How much (little) bullet can/should be in case neck?

[John Russell]

I have an older 220 Swift; re-measured jump recently after not using for years with a Hornady tool to check seating depth rifling engagement :

tool shows bullet hit lands @ 2.820" with a 52g Berger Varm Match bullet -- which places my bullet...out of the case.

So I loaded at 2.800", and tested as single shot load.
got a terrific (best) group, but the bullet is only .100" into case neck . Good tension .003"

I'm inclined to load em'. I usually like a/the bullet seated about halfway down neck...

thoughts?

View attachment 1039780

I load my .220 Swift to 2.90" with 53 tipped Varmageddons, which has them in the case about 0.080"... with no problems.

 

[CT10ring]

243winxb
That is just what happens when the pressure is to low starting due to not enough bullet in the case or to low a charge. The case doesn't seal the chamber and the pressure collapses the case. At least that is what was begining to happen to me in my 7/08.

great info, thx. My first 5 fired cases w 220 swift had soot halfway down - odd & not good. I assumed that I oversized a few cases ?
Next 10 were clean. with good groups.

 

[CT10ring]

I load my .220 Swift to 2.90" with 53 tipped Varmageddons, which has them in the case about 0.080"... with no problems.

great intel, thx. I was hoping to hear this "good news", validation, information...

 

[243winxb]

Here is where the photo came from, with info. https://thefiringline.com/forums/showthread.php?p=4928827#post4928827

 

[jepp2]

thoughts?

I had always used the guidance of 1/2 the bullet diameter as the minimum bullet seating depth (and you can't count the taper portion of a BT bullet). But I was shooting my 204 Ruger (which typically have 0.100" freebore) with CCI 450 primers and WC844 powder (bulk pulldown version of H335) and I had a primer go but not ignite the powder charge. The primer discharge seated the bullet into the lands. So for the .204 diameter bullets I now shoot for 0.200" seating depth.

 

[nmkid]

I have an older 220 Swift; re-measured jump recently after not using for years with a Hornady tool to check seating depth rifling engagement :

tool shows bullet hit lands @ 2.820" with a 52g Berger Varm Match bullet -- which places my bullet...out of the case.

So I loaded at 2.800", and tested as single shot load.
got a terrific (best) group, but the bullet is only .100" into case neck . Good tension .003"

I'm inclined to load em'. I usually like a/the bullet seated about halfway down neck...

thoughts?

View attachment 1039780

That's about where I load all my bullets and no problems. However, I do have the boattail sitting lower.

 

[rr2030]

I load my 22-250 with 55 FB Bergers seated .105" in the case, never an issue, just don't drop one.

 

[jds holler]

I've got a hair brained theory for everything. The one I like concerning case necks is "The less case neck, the less neck tension variance". jd