Is it true that seating out bullets so far that they are just barely touching the lands eliminates slight misalignment of the bullet axis to the bore and thus provides more consistant shot to shot accuracy?

Is it also true that seating out bullets this way barely increases pressure and is a safe thing to do?

Most of what I've read is that the bullets should be seated just off the lands and not touching. If there is too much pressure against the lands there will be more pressure build up before the bullet begins to move. If you can, in fact, have them touch ever so lightly consistently then what you say may be true in some instances. However, not all guns perform as well with the bullets close to the lands. Weatherby rifles are noted for having deep throats and the bullets are actually farther away from the lands than most other rifles, but many of them shoot very well. You just have to try and find out what works in your gun. My Ruger .243 is not picky at all about how close to the lands the bullets are. Anything within a reasonable distance shoots as well as those seated to just off the lands. We'll, that's my three cents worth.

if you work up you loads with the bullet jammed into the lands there should not be any issues with pressure.
control bullet grip,for target loads I shoot for .002" to .003" measure bullet grip by measuring the case neck before and after seating a bullet.
hunting loads and others especially heavy recoil calibers need more grip or in some case need crimped, if the bullet is not held firmly
they can seat them selfs deeper with recoil.
Dave

Where your bullet preferes to be seated depends on the rifle. Some like a bit of jump and others want the bullet touching. Touching isn`t the best choice for hunting loads though.

I usually work up my loads with the bullet touching the lands and after I find the max load start reducing the OAL in 0.005" steps until I find the OAL the rifle shoots best. This is normally about .010" off the lands but can be from touching to 0.1"+ in some rifles.
Working with the bullet touching while determining your max powder charge helps keep pressures down when later playing with the seating. Starting well off the lead and working into it "could" cause pressure to go up. Still keep a eye out for pressure changes when ever changing a load.

quote:

Originally posted by reindeer:
Is it true that seating out bullets so far that they are just barely touching the lands eliminates slight misalignment of the bullet axis to the bore and thus provides more consistant shot to shot accuracy?

If you had a misalignment, I can't imagine touching ONE end doing anything except tilting something or everything.

Only thing is to try different things and then prove it by doing it again and again. When I get an accurate rifle it seems to shoot about anything. With a dud I'm lucky to find any load acceptable.

quote:

Originally posted by Red C.:
Most of what I've read is that the bullets should be seated just off the lands and not touching. If there is too much pressure against the lands there will be more pressure build up before the bullet begins to move. If you can, in fact, have them touch ever so lightly consistently then what you say may be true in some instances. However, not all guns perform as well with the bullets close to the lands. Weatherby rifles are noted for having deep throats and the bullets are actually farther away from the lands than most other rifles, but many of them shoot very well. You just have to try and find out what works in your gun. My Ruger .243 is not picky at all about how close to the lands the bullets are. Anything within a reasonable distance shoots as well as those seated to just off the lands. We'll, that's my three cents worth.

I have heard the same thing about Weatherby rifles. The term is "freebore", for the distance the bullet can travel from the cartridge to where the sides of the bullet engage the rifling. Allows some buildup of extra velocity without too much pressure build-up.

This goes in opposition to the conventional wisdom that the bullet, when fully inserted in the chamber should just touch the rifling for best accuracy. The theory is that if there is great deal of freebore length (and especially if it is oversize) in front of a bullet, it has the opportunity to get tilted or lose its alignment with the bore. The alignment that the handloader so carefully maintained when loading the bullet in the cartridge.

You pays your money and takes your choice.

I have heard that many handloaders/benchrest shooters figure out the precise seating depth that will make the rifling leave marks on the bullet. Then seat .001" deeper. (You will of course have to trim your cases for length assiduously.)

In any case, load your cartridges the same way every time except for the powder, which you work up slowly from lighter to heavier until you get signs of too much pressure or achieve your goal, whichever comes first. If you load with your bullets seated deeper to creat a little freebore, work up your loads. Then, if you seat your bullets a little further our to just engage the rifling, lower your charge and work up your loads again. (I know, everybody knows this already, but there is always an exception or two.)
Good shooting and don't pinch your fingers in the press.

Lost Sheep (Larry)

Larry,
Thanks for the remeinder

quote:

Originally posted by JAL:
If you had a misalignment, I can't imagine touching ONE end doing anything except tilting something or everything.

Unless you have a super-tight neck condition or the bullet is really jammed into the lands, things will alway be "out of alignment."

Let's say there is 0.001" clearance between the cartridge case and the chamber walls. Gravity will cause the cartridge to sit on the bottom of the chamber. You are now 0.001" out of alignment!

My thinking is that the bullet tends to self-center when it obturates. I do like to be as close to the lands as possible and kissing them is not a bad thing if the COAL works.

All true, but, Doesn't explain how so many Factory (loose fit) and long free-bore (factory and handloads), shoot so well.

I've had factory rounds so good I've pulled them, to see what magic they used. Heck, they couldn't even get the powder weight exact.

quote:

I have heard the same thing about Weatherby rifles. The term is "freebore", for the distance the bullet can travel from the cartridge to where the sides of the bullet engage the rifling. Allows some buildup of extra velocity without too much pressure build-up

interior ballistics are changed from one cartrage design to another, With the weatherby case design long taper, long sholder,compared to an ackley with a streight design short sholder taper..
the standard cartrage in general is designed around 40 to 60k the weatherby mags around 60 to 80K big diffrence in the working pressures and where the pressure curve is generated.

Unless you have a super-tight neck condition or the bullet is really jammed into the lands, things will alway be "out of alignment."