Guess lot# does matter

nhenry · Mar 3, 2023

Bought a few boxes of 140gr partitions off of a guy, when they got here they were different manufacturing lots. The packaging is from around the same time, but the bullets are different sizes. Will I have to develop a different load for the two profiles?

300WSM · Mar 3, 2023

nhenry said:
Will I have to develop a different load for the two profiles?

View attachment 19237

No.

TackDriver284 · Mar 4, 2023

Develop a load and find the one your rifle likes, and try 3 rounds of each lot and see if the POI is the same.
What are the ogive measurements on those two different lots? Just curious

RL338 · Mar 4, 2023

This is why I like to buy bullets in large lots to avoid this problem. For a benchrest shooter bullet consistency is a must , hunting there is some wiggle room. Do as TackDriver284 mentions and see your results.

xphunter · Mar 4, 2023

Good advice given.
I would shoot your old load (3-shot group) with the new bullets, and see what it does first. For hunting it may be a non-issue.
If things are wacky, do what is mentioned above.
Do you have any loaded ammo from your original bullets?
If you have the ability to measure from the head of the case to the ogive, set-up the new boxes of bullets to be the same as the older/original bullets

300WSM · Mar 5, 2023

Here's the thing...

If you were shooting BR then you wouldn't even be asking this question.
#1 you wouldn't be using partitions
#2 you'd know that tiny bit of difference will very well make a difference in BR shooting.

But...

#3
Will this still be effectively lethal with minimal change. Indeed. Now you're the beholder and the only one needing satisfied is you.
Moa and or sub moa can still be achieved here even without changing a thing.

Hitting an X every shot from for score is a lot different than having an effective lethal 3 shot group.
You already knew that I'm sure

ShadeTree · Mar 5, 2023

I have 3 different boxes of .308 150 gr partitions. I wrote on the boxes how far to the lands on my M70 30-06...........I did that because there was so much of a difference between 1 box and the next & so I'd know depending which box I'd be loading out of. Not saying that to denigrate them, great bullet, but yes, a person can run into a difference in bullets from a different lot, or a different time period. Most times not, but it doesn't take long to check.

NYDAN · Mar 5, 2023

I measure the Base-to-Ogive "touching the lands" length for each box of bullets. It is very easy to adjust the seating die to maintain a certain bullet jump that works for the cartridge/bullet/powder combination. Some boxes don't require any adjustment, but others do.

JD338 · Mar 5, 2023

It shouldn't make a difference. I have run into this and I found no noticable difference out to 800 yards.

JD338

300WSM · Mar 5, 2023

JD338 said:
It shouldn't make a difference. I have run into this and I found no noticable difference out to 800 yards.

JD338

This...

That's why from your question of will I need to work up additional loads...

The difference is negligible especially for a hunting platform/results