OK,..this could be a long one.

what have you found to be the "most occuring" feature with reguards to accuracy for different types of bullets? Lets say for example,..you find that a nosler BT in your testing works better at .001-.003" in the lands while a sierra MK works better in your tests at .010-.025" off the lands. I'm not asking for a law of the universe,..rather I am interested to see if a trend developes for for certain brands/designs of bullets, which may help to expediate the work-up process (taking into account there are always exceptions).

Based on my 30 plus years of reloading I have found that "most" of the time on the lands to .015" off the lands has provided me the best accuracy.

Most 100 & 200 yard bench rest shooters I know like their bullets on or real close to the lands. Then again, bench rest shooters use custom made rifles specific to obtaining every .001" of accuracy they can get on target.

You may want to check, if you have the means, the distance from the base of the bullets you're using to the start of the ogive. You may find that this distance varies by more then what you think. In that case are all of those loaded rounds really .001" to .003" off the lands?

Don

If there is a universal best I am not sure of it. I suppose .015" is a good place to start as any.

Seating into the lands can cause trouble in a hunting rifle. Most of the time this will mean that the loaded round is too long for the magazine. In a single shot rifle it could mean hard chambering or a stuck round or bullet in any action.

I just discovered that a 264WM will shoot only with a particular Lapua bullet seated hard into the lands. I know darn well that I should bed this action and maybe the barrel the right way but it's a lot of work so I am still playing around with it. This is not the best way to go about things.

Hey JustC, First off, I agree with both of the above.

This thread may not be as long as you think though, because most folks find a distance Off-the-Lands a particular bullet likes, they set up their Dies to Seat it there and then they forget about it.

Those same folks seem to forget the distance to the Lands is constantly changing. You can verify this for yourself by taking a single bullet and using it to measure the Kiss-the-Lands distance. Write the distance down and save it with that exact same bullet by leaving all of it in with your Dies. Then when you want to see how far the throat has receeded, remeasure with that bullet.

One of the things I recommend is that anytime you open a new box of bullets, you need to take one of them and verify the Kiss-the-Lands distance. As the throat lengthens, adjustments will need to be made in your Seating Depth to compensate for it.

The other problem this brings up is if you simply lengthen the Seating Depth, that changes the internal case volume and thus the "effective" Chamber Volume. Most of the time, the old Load doesn't need much tweaking, but if you are using a Magnum size case, slight Load changes may be needed after only one box of bullets. That is also very dependant on how many shots you send through the barrel when it is warm.

...

Some of my most accurate rifles prefer the bullets Seated Into the Lands. But, my hunting rifles all get the bullets Seated Off the lands. No particular distance, because as I mentioned above, it varies with each rifle and in how much a particuler rifle is shot. Some prefer 0.010" OTL and I have one that likes 0.264" OTL with one specific bullet.

As you can see, it is possible to go way overboard on this, or to any amount of measuring you so desire. In some of my firearms(like the 444Mar rifle, 357Mag revolver, etc.), I simply Seat to the Cannelure and never give it a second thought. At the distance I shoot this class of firearms, as long as the completed cartridge cycles properly, any accuracy adjustments I make to them do not include varying the Seating Depth.

[ 09-26-2003, 17:38: Message edited by: Hot Core ]

I normaly take a spilt case and use that toget a measurement that allows me to start at the lands. I will work up the powder charge that performs best,..and have now begun to play with the seating.

I have been told by sierra, every caliber except 22 should be at the lands and the 22 should be ~.010-.020" off.

I have read books that the author states conventional bullets need to be at or in the lands and that VLD's need to be at or just off the lands. I figured this was a rifle to rifle basis,..but out of curiosity, I am asking the members to share their experiences. This is simply something I have wanted to ask.

Hot Core,..how far into the lands do you usually experiment with on a new rifle to see if that is where they want to be? Let's say this is day one of your new load workup with a new gun,..do you seat them .005" ITL or some other preset (from past experience) distance? thanks.

[ 09-26-2003, 17:39: Message edited by: JustC ]

I start .015" into the lands, find the MV range for bullet wt. that shoots best, adjust with different primers, maybe powders for best ignition and consistancy, varying powder charge to stay in the MV range (sweet spot), them move to OAL to fine tune and see if it helps any.

I have noticed no trend as of yet, depends on the gun, sometimes makes no difference, other times alters it significantly. Worth fine tuning with it tho, IMHO.

Hot Core,

Have a question I been meaning to ask you about. I'll start another thread to keep this one on track. P-FLR is what I'll title it. Just a quick question as to your experience with it over several loadings as brass gets harder.

What differences do you guys see with reguards to pressure when you are at .010-.015" into the lands vs at the lands?

also,..will me having .002" neck tension securely hold the bullet when closing the bolt on a round set for .010-.015" ITL?

Thanks Brent and Hot Core

[ 09-29-2003, 19:43: Message edited by: JustC ]

JustC,
What's important to remember is the reason for seating at, near, or into the lands. Hot Core touched on it. When a bullet is seated into the lands, you know the ogive is aligned with the axis of the bore. When the bullet jumps to the lands and runout is present, the bullet will not not be entering the bore straight. This can slightly deform the bullet as it is "swaged" into the throat, and cause all kinds of problems with accuracy.

I seat bullets hard into the lands with my 20BR, but I'm also expecting groups to be consistently in the .3's at worst. In rifles used for deer hunting, off the lands is definitely better. You may have to eject a loaded round from the chamber and you don't want the bullet stuck in the lands and powder scattered throughout your action. I seat bullets for my 7-08AI about .010" off the lands, but my dad's factory 7mm-08 Model 7 shoots better at least .015" off the lands.

As interesting as this post is, our tinkering is all for naught if the chamber is oversized or otherwise sloppy. If we start with a case that has no runout and no bullet runout (our "perfect" case) and seat into the lands, it is still possible that the only thing lined up with the axis of the bore is the ogive of the bullet. The axis of the entire cartridge, including the bullet, may still be off bore line. Hence, good chambers matter. I almost didn't post this because I didn't want to rain on anybody's parade, but that is why benchrest competition may see only a few thousandths between first and worst.

If the rest of the cartridge is crooked, or fits loosely in the chamber, running the bullet into the lands may only mean that you've already started it into the bore crooked before firing. If everything else is aligned well, the bullet can get a straight start even if it has a little bit of "freebore" before the lands. Lots of rifles (Weatherbys, for example) shoot very nicely even when the bullet has to move 3/8" before contacting the rifling.

NotRicochet,
That's pretty much what I was trying to say. I guess it didn't come out very well.

No, I think you pointed out the problems very well. I only wanted to emphasize that having the bullet jammed into the lands still doesn't guarantee that it's starting straight. It can be jammed in at an angle from the start.

OK gentlemen,...I see your point with reguards to factory chambers, and hunting rounds. maybe a .005-.015" OTL would be the practical approach.

Now,..lets say in my custom chambers,..would the ITL approach be a good start for the VLD type bullets such as the a-max, clinch river, JLK, cartaruccio, match king, berger, etc. I have some verticle at 1000yds in my 300RUM and so far I have only seated AT the land. I am figuring this verticle is a pressure/velocity variation and therefore I am trying to gain some insight to change the seating.

Thanks