Just got a sako trg in 308 and found a case of nosler 155 customs. I am trying to develop a load and have read the stickys. I am trying to start with the bullet in the lands but I have been told not to seat the bullet any less than half the diameter (.150") of the bearing surface in the neck. With that set up I am still .050" away from the lands or jumping. The sticky says start .01 jammed which means I need to pull the bullet .06" further out only leaving around .09" of. Bearing surface in the neck. Is that enough? What is the minimum? Thanks for the help.
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Great question, I'll be watching this thread closely. I can't answer definitively, but I ran into a similar issue trying to develop a load with 155s for a Remington... at max magazine length they were .255 (yes! over a quarter inch) off the lands. Doing the math, the boat tail had cleared the case mouth before the ogive engaged the rifling. Those didn't group worth a damn obviously
I have read that bullet seating depth should be equal to the caliber of the bullet----.308's get .308" of the projectile in the case. I can't cite the source offhand, sorry. I would be VERY leary of going very much less than this, as you could conceivably have the bullet "cocked" in the neck, and try to enter the lands crooked, even severely so, which could cause big problems. Be sure what ever you do, you have good authority behind what you do.
I have also read several posts where it has been said that certain rifles cannot be loaded against the lands because of longer throats, etc. Also, read several articles where the author has tried jumps versus touching the lands, and says that there is very little difference in performance. A lot of conflicting info out there.
I have also read several posts where it has been said that certain rifles cannot be loaded against the lands because of longer throats, etc. Also, read several articles where the author has tried jumps versus touching the lands, and says that there is very little difference in performance. A lot of conflicting info out there.
I have room in the magazine I believe but want to make sure there is enough tension and Also surface to keep the bullet centered. I figure the less bearing surface in the neck the easier it will be to have the bullet not concentric. I am only using the 155 because that's all I could find I think, but can't verify that with the heavier and longer 175 I probably won't have this problem. But this is what I have to work with for a while.
I would love to find an article from someone with the proper knowledge like everyone so far I can't find a definitive answer. But for now I will stick with diameter minimum. I will break down my ladder test I had put together, bummer. Please keep the info coming if there is anything to add or if someone could post up a link where we can learn more.
There's no definite answer due to different manufacturers and weights will have different bearing surfaces. As long as you've got enough bite on the shank I would tune the load with whatever your rifle likes. The different typesor degrees of the ogives plays a roll. The vlds need jammed so there's less chance of yaw.
From Shooter's Forum:
Quote:
Originally Posted by 2433006300 View Post
The Problem With The 60 And 80 Grain Is Not Oal Because Even If You Only Seat Them .001 They Are Not Going To Be Too Long. What I Need To Know What Is The Least They Need To Seated Into The Neck. Do They Need To Go To Where The Neck Meets The Shoulder . Or Is 1/8 Of An Inch Ok.
Thanks Again
Rod
General rule of thumb is to seat your bullets at least one calibre deep; .243" into the neck of the case. I have gotten away with shallower seating, but you need to have a tight grip on the bullet to do this.
1/8" is a little shallow, but if you can't push the bullet in once seated by pushing the tip of the bullet against the edge of your loading bench, all's good!
The difference in COL probably won't make much difference to accuracy, as long as it feeds without moving in the case, you'll probably get good accuracy.
The reason that you don't shallow seat is to enhance accuracy by allowing the bullet to move a little more upon initial firing so that it reaches the lands with a bit of steam behind it, if it leaves the neck early, it can have enough time to tip before it engages the lands, which will ruin accuracy.
No. You only need them seated deeply enough that the bullet will not:
a) Be jammed into the throat, which raises pressure.
or
b) Won't come loose and fall out, with the exception described below.
Middleton Tompkins has more long range gold medals than anyone else, living or dead, as far as I know. At a clinic I attended he told us he sizes his case necks so the bullet slip in them under finger pressure. He seats them way out and lets their contact with the throat finish seating them as he closes the bolt. This technique requires you use a somewhat lower powder charge to compensate for the higher pressure throat contact causes. It has the drawback that if a cease-fire is called, you have to go to some trouble to unload the gun. The bullet usually sticks in the throat, so you must tip it muzzle-up first, then extract the case slowly or you will spill powder into your action. Then the bullet has to be knocked out of the throat with a cleaning rod.
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Nick
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From Reloader's Nest:
Alot of us have.
In all reality you only need the bullet a few thousands in the case,,But the trouble in doing so is refered to as Runout and Concentricity issues.
Neck tention or bullet grip is a variable thats dealt with here too.
The best accuracy is still obtained by keeping the case, the case neck and the bullet all in a straight line and parallel with the center of the bore.(Concentric) If the bullet is tipped a bit it'll leave the neck crooked, hit the lands an wobble a bit before straightening out or even go down the bore crooked, accuracy is trashed.
I shoot off the shelf guns too, long chamber necks and plenty of freebore, I have seated 308 bullets as little as .150 in the case trying to reach out too the lands and accuracy didn't improve (runout was that bad!)
Without a concentricity gauge (yup, another tool!) it's sometimes hard to see .006-.008 runout at the bullet tip, but you can roll a cartridge across a flat surface and watch the tip wobble.
It can be the case neck from sizing, It can be the bullet tipped in the neck when seating or both.
A local shop invited me to bring in some loaded rounds and run across their RCBS CaseMaster. We sorted the rounds in groups, some .006 out, plenty in the 003-4 range and some nice at .001. I went to the range and fired the sorted bullets.
I was amazed, you could see the rings around the bull made by the different groups, with the straight ones in the center.
Now I seat to sammi or near, find my best load then experiment moving them out .010-.100 looking for improvement. If it's good and I can keep reasonable concentricity then sobeit.
But my days of trying to crowd the lands with non-custom chambers are all but over, I mean I'll measure and look what it is, but I want straight ammo first.
The reason for the general rule of bullet diameter seating depth is to allow the bullet to align with the neck and presumably with the chamber. The further out you seat, the less self-alignment.
Sounds like your rifle's chamber has a long leade. I wouldn't be too concerned that you can't get as close to the lands as you would like.
It isn't necessary for accuracy in every rifle. I shoot a .204 Ruger and it's best accuracy is with a jump of .180" (.2" @ 100 yds). Couldn't touch the lands and still keep the bullet in the neck, anyway.
I'd start my OCW with a bullet diam. seating. Find your OCW and then tweak the depth by moving out .01 at a time. I think you'll find an accuracy node with plenty of bullet still in the neck.
So, I gather from all this that
A.) As long as you have adequate neck tension to keep the bullet from moving, you're good.
B.) Concentricity is more important than "jump" or lack there-of.
C.) you want to be sure that the bullets will feed in the magazine----not an issue with the lighter bullets which are shorter, and less likely to touch the lands anyway.
D.) you want to be sure that if you have to remove a chambered round that the bullet doesn't stay behind and cause your powder to spill.
E.) If you can meet all these criterion, then the actual amount of bullet in the neck is not that terribly important.
Having said all this, make sure that you are not touching or jammed in the lands with a high charge load----work up from low charge, to be sure that the pressure is okay with your rifle, as the less jump, especially touching or jammed may cause high pressures long before bullets at "standard" seating depths.
Quote:
Originally Posted by 2433006300 View Post
The Problem With The 60 And 80 Grain Is Not Oal Because Even If You Only Seat Them .001 They Are Not Going To Be Too Long. What I Need To Know What Is The Least They Need To Seated Into The Neck. Do They Need To Go To Where The Neck Meets The Shoulder . Or Is 1/8 Of An Inch Ok.
Thanks Again
Rod
General rule of thumb is to seat your bullets at least one calibre deep; .243" into the neck of the case. I have gotten away with shallower seating, but you need to have a tight grip on the bullet to do this.
1/8" is a little shallow, but if you can't push the bullet in once seated by pushing the tip of the bullet against the edge of your loading bench, all's good!
The difference in COL probably won't make much difference to accuracy, as long as it feeds without moving in the case, you'll probably get good accuracy.
The reason that you don't shallow seat is to enhance accuracy by allowing the bullet to move a little more upon initial firing so that it reaches the lands with a bit of steam behind it, if it leaves the neck early, it can have enough time to tip before it engages the lands, which will ruin accuracy.
No. You only need them seated deeply enough that the bullet will not:
a) Be jammed into the throat, which raises pressure.
or
b) Won't come loose and fall out, with the exception described below.
Middleton Tompkins has more long range gold medals than anyone else, living or dead, as far as I know. At a clinic I attended he told us he sizes his case necks so the bullet slip in them under finger pressure. He seats them way out and lets their contact with the throat finish seating them as he closes the bolt. This technique requires you use a somewhat lower powder charge to compensate for the higher pressure throat contact causes. It has the drawback that if a cease-fire is called, you have to go to some trouble to unload the gun. The bullet usually sticks in the throat, so you must tip it muzzle-up first, then extract the case slowly or you will spill powder into your action. Then the bullet has to be knocked out of the throat with a cleaning rod.
Share
__________________
Nick
__________________________
Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Instructor
NRA Patron Member
From Reloader's Nest:
Alot of us have.
In all reality you only need the bullet a few thousands in the case,,But the trouble in doing so is refered to as Runout and Concentricity issues.
Neck tention or bullet grip is a variable thats dealt with here too.
The best accuracy is still obtained by keeping the case, the case neck and the bullet all in a straight line and parallel with the center of the bore.(Concentric) If the bullet is tipped a bit it'll leave the neck crooked, hit the lands an wobble a bit before straightening out or even go down the bore crooked, accuracy is trashed.
I shoot off the shelf guns too, long chamber necks and plenty of freebore, I have seated 308 bullets as little as .150 in the case trying to reach out too the lands and accuracy didn't improve (runout was that bad!)
Without a concentricity gauge (yup, another tool!) it's sometimes hard to see .006-.008 runout at the bullet tip, but you can roll a cartridge across a flat surface and watch the tip wobble.
It can be the case neck from sizing, It can be the bullet tipped in the neck when seating or both.
A local shop invited me to bring in some loaded rounds and run across their RCBS CaseMaster. We sorted the rounds in groups, some .006 out, plenty in the 003-4 range and some nice at .001. I went to the range and fired the sorted bullets.
I was amazed, you could see the rings around the bull made by the different groups, with the straight ones in the center.
Now I seat to sammi or near, find my best load then experiment moving them out .010-.100 looking for improvement. If it's good and I can keep reasonable concentricity then sobeit.
But my days of trying to crowd the lands with non-custom chambers are all but over, I mean I'll measure and look what it is, but I want straight ammo first.
The reason for the general rule of bullet diameter seating depth is to allow the bullet to align with the neck and presumably with the chamber. The further out you seat, the less self-alignment.
Sounds like your rifle's chamber has a long leade. I wouldn't be too concerned that you can't get as close to the lands as you would like.
It isn't necessary for accuracy in every rifle. I shoot a .204 Ruger and it's best accuracy is with a jump of .180" (.2" @ 100 yds). Couldn't touch the lands and still keep the bullet in the neck, anyway.
I'd start my OCW with a bullet diam. seating. Find your OCW and then tweak the depth by moving out .01 at a time. I think you'll find an accuracy node with plenty of bullet still in the neck.
So, I gather from all this that
A.) As long as you have adequate neck tension to keep the bullet from moving, you're good.
B.) Concentricity is more important than "jump" or lack there-of.
C.) you want to be sure that the bullets will feed in the magazine----not an issue with the lighter bullets which are shorter, and less likely to touch the lands anyway.
D.) you want to be sure that if you have to remove a chambered round that the bullet doesn't stay behind and cause your powder to spill.
E.) If you can meet all these criterion, then the actual amount of bullet in the neck is not that terribly important.
Having said all this, make sure that you are not touching or jammed in the lands with a high charge load----work up from low charge, to be sure that the pressure is okay with your rifle, as the less jump, especially touching or jammed may cause high pressures long before bullets at "standard" seating depths.
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Thank you sniper uncle great info there! Really clears the issue up for me and explains why. Could you tell me what you entered in the search criteria to find that? I'm horrible at finding stuff searching and trying to learn. Thanks again for that info very helpful.
I just did a google search on minimum bullet seating depth, and waded through the responses. I quoted sections from other shooter forums. I think I referenced the forums in the post.
My rifle has the throat cut to shoot the 190gr Noslers. I'm currently shooting 155gr Noslers with .180 seating depth. Measured it last night just to see what it was. From my experience, the 155gr Noslers like to jump from .020" to .040", sometimes more. They didn't like touching the lands.
The only bullets that I've ever shot that liked touching the lands are the JLK's. Even the Berger VLD's shot better for me jumping. Berger used to have a good article about jumping bullets on their website, it might still be there.
The only bullets that I've ever shot that liked touching the lands are the JLK's. Even the Berger VLD's shot better for me jumping. Berger used to have a good article about jumping bullets on their website, it might still be there.
Just to piss gasoline on the fire:
I'm playing around with a 308 load that's showing a lot of potential... 155 SMK Palmas, FC cases, Varget. .080 jump, and provided that I weed out the crooked ones (concentricity gauge) they colverleaf at 100, .5moa at 200. I believe Sniper Uncle posted the article above citing concentricity as being so critical with big jumps... from just having shot some yesterday, I agree 100%
I'm playing around with a 308 load that's showing a lot of potential... 155 SMK Palmas, FC cases, Varget. .080 jump, and provided that I weed out the crooked ones (concentricity gauge) they colverleaf at 100, .5moa at 200. I believe Sniper Uncle posted the article above citing concentricity as being so critical with big jumps... from just having shot some yesterday, I agree 100%
As long as I can get them to shoot, not going to set the barrel back. I still have a supply of the 190's and they shoot great but since I have a supply of the 155's also, shooting them too. I have at least 1K of life before I set the barrel back.
Excellent info im going to seat my bullets in my ladder test so they are .30" in the case and go see what happens. Every thing I have put through the rifle so far has grouped consistently under 1moa which is plenty good for what I am doing right now but I always want more. I don't have a concentricity gauge yet but its on my list.
"What is the minimum?"
If your bullets fall out from normal handling you're not deep enough.
A lot of cartridges have necks less than one caliber long. They don't blow up and the bullets don't fall out.
The diameter of the chamber leade controls the maximum amount of bullet runout, not the dies or how far off the lands the bullet is.
Seating into the lands resists initial bullet movement; that accellerates the starting burn speed and jacks pressure WAY up unless the charge is reduced.
Few factory rifles shooting mass produced bullets shoot their best seated at or into the lands, most prefer from 20 thou off to as much as five times that much. Obviously there are exceptions to simplistic solutions but the biggest "accuracy" farce I know of is seating at or really near the lands. Well, that and how great neck sizing is supposed to be.
If your bullets fall out from normal handling you're not deep enough.
A lot of cartridges have necks less than one caliber long. They don't blow up and the bullets don't fall out.
The diameter of the chamber leade controls the maximum amount of bullet runout, not the dies or how far off the lands the bullet is.
Seating into the lands resists initial bullet movement; that accellerates the starting burn speed and jacks pressure WAY up unless the charge is reduced.
Few factory rifles shooting mass produced bullets shoot their best seated at or into the lands, most prefer from 20 thou off to as much as five times that much. Obviously there are exceptions to simplistic solutions but the biggest "accuracy" farce I know of is seating at or really near the lands. Well, that and how great neck sizing is supposed to be.
Strangely enough, many many of the most accurate loads are "jam" chambered, that is the bullet is touching, or into the L and G, without regard to the total seating depth. Many very successful Bench Rest shooters in fact- have their neck tension so low that they seat the bullet with finger pressure, leaving it very long, when the bolt goes forward, the bullet is pushed into the L and G, neck tension and jump are virtually eliminated, 10 rounds in the teens, is hard to argue with. Seating bullet in this fashion gives the shooter the closest possible repeatability (or so the theory, and often the practice goes). For repeaters, this practice is difficult, and unsafe at times, you're magazine will dictate the max OAL, and if you ever find yourself in a situation requiring to "make the line safe", chances are the bullet will stay in the barrel, and powder will be dumped from the case into your action. For those wanting to use "lighter" bullets, or more correctly "shorter" bullets, a discussion with your smith, and some dummy rounds will help him- help you in cutting your chamber.
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"Many very successful Bench Rest shooters in fact- have their neck tension so low that they seat the bullet with finger pressure, leaving it very long, when the bolt goes forward, the bullet is pushed into the L and G, neck tension and jump are virtually eliminated, 10 rounds in the teens, is hard to argue with."
You read a lot of gun magazines, right?
When you start shooting $5,000 single shot BR rifles with hand made bullets in precisely turned case necks with such low "tension" you can finger seat long and let your rifling finish the job you should do it that way too. But until you do, load your factory rifles properly and try to understand the reasons for the differences or your magazine "wisdom" will present you with loading problems you don't yet have a clue how to deal with.
You read a lot of gun magazines, right?
When you start shooting $5,000 single shot BR rifles with hand made bullets in precisely turned case necks with such low "tension" you can finger seat long and let your rifling finish the job you should do it that way too. But until you do, load your factory rifles properly and try to understand the reasons for the differences or your magazine "wisdom" will present you with loading problems you don't yet have a clue how to deal with.
Looks like lots of ways to skin the cat but basically as long as the bullet fits and feeds from magazine, does not move with moderate force applied and are concentric, the amount of the bearing surface in the neck doesn't really matter. Am I understanding correctly?
You sure are a funnnneeee guy! I've been to a number of BR matches, and in fact $5000 wouldn't touch some of the rifles there. I believe the question is:"Minimum bullet seating depth? " Now Speaking about reading-it would do you some good to read the question, or maybe you just are a funneee guy.
Yea, your glasses must have fogged up, because I'm sure you didn't read my entire post! For if you had, you have read, "For repeaters, this practice is difficult, and unsafe at times, you're magazine will dictate the max OAL, and if you ever find yourself in a situation requiring to "make the line safe", chances are the bullet will stay in the barrel, and powder will be dumped from the case into your action. For those wanting to use "lighter" bullets, or more correctly "shorter" bullets, a discussion with your smith, and some dummy rounds will help him- help you in cutting your chamber".
What part of my post did you find not to be accurate? I believe you just don't have the wisdom to solve this loading problem, in fact you don't have a clue how to deal with it.
If in fact his chamber is cut in such a manner, as when shooting a short pill, he will have excessive jump, when loading magazine length, he only has a couple of options, what is your solution? That differs from mine oh wise one?
"That differs from mine oh wise one? "
My original post was and remains an effort to actually guide the new guy's thinking with helpful info outside the foolish "conventional wisdom" box. Your effort was and remains to build cred as a site accuracy expert but I feel no need to contest your esotoric arguments beyond what I've already said. The floor is yours to expound on "pills" as you will .....
My original post was and remains an effort to actually guide the new guy's thinking with helpful info outside the foolish "conventional wisdom" box. Your effort was and remains to build cred as a site accuracy expert but I feel no need to contest your esotoric arguments beyond what I've already said. The floor is yours to expound on "pills" as you will .....
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