Seating on the lands.

mrawesome22 · January 11, 2007, 04:55 PM

I know there is a big debate about wheather or not this practice raises pressure signifigantly. I was just wanting you guys' opinions. I've never done it before and wanted to try it just to see what happens. I've ordered a glass bed kit and floated the barrel on my 700VLS and I'm just generally tinkering with it and thought maybe loading on the lands might give me something else to do. Is this dangerous? Should I start with a powder charge that is known to be safe at .030" off the lands, or do I need to work up all over again? Thanks Guys

Buckythebrewer · January 11, 2007, 05:27 PM

Were it really matters is when your loads are already near overpressure.If there already border line,Seating into the rifling can raise pressures way to high because there is no jump to ease things along..I would just maybe back off some(on powder) when you try it,just to be on the safe side.I seat into the lands all the time in my ar15 without issues or signs of overpressure but my loads are well under max usually..The funny thing is ,Ive seen more accuracy from allowing it to jump .005-.015 (being FL sized)off the lands..
It is regular practice to JAM into the rifling as long as your charges are not to high..This is stuff Ive read in the manuals as well as tried myself,maybe there are conditions that ive not come across to look out for,,But for the most part I would think just backing off powder charges and working back up would be fine.

castnblast · January 11, 2007, 06:54 PM

Mr. A, I tried it w/ my 22-250, and litterally saw no diffence in the pattern. As the gun gets older, I was told that's when you start seeing a difference.

Bullet94 · January 11, 2007, 11:11 PM

You might check this out –

http://www.benchrest.com/forums/show...=seating+depth

http://www.benchrest.com/forums/showthread.php?t=34425

amamnn · January 11, 2007, 11:51 PM

Seating in the lands, or "jam seating" is not always going to increase accuracy in factory rifles for a variety of reasons, not the least being that over the last few years the rifle makers have been lengthening the leade (aka the throat [sic] ) of their rifles with the intent of preventing you from doing just that. Their reasons are self protective and not necessarily aimed at handloaders. The glut of foreign made ammo and military retired ammo on the market has made it incumbent upon the manufacturers to do this. Handloaders are a small fraction of the firearms buying public.

That being said, a number of handloaders have been experimenting with bullet seating and some have adopted a current benchrest fashion of jam seating. There really is no question that jam seating does increase start pressure. The tiny bit of gas expelled ahead of the bullet in conventional seating is not allowed to escape before the bullet seals the barrel. I've heard various numbers, but it seems like an increase of 8,000 psi in a typical .223 rem round is not unusual when jam seating is used. There is a difference in the pressure rating between an off the shelf Remington 700 and a custom made benchrest rifle.

As noted above, there are other variables and factors to be considered and addressed when going to jam seating. The majority of pepole reloading their cases for fun and saving money will not have the tools or knowlege to make jam seating truly effective.

The main benefit of lengthened seating is to get a controlled and uniform start pressure. For factory rifles, this might be done more cost effectively by applying a light crimp to the round or controlling neck tension by using the bushing type sizing dies.

Bullet94 · January 12, 2007, 12:27 AM

I agree with amamnn that seating into the lands is not for every rifle and maybe not for every reloader either.

If your rifles up to it and so are you seating into the lands can be done safely and sometimes will give the best groups. Some bullets don’t like the lands and do better off the lands. As far as pressure increases, if you start at Jam and work up, pressure should not be any more of a problem than working up a load off the lands. Either way if you see any signs of high pressure reduce your load. I believe that it is not a good idea to take a MAX load off the lands and then seat this MAX load into the lands.

mrawesome22 · January 12, 2007, 02:45 AM

Well I'm getting great accuracy now at .030" off the lands. I just wanted to try something new. You know, just for experience sake. And I don't want to jam seat, just lightly touch. I was thinking this would keep start pressures the same every time as neck tension would be taken out of the equation. I turned down the mandrel .001" on my collet die for more neck tension and I'm getting great results. And I don't want to crimp. Like I said, just trying to get this bugger shooting one holes LOL. Maybe I'll try it one of these days. Thanks so much guys.

Bullet94 · January 12, 2007, 03:17 AM

mrawesome22

If you have a chronograph and you try touching the lands. Please post your results here in regards to velocity off the lands to just touching.

mrawesome22 · January 12, 2007, 04:07 AM

Well I'm getting ready to undergo a bedding job on my VLS right as soon as the kit gets here from Midway so it might be a while. But when I try it, I'll post my results. I always use a chrono. Don't know how I ever did without one LOL.

Maybe I can get some pressure signs seating on the lands LOL. I'm at max Hodgdon listed charges (always a grain higher than my books) for every powder I've tried and I've never seen any signs of too much pressure. Flat primers is all I've ever got and those were remidied by switching to neck dies (had improper headspace, I was a noob LOL).

amamnn · January 12, 2007, 03:31 PM

You'd do better to check overpressure signs by measuring head diameter; it's a pretty straightforward yes or no measure. Any good reloading manual can tell you how.

Buckythebrewer · January 14, 2007, 02:59 PM

+1 for bullet94.My experience is sometimes(probably bullet construction)they don't like being jammed.I have seen best accuracy sometimes .005-.015 off the lands compared to just touching the rifling.I also agree with the pressure remarks about starting at slightly jammed and working up the powder..Taking a near hot load and then jamming it could be VERY BAD

I think it all depends on the combo(chamber,powder charge,bullets used,etc,etc).JMO

sanson · January 14, 2007, 03:15 PM

I'm having great groups(.223) with light loads just barely touching the rifling

Buckythebrewer · January 14, 2007, 05:04 PM

Sanson,I have had good results doing that also(with light loads).For some reason driving 77gr smk with more powder(still under never exceed loads)they like to be .005-.015 off the lands from my experience in my rifle and chamber

GO figure

January 11, 2007, 04:55 PM	#1
mrawesome22 Senior Member Join Date: November 9, 2005 Location: Ohio, Appalachia's foothills. Posts: 3,779	Seating on the lands. I know there is a big debate about wheather or not this practice raises pressure signifigantly. I was just wanting you guys' opinions. I've never done it before and wanted to try it just to see what happens. I've ordered a glass bed kit and floated the barrel on my 700VLS and I'm just generally tinkering with it and thought maybe loading on the lands might give me something else to do. Is this dangerous? Should I start with a powder charge that is known to be safe at .030" off the lands, or do I need to work up all over again? Thanks Guys

January 11, 2007, 05:27 PM	#2
Buckythebrewer Junior member Join Date: April 15, 2006 Location: Jefferson, ME Posts: 700	Were it really matters is when your loads are already near overpressure.If there already border line,Seating into the rifling can raise pressures way to high because there is no jump to ease things along..I would just maybe back off some(on powder) when you try it,just to be on the safe side.I seat into the lands all the time in my ar15 without issues or signs of overpressure but my loads are well under max usually..The funny thing is ,Ive seen more accuracy from allowing it to jump .005-.015 (being FL sized)off the lands.. It is regular practice to JAM into the rifling as long as your charges are not to high..This is stuff Ive read in the manuals as well as tried myself,maybe there are conditions that ive not come across to look out for,,But for the most part I would think just backing off powder charges and working back up would be fine.

January 11, 2007, 06:54 PM	#3
castnblast Senior Member Join Date: July 2, 2006 Location: Corpus Christi TX Posts: 1,148	Mr. A, I tried it w/ my 22-250, and litterally saw no diffence in the pattern. As the gun gets older, I was told that's when you start seeing a difference.

January 11, 2007, 11:11 PM	#4
Bullet94 Senior Member Join Date: September 8, 2004 Location: Kansas Posts: 723	You might check this out – http://www.benchrest.com/forums/show...=seating+depth http://www.benchrest.com/forums/showthread.php?t=34425

January 11, 2007, 11:51 PM	#5
amamnn Senior Member Join Date: May 13, 2006 Location: WA, the left armpit of the USA Posts: 1,323	Seating in the lands, or "jam seating" is not always going to increase accuracy in factory rifles for a variety of reasons, not the least being that over the last few years the rifle makers have been lengthening the leade (aka the throat [sic] ) of their rifles with the intent of preventing you from doing just that. Their reasons are self protective and not necessarily aimed at handloaders. The glut of foreign made ammo and military retired ammo on the market has made it incumbent upon the manufacturers to do this. Handloaders are a small fraction of the firearms buying public. That being said, a number of handloaders have been experimenting with bullet seating and some have adopted a current benchrest fashion of jam seating. There really is no question that jam seating does increase start pressure. The tiny bit of gas expelled ahead of the bullet in conventional seating is not allowed to escape before the bullet seals the barrel. I've heard various numbers, but it seems like an increase of 8,000 psi in a typical .223 rem round is not unusual when jam seating is used. There is a difference in the pressure rating between an off the shelf Remington 700 and a custom made benchrest rifle. As noted above, there are other variables and factors to be considered and addressed when going to jam seating. The majority of pepole reloading their cases for fun and saving money will not have the tools or knowlege to make jam seating truly effective. The main benefit of lengthened seating is to get a controlled and uniform start pressure. For factory rifles, this might be done more cost effectively by applying a light crimp to the round or controlling neck tension by using the bushing type sizing dies.

January 12, 2007, 12:27 AM	#6
Bullet94 Senior Member Join Date: September 8, 2004 Location: Kansas Posts: 723	I agree with amamnn that seating into the lands is not for every rifle and maybe not for every reloader either. If your rifles up to it and so are you seating into the lands can be done safely and sometimes will give the best groups. Some bullets don’t like the lands and do better off the lands. As far as pressure increases, if you start at Jam and work up, pressure should not be any more of a problem than working up a load off the lands. Either way if you see any signs of high pressure reduce your load. I believe that it is not a good idea to take a MAX load off the lands and then seat this MAX load into the lands.

January 12, 2007, 02:45 AM	#7
mrawesome22 Senior Member Join Date: November 9, 2005 Location: Ohio, Appalachia's foothills. Posts: 3,779	Well I'm getting great accuracy now at .030" off the lands. I just wanted to try something new. You know, just for experience sake. And I don't want to jam seat, just lightly touch. I was thinking this would keep start pressures the same every time as neck tension would be taken out of the equation. I turned down the mandrel .001" on my collet die for more neck tension and I'm getting great results. And I don't want to crimp. Like I said, just trying to get this bugger shooting one holes LOL. Maybe I'll try it one of these days. Thanks so much guys.

January 12, 2007, 03:17 AM	#8
Bullet94 Senior Member Join Date: September 8, 2004 Location: Kansas Posts: 723	mrawesome22 If you have a chronograph and you try touching the lands. Please post your results here in regards to velocity off the lands to just touching.

January 12, 2007, 04:07 AM	#9
mrawesome22 Senior Member Join Date: November 9, 2005 Location: Ohio, Appalachia's foothills. Posts: 3,779	Well I'm getting ready to undergo a bedding job on my VLS right as soon as the kit gets here from Midway so it might be a while. But when I try it, I'll post my results. I always use a chrono. Don't know how I ever did without one LOL. Maybe I can get some pressure signs seating on the lands LOL. I'm at max Hodgdon listed charges (always a grain higher than my books) for every powder I've tried and I've never seen any signs of too much pressure. Flat primers is all I've ever got and those were remidied by switching to neck dies (had improper headspace, I was a noob LOL).

January 12, 2007, 03:31 PM	#10
amamnn Senior Member Join Date: May 13, 2006 Location: WA, the left armpit of the USA Posts: 1,323	You'd do better to check overpressure signs by measuring head diameter; it's a pretty straightforward yes or no measure. Any good reloading manual can tell you how.

January 14, 2007, 02:59 PM	#11
Buckythebrewer Junior member Join Date: April 15, 2006 Location: Jefferson, ME Posts: 700	+1 for bullet94.My experience is sometimes(probably bullet construction)they don't like being jammed.I have seen best accuracy sometimes .005-.015 off the lands compared to just touching the rifling.I also agree with the pressure remarks about starting at slightly jammed and working up the powder..Taking a near hot load and then jamming it could be VERY BAD I think it all depends on the combo(chamber,powder charge,bullets used,etc,etc).JMO

January 14, 2007, 03:15 PM	#12
sanson Senior Member Join Date: December 21, 2006 Location: FL panhandle Posts: 547	I'm having great groups(.223) with light loads just barely touching the rifling

January 14, 2007, 05:04 PM	#13
Buckythebrewer Junior member Join Date: April 15, 2006 Location: Jefferson, ME Posts: 700	Sanson,I have had good results doing that also(with light loads).For some reason driving 77gr smk with more powder(still under never exceed loads)they like to be .005-.015 off the lands from my experience in my rifle and chamber GO figure