seating depth

[velvetant]

When you're shooting a short bullet and you have a long magazine and a long throat where do you start your OAL?
Do you seat them to the manufacture recommended OAL? Do you seat them out as far as possible?
Or do you seat to one caliber length?

My 243 for example: Barnes 85gr TSX manufacture recommended OAL is 2.645"
I can seat them out to 2.850" for my magazine and will have apx. .220" seated in the case and still have a .050" jump.
That is where I tested a few loads and they did alright.
Would you leave it there or do something different?
Randy

 

[RiverRider]

Randy, seating depth is one of my pet obsessions. I have a few rifles myself that are a bit long-throated. On one or two of them I can't get even the longest bullets to touch the leade, but I have found that this doesn't mean I can't get the.m to shoot.

Once upon a time I would not even use a comparator. Too many guys were promoting them as being a deadnutz measurement that represented the rifle's throat, and they most assuredly are NOT. But---one thing they do provide is consistency.

I have always relied on the split-neck case method to determine just where the lands begin with any given bullet, but now I measure those results with the Stoney Point (now Hornady) comparator. For some reason I cannot explain or defend, this seems to work better.

When I can't get near the lands, I'll generally just seat to some arbitrary length that gets about one caliber of the bullet's shank into the case neck. I'll measure using a comparator and make note of the comparator length. Usually the first time out with a new-to-me rifle is just an exercise to find where the charge limits might be, but I also pay attention to accuracy---even though I don't expect any at that point---and if one of the reasonable charges appears to want to shoot, I'll use it and vary seating depth as measured with the comparator. I never have any idea just how close I am to the lands, but that's no concern for me.

Seating right up against the lands just ain't necessary, but consistency is. I do, however, seat everything within .040" of the lands when I can tell where they are.