If you are among those reloaders who choose to seat there cartridges OAL “hard into the lands” does that really mean resting on the lands or is it really off the lands by some thousandths. If it is really resting on the lands how do you deal with hard bolt closure?

Hey belle's dad, Here is "my" definition using numerical values to help.

Kiss-the-Lands: The bullet is Seated so the Ogive just makes contact with the Lands.

Lets say I take one specific bullet out of a box and measure the distance required so the Ogive just touches the Lands and get the Overall Cartridge Length(OCL).

Then I take that same exact bullet and Seat it in a case to the previous OCL and set the jam-nut on the Seating Stem. Then I remove the Seating Die from the press and measure the Overall Die Length(from the bottom to the top of the Seating Stem).

Lets say the OCL was 2.750" to Kiss-the-Lands and converted to ODL we might find it to be 3.850".

Now, anytime I want a bullet(from that exact box) Seated to just Kiss-the-Lands, I set the ODL to 3.850" and they will be right on the money.

Now, if I want the bullet Seated Into-the-Lands then I set the ODL to 3.860" and the Bullet will be Seated so that it is Into-the-Lands 0.010".

Likewise with an ODL of 3.825", the bullets are Seated 0.025" Off-the-Lands.

...

Recheck the Seating depth each time you open a new box of bullets. Occasionally the actual Ogive dimension varies slightly and you also need to compensate for Throat Errosion.

...

If you are only Seating 0.010" Into-the-Lands, then your Bolt action should close on it with enough resistance so you notice it, but not enough to cause you a problem.

How does this help accuracy ???????will it not cause excess pressure to build up and what are the gains. Just curious, Thanks

Hey SEALDOGGY, It helps accuracy "in some firearms" because the bullet centers itself in the bore prior to the ignition. Therefore it is not having to force itself straight into the barrel upon firing.

Granted, some firearms do prefer the bullet to get a running start. I've got one particular rifle that prefers a specific bullet seated 0.268" Off-the-Lands.

Concerning the Pressure build up, I agree. It is important to do the Kiss-the-Lands or Into-the-Lands with Starting Loads and increase the powder only if the Pressure Indicators say it is OK to do so.

For example, in another thread you had asked about a Load to use with the 168gr MatchKings in your 308Win. I'd responded to try the beginning Loads listed in the Hodgdon Manual with H380. I had a 26" Bull Barrel M700VL that with the 168gr MatchKings "seated to Kiss-the-Lands" would cut 3s all day when my concentration was up. No pressure indications were shown.

But, you always have to see what it does in your own rifle. My bullets are Moly Coated and my primers are probably different than yours. My cases are different as well as the chamber and bore dimensions. So, I agree with your question concerning the possibility of increasing the Pressure.

But, all the other factors must be taken into account as well. In some situations these other factors may raise the Pressure too. That is why it is the sign of a Rookie to duplicate someone else's Load without working up to it in your own firearm.

Good luck to both of you in your Load Development.

Thanks for clearing that up Hot Core. I can see clearly now by your example. Do you often seat to kiss the lands or into the lands? Myself I'm about .010 off the lands but since this is high volume varmint reloading I may stay there to be on the safe side.

Hey belle's dad, I dislike having to say this, but it just depends on the particular rifle and what I'm doing with it.

In the M700VL(mentioned above) I Seated the MatchKings to just Kiss-the-Lands. But,when I used Hornady Match bullets, they seemed to do a bit better Seated 0.010" Into-the-Lands.

I did hunt with that same rifle a few times from permanent Tree Stands. As I think back, I'm pretty sure I was using a 165gr Rem PSP with the same H380 load, but the bullets were(I think) 0.025" Off-the-Lands. This particular Lot of Rem PSPs provided excellent accuracy for a very inexpensive bullet. I think they ran in the 6s-8s for 3-shot groups when my concentration was up.

Most all of my rifles get to go hunting and I typically Seat the bullets some amount Off-the-Lands. First I find where the Harmonics converge using the Creighton Audette Method of Load Development. Then I fine tune the Load by reshooting groups while varying the Seating Depth. And I let that tell me where that specific Lot of bullets should be Seated for the best results with them.

So, basically there is no one Seating depth I use. I just let the firearm indicate what shoots the best in it and go with that.

Needless to say, it is EXTREMELY important to keep good accurate Records, that don't get lost or misplaced(voice of experience), on your Load Development process so you can duplicate the accurate Loads.

Just don't get in a hurry and you will do fine.

By the way, the reason you want to convert from OCL to ODL is because of the "Bullet Length variation".

This is easy to see for yourself by opening a box of bullets and measuring the actual lengths of 25-up bullets with a 0.001" capable Caliper. Just line them up across a table from the shortest to the longest and you will see a considerable difference.

The vast majority of this variation is found from the point on the Ogive that will touch the Lands forward to the tip. And from that same point on the Ogive back to the Bullet Base is very consistent.

So, when you convert that "one specific Bullet" from OCL to ODL, you eliminate the portion of the bullet where the variation is occurring.

If you go in and measure the OCL on a group of Loaded cartridges, you might get the impression something is wrong with your Seating because of the differences in Length. So,stick with ODL and forget about OCL at that point "until" you open a new box of Bullets.

[ 04-18-2003, 16:36: Message edited by: Hot Core ]