it contacts at same place as seating stem. It might be worth checking it out.

How are you measuring 'base to seating stem contact point'?

 

[JEFFPPC]

If you’re measuring your 6mm bullets with a standard 6 mm comparator. Then the area that you’re measuring to, isn’t really where it contacts the rifling. I had different lots of Lapua bullets that had different measurements using that method. Then I decided to measure at seating stem contact and the lots measured the same dimension from base. I decided to load test the different lots at same seating depth from stem. They shot identical, which makes me feel that it’s a more important measurement. After that I measure my 7mm bullets with a 6mm comparator, because it contacts at same place as seating stem. It might be worth checking it out.

I think the absolute number has no meaning you just need a consistent reference point. The consistency is what's important. If you want to get down to brass tacks measure the length from the front ogive to the tip and sort. Then sort those lots base to ogive. Now when you load you will be plus or minus .0005 if your precise and, your cases are properly prepared. I don't think where the stem rides has anything to do with it. Just what works for me.

 

[DaveTooley]

After several years shooting 1K BR we had evolved to the point bullets were the limiting factor. Coming from the short range game and having made bullets for many many years I knew we needed the most accurate bullet we could make. Several of us convinced Randy Robinette to make us a flat base bullet. Flat base is easier to make than a boattail. Randy made a 187 gr bullet that was just easy to tune and shot very well. No need to measure anything. While this was moving along I noticed many of us had unexplained vertical fliers. Studying the bullet holes it clearly showed some bullets had a bit of yaw in them. Meplats passing through the paper off center. I had heard of a test Dr. Oehler and an F-class shooter, Larry Bartholomew, had done. They setup Oehler 43's at 127 yds and 1K yds. They tested 20 some bullets measuring BC's. Larry kindly shared the test results. I studied them for several evenings. The bullets with most uniform BC's, muzzle to target, were Hornady A-Max's. A light came on. It's the meplat dummy. Early one Saturday morning I went to the shop and made a meplat trimmer. It didn't take a rocket scientist to see that trimming the meplats to a uniform shape and diameter was an improvement. Bullet holes showed much less yaw. Meplats centered up. That lead to me getting a 43's myself and testing. Meplats matter. That lead to a test for Sierra where I installed their green varmint tip from 22 to 338 caliber. That proved to be even better. We got a slight increase in BC instead of a slight decrease from trimming the meplat. I remember one test shooting Sierra 105's. We had .020" difference in the BTO measurement out of the same box. Sierra does a much better job these days not mixing lots. We determined modest differences in length, BTO, do not matter in a given lot. Even .020" difference in BTO length got lost in the noise. We sorted every which way you could think of and it did not change much of anything. Obviously you want consistency within a given lot of good bullets. But slight variations did not show any change in performance. When shooting HPBT's unless you trim meplats, any use of OAL is misleading at best as the meplat has no relationship with the rest of the bullet. It's shape, form, length is a function of the lube, the point up die and the press stroke.
Bottom line is
WHAT DOES THE TARGET TELL YOU

 

[Ringostar]

How are you measuring 'base to seating stem contact point'?

I took a 7mm bullet and inserted into seating stem, then marked with a sharpie on bullet at edge of stem. Then checked with comparator inserts, and found the 6mm insert contacted at the same place. I have actually considered getting the Sinclair sorting stand with dial indicator. Then actually using an LE Wilson seating stem as my comparator. I just feel that a base to seating stem is a more important place to measure. It’s something that we actually have control over while seating bullets.

 

[Ringostar]

Here’s something to consider, the standard comparator inserts don’t actually touch the bullet at the same place that the bullet touches the rifling. So is it really a critical place to measure? Also I’ve never seen any testing on this, but if we’re jumping bullets. Is it really the distance to lands that’s important, or is it the internal case volume with a seated bullet? Since rifling wears with continuous shots, then your measurement there is changing as you shoot. People have found that chasing the lands isn’t that important.