Seating depth ?

[Elkman]

A friend who is a beginning reloader asked me a question today, and I was not sure of the answer. How deep must a bullet be seated? I assume for single loading there is a more latitude, but for a magazine rifle, is their a minimum requirement, or industry standard. This is assuming magazine length is not a factor. Thanks all for the help. !!!!

 

[HeathSexton]

I have read caliber depth, .30 cal bullet seat .308" deep minimum.

 

[Oldtrader3]

I also try to seat bullets to about one caliber length into the neck of my cases. Or if that does not work, I use the Nosler manual for recommended COAL.

 

[Alderman]

There is an industry standard for OAL, but isn't always followed nor required depending on the application.

 

[jimbires]

I don't know where I read it , but I always thought one caliber was it . the only thing I can find in print is from Barnes bullets . they recommend 2/3 caliber minimum .

 

[Elkman]

Thanks guys, that is what I had thought but was hesitant to tell him that until I got some confirmation. Thanks for the help!

 

[Oldtrader3]

I would suggest doing a 30 bullet sampling of different seating depths each, starting with (30) 1/2 bullet diameter samples and another group with maximum of one bullet diameter for another (30) samples. Firstly, take these two sample groups and measure Total Indicated Runout (TIR) of each cartridge in both groups of (30) samples, measured at tangent point of shoulder on each bullet with a gauge block and dial indicator.

Analysis of variance (ANOVA) on the measured TIR of each sample cartridge within the two groups. Shoot all (60) samples and measure group size. This should be a high correlation predictor of group size between the two groups. This analysis will at the very least, tell you how high the correlation predictor is between COAL TIR and actual group size.

 

[Vince]

I usually talk with the bullet maker, or look in the bullet manufacturer's manual, and start at the suggested COAL. From there, after finding my most accurate powder charge, I'll adjust the seating depth.

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[Oldtrader3]

Vince, my problem is that this type of information they will tell me and reality are often not the same! For instance: 1/2 diameter minimum seating depth gives you what, in terms of accracy?

 

[Vince]

Vince, my problem is that this type of information they will tell me and reality are often not the same! For instance: 1/2 diameter minimum seating depth gives you what, in terms of accracy?

I've had pretty good results finding acceptable, if not outstanding, loads this way.
It's a simple way that doesn't delve in to the depths of handloading but I'm OK with that as I'm a pretty simple guy that doesn't deal well with intricate stuff.

Vince

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[Oldtrader3]

No issue, what ever works for you, Vince? I probably get overly technical sometimes?

 

[Vince]

No issue, what ever works for you, Vince? I probably get overly technical sometimes?

Thanks mate.
I didn't think it was an issue. I just do what I've learned, which would fit in a thimble btw, and keep from blowing myself up.

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