bullet seating depth

[double g]

does seating bullet below neck hurt accuracy and what is the minium seating depth that should be used to hold the bullet.

 

[Leaddog]

Bump for an excellent question.

 

[300 RUM]

You have to imagine the bullet bearing surface and then picture the center of it. The center line should not be below the center line of the neck. You can look for an accuracy node with the bullet seated beyond the neck center line but not behind it. Did that make sense to you?

 

[fredhorace77]

i have always heard that the bullet needs to at least be seated 1/8th,(.125) inch into the case at least. anyone else have anything to the contrary or to support this claim?

 

[double g]

The centerline basics makes sense, I dont like the bearing surface to be below the neck. I have had the bullet seated out with only about .100 holding it, but I dont really like it, but it seemed to shoot ok.

 

[necchi]

I don't think it's as easy as an absolute answer,
Can you seat the bullet below the neck? Sure, too far and your changing case capacity/volume issues and pressures can change.

What's the minimum? Well IMHO it's what ever it takes to hold the bullet reasonably concentric with the case and chamber neck/throat.
Issues of bullet grip (another variable) arise when playing with seating in or not so in the neck like that.

I pay attention to where the bullet is in the neck, but I don't use that as a variable. More so it's the result of my adjusting the jump the bullet has to the rifling, know what I mean?
The bullet/case neck relationship isn't the focus, the jump or jam for some is the issue. I try to maintain at least the minimum that fredhorace77 mentions but only because it helps me keep the bullet straight.
Concentricity is a key issue especially with large chambered factory guns.

 

[Scott Harris]

I've read many times not to seat the bullet bearing surface below the neck-shoulder junction to avoid ill effects from donuts. Donuts can cause inconsistent neck tension and seating above them eliminates this issue. Beyond that, the bullet encroaches on the case volume when seated deeply, but that is not an accuracy issue per se...just a velocity issue.

 

[nastynatesfish]

I start loads at book OAL but when I use light for case bullets like a 35gr 224 bullet or the 55gr 243 bullets I use a caliber length in the case. Measure trimmed case length add to bullet length, subtract bullet diameter and use that for OAL. Just how I do it. If you use long bullets then I don't see any reason to have the bullet seated to the ogive in the case. I use 162 AMAX in my r em mag and they are proabally 30thousands out. Same with the Berger that I've used