168gr SMK base to ogive measurements

[rgold1963]

I just got into a new box of 500 168gr SMK's. Checking COAL I was getting a lot more varience than normal. I load on a Dillon 650 and am not trying to make match grade rounds but I have never seen this much of a difference before. I got out the Hornady comparator and am seeing as much as 0.020 difference BTO going through the box. Also seeing larger weight differences between bullets in this batch. Going to see how they shoot but it might be time to try some other manufacturers to see if they are more consistent. I have another box of 500 from the same lot to get through as well. The previous lots I had were far more consistent and I just measured a bunch of finished rounds from the cartridge base to ogive and the biggest difference I saw was 0.005. Not sure what their acceptable range is but it seems like QC has slipped up with bullets like so many other things since Rona struck.

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[kmk1012]

We're these purchased from American Reloading by chance? I bought a bunch from them and had the same issue. They generally have good prices but there's normally a reason why they are selling them so cheap. Their company sell mostly pulled bullets and seconds quality items that did not meet the manufacturer specs. They are safe but not as accurate or consistent as buying from any other seller such as Bimart or Midway.

 

[rgold1963]

We're these purchased from American Reloading by chance? I bought a bunch from them and had the same issue. They generally have good prices but there's normally a reason why they are selling them so cheap. Their company sell mostly pulled bullets and seconds quality items that did not meet the manufacturer specs. They are safe but not as accurate or consistent as buying from any other seller such as Bimart or Midway.

Actually got them from Powder Valley! They were not pulls, 2nds, or blems.
What's interesting is I had some old packages from Midway that were labeled as blemished but they were far more consistent than these new boxes.

 

[DizzyJ]

I'd see how they shoot and go from there.

 

[DizzyJ]

.020" is a big variance. This is from a loaded round correct?

 

[rgold1963]

.020" is a big variance. This is from a loaded round correct?

Unfortunately. That is when I checkd the bullet base to ogive and found out that's where the problem lies. I am using the Forster ultra micromter seating die and my COAL has never been off anywhere close to this. I ran through about 1000 other bullets before opening these SMK's and see maybe 0.005 max variance, usually less.

 

[DizzyJ]

Is your neck tension consistent? Can you feel any difference when seating the bullets?

 

[ma96782]

I hear ya......about the COAL measurements. But then, also look at the tips themself. Add in the ogive and you might really get discouraged. So then, are you also spinning the bullets?

OMG?!?!

Anyway.....
I make too many assumptions about my stuff just based on the lot numbers theory. I say "theory" because yeah......who knows about the manufacturer's specs and QC.

Aloha, Mark

 

[TTSX]

What seating die are you using? I've found specifically with Lee that since it doesn't actually lock to my setting, consistency can suffer. If you have the tools to measure at the ogive, I don't understand why you'd be measuring loaded rounds instead of the bullets, then blame the bullet? Match bullets almost always have a darn flat base to measure off of

 

[ma96782]

I was assuming (yeah....not really a good idea) that he was using one of those "bullet comparator tools" (like the ones made by Hornady or Sinclair), to check the measurement of the bullet.

SINCLAIR INTERNATIONAL SINCLAIR INSERT STYLE BULLET COMPARATOR | Brownells

This Sinclair Comparator is an excellent tool to use to sort bullets by base to give length. This is a valuable step if you are considering trimming the bullet meplat. NOTE: When sorting a lot of bullets, a digital caliper is sometimes a better ch...

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Aloha, Mark

 

[rgold1963]

Is your neck tension consistent? Can you feel any difference when seating the bullets?

Yes. Neck tension is consistent. No difference when seating other than the final length.

 

[rgold1963]

I hear ya......about the COAL measurements. But then, also look at the tips themself. Add in the ogive and you might really get discouraged. So then, are you also spinning the bullets?

OMG?!?!

Anyway.....
I make too many assumptions about my stuff just based on the lot numbers theory. I say "theory" because yeah......who knows about the manufacturer's specs and QC.

Aloha, Mark

The bullet comparator goes off the ogive not the tip! Should be consistent since the seating die I use does the same but the bullet base to ogive distance is different from bullet to bullet.

 

[rgold1963]

What seating die are you using? I've found specifically with Lee that since it doesn't actually lock to my setting, consistency can suffer. If you have the tools to measure at the ogive, I don't understand why you'd be measuring loaded rounds instead of the bullets, then blame the bullet? Match bullets almost always have a darn flat base to measure off of

The Forster Ultra Micrometer seating die. I used the comparator which goes off the ogive once I saw how far off some of them were. The comparator showed that the actual bullets have quite a varience of bullet base to ogive length.

 

[ma96782]

The bullet comparator goes off the ogive not the tip! Should be consistent since the seating die I use does the same but the bullet base to ogive distance is different from bullet to bullet.

YES.

There is the method where you measure only the bullet (ogive to the base of the bullet).

Then, there is the common method, where you measure the total COAL (base of the cartridge to the tip of the bullet).

And then, there is also the method where you measure the loaded cartridge (from the ogive to the base of the cartridge).

Sorry if I got the post's measurement confused/incorrect.

Aloha, Mark

PS.....BTW what are you shooting the cartridges out of?

I ask because.....IMHO, some stuff just matters more, depending on the platform of the rifle.

 

[rgold1963]

YES.

There is the method where you measure only the bullet (ogive to the base of the bullet).

Then, there is the common method, where you measure the total COAL (base of the cartridge to the tip of the bullet).

And then, there is also the method where you measure the loaded cartridge (from the ogive to the base of the cartridge).

Sorry if I got the post's measurement confused/incorrect.

Aloha, Mark

PS.....BTW what are you shooting the cartridges out of?

I ask because.....IMHO, some stuff just matters more, depending on the platform of the rifle.

I measured all three once I realized how off some of the finished rounds were. It more than likely won't make a huge difference for close up shooting. I was just surprised at the huge difference in bullet to bullet measurement out of one box of 500 from Sierra.

 

[JJE76]

I've noticed it to. Loaded 100 today coal was 2.79-2.807, then loaded some A Max same die setting 2.8-2.803. Kinda odd but I'm new to this.