How shallow in the neck would you seat a bullet ?

I had an Axis 223 for several years,and it was always accurate with a variety of bullets that I shot throughout the years.I traded it off a little while back,and ordered me one of those Henry single shots chambered for 223/5.56..I have a variety of ammo laying around from my old one,and I thought I woud use it up,and I was less than satisified with accuracy.I then figured I would load some up for it,and have discovered that it has a LOT of free bore,and some really tapered bullets such as Hornady 55gr spire points,and 52gr hp match that I have on hand wont reach the lands unless they are seated real shallow.Bullets such as Sierra 63 gr SMP,and Winchester 64 gr.PP,and Speer 70 gr reach the lands but they really stick out.I think this may be a benifit on the heavier ones,because it will free up a little case capacity,but I dont know if I should even fool with the lighter ones.Have any of you ever ran into such issues?,and what is your opinion on the matter?

Gotta let the rifle tell you if it matters. Generally speaking the old time thought was at least one caliber in depth.
Personally I'm not afraid of jump, and will seat out as far as accuracy needs; and firmly held bullets can be done.

I almost get,but not quite the diameter of my bullet seated in the neck if I am just touching the lands with the 52 gr.,but almost nothing with the 55gr spire points.The 70 gr. Speers look good,and so do the Sierra 63 gr..I am surprised by the Winchester 64gr Power Points.They are designed funny,or I have a bad batch.I had never used them,but Midway had a deal on them,and I bought some.They look like they have a long bearing surface,but they don't reach full diameter till just a hair above the base.You can't even tell until you measure one.

Yeah depending on which, the 52 vmax is a long bugger.
http://www.jbmballistics.com/ballist.../lengths.shtml

I can get full bullet bearing into the case neck on just about everything except a .223 53gr Vmax...that one has maybe 80% contact at the OAL I want. I don't see why it would technically matter how much contact you get as long as the round is held in place and has consistent tension.

The worst case comes with lighter bullets with seating depth concerns because the bullet bodies are comparatively short. As you note, you should have no problems with the bullets above 60 grains.

I just did a quick comparison of bullets I had in my stash that shoot the most accurately in my 1:9 twist .223.
52 gr SMK #1410 has 0.30 bullet body (the goat tail reduces the amount of bullet body than can touch the neck or the rifling). Overall length is 0.697
52 gr Berger flat base #22408 has 0.35 bullet body with overall length of 0.724
53 gr SMK #1400 flat base has 0.4 bullet body with overall length of 0.711.

The SAAMI trim recommendation is 1.750.
The SAAMI O.A.L recommendation is 2.250.
If you start with SAAMI recommended O.A.L:
The 52 SMK BTHP would have .197 in the neck.
The 53 SMK flat base would have 0.211 in the neck.
The 53 Berger flat base would have 0.224 in the neck.
Berger suggests 2.260 so that would leave 0.214 in the neck.

I have had very good success with 52 SMKs seated out past 2.270 that left only 0.177 in the neck. I've even seated them out at 2.290 with only 0.157 in the neck and they shot accurately.

Based on my experience I would think that anything more than 67% of the bullet diameter in the neck would provide an adequate amount of consistency with neck tension to get good results.
That is assuming that your brass necks aren't too stiff and in need of annealing since that might effect the consistency of neck tension.

You have less to bullet body to play with if you use 50, 40 or even 35 grain bullets.
The bullets from 69 to 77 grains have plenty of bullet body and will just about always have enough bullet in the neck.

I just got done loading some of the 64gr PowerPoints,and I am going to try them when I can.I seated them at 2.34 OAL,and this puts me right on the lands with about .224 in the neck..I worked some up with charges of CFE223 ranging from 24.5-26.5..