Micrometer seating die?

[Papajoe222]

I purchased a Forster set of dies for my .223Rem loads and couldn't get a satisfactory answer to the following question on another forum. I'm hoping you guys can help out.
I load to .005 off the rifling and this micrometer die will allow me to set every round at the same CBTO measurement. Should I adjust for every round, or set it and leave it?

[Flyeralan]

Great question, my take on this is that I leave the die set. The difference must come from ogive changes on the bullets. If I am wrong, I'd love to know.

[Sgt Greybeard]

Great question, my take on this is that I leave the die set. The difference must come from ogive changes on the bullets. If I am wrong, I'd love to know.

In my experience so far, you are correct. Variances with a thou or thou and a half are normal.

Sent from my LM-V405 using Tapatalk

[JeffreyDeGraff]

Set it and leave it. Bullets will vary, if you correct it in one place, that variance will show up in another.


JTD

[Papajoe222]

So I loaded up 6ea. Adjusting micrometer for each round to achieve an identical measurement to the ojive and the others by setting the die for the first round and leaving it set for the other five.
Loading Barnes Match Burners groups were almost identical, only 2mm difference @100m.
Loading Sierra TMKs both groups measured out @ 9mm, with the ‘flyer’ opening up the group of individually set rounds by 2mm
My deduction based solely on this information is; At my skill level, it doesn’t make much difference at 100m. I intend to stretch the next batch out to 300. That,IMO, will tell a better story.

[JeffreyDeGraff]

So I loaded up 6ea. Adjusting micrometer for each round to achieve an identical measurement to the ojive and the others by setting the die for the first round and leaving it set for the other five.
Loading Barnes Match Burners groups were almost identical, only 2mm difference @100m.
Loading Sierra TMKs both groups measured out @ 9mm, with the ‘flyer’ opening up the group of individually set rounds by 2mm
My deduction based solely on this information is; At my skill level, it doesn’t make much difference at 100m. I intend to stretch the next batch out to 300. That,IMO, will tell a better story.

Keep it coming papajoe. I love these kinds of tests.


JTD