Rifle Load with new Bullets

[Deleted noremaximus]

Good morning, I am currently running low on 140gr RDF bullets for my 6.5 Creedmoor. If I purchase more of the same bullets, would I have to redo the load development for the rifle? Or would my current load still be good with the purchased bullet? I'm concerned because the bullet would be the same but the lot size would be deferent. Thank you.

 

[JEFFPPC]

If you do not sort your bullets you more than likely will not see a difference. If you sort, just keep sorting.

 

[M-61]

My concern (?) is where is the ogive. Forget lot number to lot number you can drive yourself in the same box of 100. I have Hornady's to be the most erratic but that strictly my experience with one type of their bullet in one weight.

 

[Ranger188]

You "might" have to change the seating depth slightly.
They could be slightly longer or shorter BTO for a new lot.
That would be all I'd worry about.

 

[Deleted noremaximus]

Thanks for the info guys.

 

[Ned Ludd]

There is really no "set" answer to this question. This is largely because we cannot easily know every single dimensional and weight change that may be present between different Lots of the exact same bullet. I have had different Lots of the same bullet require a significant amount of tweaking to get the load back to where it had been with the previous Lot. I have also had new Lots of a bullet tune in EXACTLY where the previous Lot tuned in, even though I could actually measure significant differences in the average bullet dimensions between Lots. The only way to know for sure is to test. Even if you merely load up the new Lot of bullets identically to the previous Lot, then shoot a few groups and gather some velocity data, you will have a much better idea whether the load needs to be re-tuned.

The caveat to that type of "streamlined" comparison is that if even the new Lot of bullets seems to shoot very well using the exact same load as with the previous Lot, you cannot know with any certainty where the new bullet load falls within the optimal charge weight and seating depth windows previously identified. For example, it could fall within the optimal windows, but very close to one edge or the other rather than somewhere near the middle. That could mean the previous load with the new Lot of bullets would be much more likely to be affected by conditional changes, such that it could go out of tune more easily. The only way to be absolutely certain is to completely re-work a load any time you change a component. Obviously, that requires more time, effort, and barrel life, so when deciding how much you load development/testing to do with a new Lot of bullets, you probably want to weigh in the specific intended use for that load. Some purposes are more critical and may require additional diligence when changing components.

 

[338 dude]

Continue on as normal with the new bullets and let the target tell you

 

[Walt Schmidlin]

I use 6mm 105 RDFs, opened new box from a different lot. Had to adjust the seating stem to get the same dimension off the lands as the bullets from the prior lot.
No difference in groups at 600yds.
As previously noted above you will need to test, hope you are as fortunate as I was.