Thread: 6.5x55 seating depth

Originally Posted by chalkeye

OAL is the total length of the loaded cartridge (base of brass to tip of projectile).
SAAMI standard length for 6.5x55 is 80mm, but if you're handloading you can seat bullets out to whatever length you want.
6.5x55 factory chambers typically have VERY long freebore / distance to lands (due to being chambered for round nose 150gr projectiles, which aren't particularly fashionable any more).

Lands are where the rifling starts in the chamber. If you seat a bullet longer than the lands, it will crush back into the case when you close the bolt.
"Couple thou off the lands" (0.5mm) is a common starting freebore for nerds that care a lot about that.
You will generally struggle to get that close to the lands with modern projectiles (which are pointier) and a factory chamber (which has a huge distance to lands). Having a large "jump" (distance to lands) doesn't seem to affect me that much, most factory swedes seem to shoot well enough without it being an issue.

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Correct me if I'm wrong here, but isn't it important to measure to the ogive when working out all these measurements? I know lead tipped pills vary drastically in length, even a lot of the lengths of ELDs I've measured aren't exactly that consistent. @chalkeye do you mean 20 thou? The average reloader will struggle to do anything down to 2 thou.

Originally Posted by McNotty

Correct me if I'm wrong here, but isn't it important to measure to the ogive when working out all these measurements? I know lead tipped pills vary drastically in length, even a lot of the lengths of ELDs I've measured aren't exactly that consistent. @chalkeye do you mean 20 thou? The average reloader will struggle to do anything down to 2 thou.

Yes. Measuring to the ogive is the ideal, but it is much easier to measure OAL, which means assuming a batch of projectiles are identical. Measuring to the ogive means each rifle has only one measurement for all projectiles, whereas OAL varies with projectile type and model.

Right you are @McNotty