Howdy: Exactly how critical is seating depth when I have a .18 inch jump to the lands if I seat the bullet one caliber lenght into the case neck, and really not enough bullet into the neck when I try to seat the bullet to be .01 inch from the lands. On my 7x57mm Mauser using a 162 gr. Hornady boattail, the overall cartridge lenght is 3.262 inches. I have plenty of magazine lenght in my CZ550 American, but the bullet just ain't long enough. None the less, I seat the bullet to where there's about a .005 ribbon of clear copper showing below the canlures, which gives me an overall cartridge lenght of 3.090 inches. This is a good load for me. However, just for the heck of it, I loaded some that were 3.15 inches overall length with the same load of 48.3 grains of H414 and the accuracy level stayed about the same. So, the question is again, when you have a substantial jump to the lands in the first place, is bullet seating depth still all-critical? Thanks people ... Tom Purdom

Tom. Sounds like your rifle has the long throat used for 175 gr. bullets. I have a Winchester Model 70 Featherweight that is quite temperamental with the shorter bullets as well.
To answer your question though, I would imagine that the seating distance would still be "all critical."
I don't know how much help this will be, but the 139 gr. Hornady, shotgun patterns, 140 gr. Sierra spitzer flat base, 1.0 inch groups, Sierra 140 gr. boattail, shotgun patterns, 140 gr. Nosler Ballistic tips, a disaster, 154 gr. Hornady SPFB, shotgun patterns. 150 gr. Win. Power points, erratic as hell, 175 gr. Hornady SPFB, very wide shotgun patterns and the 175 gr. Hornady .75 inch. Winchester factory 145 gr. Power points 1.5 inches used as a control.
All the bullets were seated as close to the lands as I could get them, and still maintain cartridge integrity.
Probably wasn't a hell of a lot of help here, but that's how my rifle works with various bullets. 7x57's can be a challenge.
Paul B.

[This message has been edited by Paul B (edited 02-24-2002).]

Bullets do not have to be seated into the lands to shoot good. Find your max. OAL that will work in the magazine, chamber. Find the shortes OAL with the bullet base at the junction of the neck, shoulder area with a flat base bullet, a boattail seat to junction with fullest dia. of bullet. This gives you min. an max. OAL. Now find 2 different OAL in between the min. max. Load 5 rounds of each OAL ( should have 4 different OAL) Fire for group. Remember is with every thing else being the same, powder , primer, brass, ect.

Remember each gun is a world unto itself. It might matter and might not. You just have to try it and see. "D"

243winxb,
In that absence of any other plan, I will use yours in my new Addams and Bennnet 243 barrel blank chambered to just close on my resized brass.

I have 56 pieces of brass and three powders:
IMR4350
IMR4895
H414

[3 powders] X [4 OAL] = 12 loads

[56 pieces of brass] / [12 loads]= 4.7 rounds per group

Maybe I will drop one load for 5 shot groups

I too found that problem in 7X57s, I did have very good luck shooting 175gn Horns & 160gn RN Sierra's.

I tend to prefer a minimum jump between bullet and lands, but the existence of some "freebore" is not necessarily problematic for accuracy. After all, the entire Weatherby line depends on freebore to effectively increase chamber capacity, and many, though not all, Weatherby rifles are quite accurate.

I think that a change in seating depth still has, or can have, and effect on accuracy due to changing the point at which the bullet exits the muzzle during the harmonic vibrations. This would be regardless of whether you have a short or long throat.

If your rifle happens to have a very long throat, just play with seating depth a little and you might find a "sweet spot" even though you are still quite a bit short of the lands.