How do you guys know how far a bullet is "seated off the lands"?
- Thread starter VaniB
- Start date
emn83
Its not uncommon for those case guages to need a little work to function smoothly.
They are after all just virgin brass from various manufacturers with all the defects virgin brass is known for.
Chamfer in and out.
Still sticky? roll some sandpaper up tight and insert into the case. Spin it by hand in the opposite direction of the roll. Try again.
I've found a loose fit on the bullet gives a more consistent reading than tight. Especially on factory barrels that may have thier own issues.
Its not uncommon for those case guages to need a little work to function smoothly.
They are after all just virgin brass from various manufacturers with all the defects virgin brass is known for.
Chamfer in and out.
Still sticky? roll some sandpaper up tight and insert into the case. Spin it by hand in the opposite direction of the roll. Try again.
I've found a loose fit on the bullet gives a more consistent reading than tight. Especially on factory barrels that may have thier own issues.
243Winxb: Just curious: how do you transfer the dimension you get with a flat base bullet seated up side down, to a meaningful dimension for the ogive ( the part of the bullet that will actually touch the lands), of the bullet?
As was mentioned, different bullets with different ogives, (could be anywhere from a 7 to a 12), will have different seating depths, and to throw an upside down bullet dimension into the equation, makes it even more confusing.
Why would you not take the dimension with the bullet you intend to use? Just askin!
As was mentioned, different bullets with different ogives, (could be anywhere from a 7 to a 12), will have different seating depths, and to throw an upside down bullet dimension into the equation, makes it even more confusing.
Why would you not take the dimension with the bullet you intend to use? Just askin!
MNFinn
Erik on the Range
jo191145 said:
Thanks for the ad vice, I'll try chamfering it and see if that eliminates that first step of resistance I feel. It was weird, because it felt like the bullet was rubbing, but a little further, I got a real firm stop where the bullet would not seat any further
emn83: That rubbing that you feel is the ogive of the bullet making its' first contact with the leade. Just push harder until you feel the bullet fully forward when it comes to a definate stop. That's the length you need to record & keep for future reference, at least until erosion causes the length to "grow".
Thanks for the ad vice, I'll try chamfering it and see if that eliminates that first step of resistance I feel. It was weird, because it felt like the bullet was rubbing, but a little further, I got a real firm stop where the bullet would not seat any further
[/quote]
I know exactly what you speak of. Been fooled by that myself. Usually caused by run out/ concentricity issues in the brass. Easiest fix is enlarging the ID of the case.
The bullet will self center if given the chance.
[/quote]
I know exactly what you speak of. Been fooled by that myself. Usually caused by run out/ concentricity issues in the brass. Easiest fix is enlarging the ID of the case.
The bullet will self center if given the chance.
DennisH
Life Time NRA member
This is my exact procedure using the Hornady OAL tool.
Wash your bullets, 6 or so in lacquer thinner so their clean, takes 5 seconds.
Make sure your chamber and Hornady measuring case is clean, clean the measuring case with steel wool.
On several occasions I would get different measurements and resistance. After doing the above before starting measurements, I will get 4 to 5 "exact" measurements out of 6 bullets. I've done this many times. .001 is not much and there could be something there affecting your measurement. Most of the time I have found the problem to be in the chamber, burnt powder, dust or something.
But one thing for sure, I do get consistant measurements. Putting the same force on the push rod is also very important, but I have found if everything is clean, you will not have any problem. You will also develop a feel when measuring, when pushing the bullet in, you will know when it hits the lands. You know you have dirt or something if you give a little extra push and the bullet goes in a little further! You will feel it.
One bullet I was impressed with is the Lapua 105 L. This is a very good bullet straight from Lapua. I will get the same measurement on all bullets almost 99.9% of the time! JLK's are pretty consistant.
I feel so confident with my above process, once I have three of the exact same measurements, and it could be the first 3, I use it and start loading. NOTE: Bullets are dirty from the factory!
Wash your bullets, 6 or so in lacquer thinner so their clean, takes 5 seconds.
Make sure your chamber and Hornady measuring case is clean, clean the measuring case with steel wool.
On several occasions I would get different measurements and resistance. After doing the above before starting measurements, I will get 4 to 5 "exact" measurements out of 6 bullets. I've done this many times. .001 is not much and there could be something there affecting your measurement. Most of the time I have found the problem to be in the chamber, burnt powder, dust or something.
But one thing for sure, I do get consistant measurements. Putting the same force on the push rod is also very important, but I have found if everything is clean, you will not have any problem. You will also develop a feel when measuring, when pushing the bullet in, you will know when it hits the lands. You know you have dirt or something if you give a little extra push and the bullet goes in a little further! You will feel it.
One bullet I was impressed with is the Lapua 105 L. This is a very good bullet straight from Lapua. I will get the same measurement on all bullets almost 99.9% of the time! JLK's are pretty consistant.
I feel so confident with my above process, once I have three of the exact same measurements, and it could be the first 3, I use it and start loading. NOTE: Bullets are dirty from the factory!
Mark the bullet on the ogive where it becomes full diameter. A case mouth sized with .001" neck tension, will mark the bullet, if spun in the case mouth. Then take the measurement from the dummy round. Set the case head to line on the ogive distance. Close enough for me. Maybe not bench rest? But the jam changes as the barrel get dirty, doesnt it?
fdshuster said:
Shoulder set back from the firing pin strike. Savage Axis 223
Its possible for the firing pin strike to set the shoulder back .006" on some bolt actions. It may depend on the type/fit of the extractor? Softness of the brass? This set back would effect the ogive distance from the lands/leade of a loaded round. Test- Chamber empty brass with a known shoulder set back of .001" Place a used primer in the case. Let the firing pin hit it. Measure. A 2nd strike may set the shoulder back even more?? What did you find?
Its possible for the firing pin strike to set the shoulder back .006" on some bolt actions. It may depend on the type/fit of the extractor? Softness of the brass? This set back would effect the ogive distance from the lands/leade of a loaded round. Test- Chamber empty brass with a known shoulder set back of .001" Place a used primer in the case. Let the firing pin hit it. Measure. A 2nd strike may set the shoulder back even more?? What did you find?
Doesn't any method (or tool) that doesn't involve closing the bolt (without firing pin,extractor or ejector)on a case really only give you the distance from the datum to the lands instead of the distance from the boltface to the lands? Isn't the boltface to lands dimension what we are looking to find/repeat when we use the Hornady comparator to measure an "on the lands" length? Just wonderin?
BoydAllen
Gold $$ Contributor
Neither the Sinclair tool, that uses a rod, adapter and collars, nor the Hornady tool that uses drilled and threaded cases require that you close the bolt to take a measurement. They do require a fired case, but is does not have to be modified, except to reseat or remove the primer, so that any crater is not above the case head. On the Sinclair tool the case is used directly, and on the Hornedy it is measured to compare its head to datum lenght so that a constant correction factor for that rifle can be determined.
I'm not familiar with the Sinclair tool but if it uses a case fired in your chamber and not re-sized it may give you an accurate indication of the boltface to lands measurement which is what you are checking/duplicating when you use the comparator/caliper to set your seating depth with regard to the lands. If a case which had the shoulder set back was used and pushed all the way into the chamber to take a measurement would not the head of the case be held to a point that distance off the boltface? Meaning that a measurement taken and duplicated using that distance would result in the bullet being as much short of reaching the lands as the case used to attain that measurement was off the boltface? I appreciate your patience in helping me to get my head around this.
No, it would not matter if the case shoulder was pushed back or not. The impoortant factor is the distance between the ogive of the bullet and the base of the case, which will be up against the boltface, if you have the bullet out enough to engage the lands.
The way I do it in this fashion is to keep seating the bullet a thou at a time till the bolt will just close with finger pressure only. Then make a new case and bullet of the same seating depth, blacken the bullet with a sharpie and insert it into the chambeer and close the bolt, if the lands are just barely touching the bullet and appear to be equal in their engagement of the lands, then I will usually run with this measurement. I used to use a stoney point tool, but I like doing it this way better!
The way I do it in this fashion is to keep seating the bullet a thou at a time till the bolt will just close with finger pressure only. Then make a new case and bullet of the same seating depth, blacken the bullet with a sharpie and insert it into the chambeer and close the bolt, if the lands are just barely touching the bullet and appear to be equal in their engagement of the lands, then I will usually run with this measurement. I used to use a stoney point tool, but I like doing it this way better!
i
Correct, The Hornady tool uses virgin brass (unless you make your own) as a gage and indexs off the shoulder when inserted into the chamber.
If that brass is .005" shorter than chamber dimensions your measurement will be off by that much.
Personally I never even bother making any corrections. I consider it an arbitrary starting point. Load development will tell me the correct seating depth. If the gage tells me I'm into the lands .020" and its really .015" I could care less. The gage may lie but as long as it lies consistently it works just fine for me.
jray57 said:
Correct, The Hornady tool uses virgin brass (unless you make your own) as a gage and indexs off the shoulder when inserted into the chamber.
If that brass is .005" shorter than chamber dimensions your measurement will be off by that much.
Personally I never even bother making any corrections. I consider it an arbitrary starting point. Load development will tell me the correct seating depth. If the gage tells me I'm into the lands .020" and its really .015" I could care less. The gage may lie but as long as it lies consistently it works just fine for me.
BoydAllen
Gold $$ Contributor
I agree with the point about it being an arbitrary starting point, but if someone asks me about what seating depth I am using, I like being able to give a number that is as accurate as I can manage, and since I have the tools at hand to measure cases from shoulder to head, and fired cases, this one time determination is not too much bother...for me.
I use an R-P tool as Woods explains well here:
http://www.reloadersnest.com/forum/topic.asp?TOPIC_ID=9027
This provides boltface to lands baseline with a given bullet(changes with other bullets).
243winxb, none of my cases change HS a bit on firing pin strike, or even on primer firing.
Though I can imagine this possibly happening with something like a 30-06(extremely shallow shoulder angles), I'd have to see it to believe it.
I headspace 1-1.5thou, and that's the only 'potential' of my dynamic OgvOAL shifting.
http://www.reloadersnest.com/forum/topic.asp?TOPIC_ID=9027
This provides boltface to lands baseline with a given bullet(changes with other bullets).
243winxb, none of my cases change HS a bit on firing pin strike, or even on primer firing.
Though I can imagine this possibly happening with something like a 30-06(extremely shallow shoulder angles), I'd have to see it to believe it.
I headspace 1-1.5thou, and that's the only 'potential' of my dynamic OgvOAL shifting.
Erik Cortina
Team Lapua Brux Borden Captain
With Hornady tool, you do not need to have a "good feel" when pushing the rod in. All you do is push it in as hard as you can, the bullet with get jammed in the lands. Pull tool out, push bullet out (it will get stuck in the lands. Cleaning rod works good), put bullet back in tool and measure. It will give you the most consistent readings.
That measurement is your "jam" point, if you load longer than that point you run a very high risk of leaving the bullet in the barrel when you eject a loaded round.
Use the "jam" point as the reference point. Work away from that point, depending on bullet, you can back off as much as .030" and still be in the lands before you start jumping the bullet.
Another note, all bullets have the same base to ogive measurement if you are using the correct tool to measure. If you use the Hornady, Sinclair, etc. where they measure high on the ogive then yes, almost all bullets will be different. But if you use a tool that measures where the ogive transitions into the bearing surface they all are the same, or extremely close given diameter differences.
Now, if you don't have the Hornady tool.
Make a dummy round using one of your good pieces of brass. Resize and load a bullet long. Remove firing pin assembly from bolt and chamber dummy round. Put some die wax on the bullet ogive and close the bolt. You should feel some resistance as you are closing the bolt, that's the bullet being seated deeper into the case. Snap bolt open and measure dummy round base to ogive and that's your "jam" point. Try another two or three to confirm and you are all set. Pull bullets from dummy rounds, resize, and load.
If your bullet stays stuck in the lands when you extract dummy round, you are seating bullet too far out. Seat deeper to where you feel some resistance but not too much when closing bolt. Make sure you take before and after measurements to make sure bullet was seater deeper into case.
Jam point is relative to your neck tension, that's why you can not use reject brass for this. You can repeat this process every 50-100 rounds to keep track of throat erosion.
That measurement is your "jam" point, if you load longer than that point you run a very high risk of leaving the bullet in the barrel when you eject a loaded round.
Use the "jam" point as the reference point. Work away from that point, depending on bullet, you can back off as much as .030" and still be in the lands before you start jumping the bullet.
Another note, all bullets have the same base to ogive measurement if you are using the correct tool to measure. If you use the Hornady, Sinclair, etc. where they measure high on the ogive then yes, almost all bullets will be different. But if you use a tool that measures where the ogive transitions into the bearing surface they all are the same, or extremely close given diameter differences.
Now, if you don't have the Hornady tool.
Make a dummy round using one of your good pieces of brass. Resize and load a bullet long. Remove firing pin assembly from bolt and chamber dummy round. Put some die wax on the bullet ogive and close the bolt. You should feel some resistance as you are closing the bolt, that's the bullet being seated deeper into the case. Snap bolt open and measure dummy round base to ogive and that's your "jam" point. Try another two or three to confirm and you are all set. Pull bullets from dummy rounds, resize, and load.
If your bullet stays stuck in the lands when you extract dummy round, you are seating bullet too far out. Seat deeper to where you feel some resistance but not too much when closing bolt. Make sure you take before and after measurements to make sure bullet was seater deeper into case.
Jam point is relative to your neck tension, that's why you can not use reject brass for this. You can repeat this process every 50-100 rounds to keep track of throat erosion.
BoydAllen
Gold $$ Contributor
Eric,
Although your shooting and reloading credentials are obvious, and extensive, I will disagree with some of what you have written on this subject. For years, I have loaded for my varmint rifles with bullets seated out .006 to .010 longer than the point that they stopped with very firm thumb pressure on the rod of a Sinclair tool, with no problems with pulled bullets, as long as my neck tension was in a "normal" range, usually about .002 to .003. Perhaps this situation is different ogive numbers, but I have a couple of different short range benchrest bullets that have double radius ogives where the part that contacts the rifilng is at least a nine, and I usually seat these out quite a bit with no problem.
The other thing that I would mention is that although an individual can use a word any way that he likes, I believe that for purposes of discussion that a more standardized use of terms should be used. I first learned of the use of the word jam as it relates to reloading close to thirty years ago. During that time, and since then I have read everything that I could lay my hands on on the subject of precision shooting and reloading for that purpose. From that experience, I believe that the term jam came into use in short range benchrest, to describe the maximum length to which a bullet could be seated, with the neck tension that was the same as would be used for the actual ammunition, without its being pushed back into the case as the round is chambered and the bolt closed. (I believe that in highpower competition, intentionally loading longer than this length is referred to as soft seating.) Over time I believe that the term has become corrupted, with shooters constantly referring to their seating bullets jammed, when what they really mean is that bullets are seated some length longer than the point at which they just touch the rifling. The internet has exacerbated this misuse.
There is one additional point. I do not think that I can get a bullet as far into the rifling with any amount of thumb pressure on a rod, as I can with the leverage provided by the closing cams when a bolt is closed during the chambering of a round, and since I have shot so many rounds seated longer than I could push the bullet with my thumb, I think that your approach to a maximum seating length, while yielding laudable results, may be a bit conservative. On the other hand, given that some readers may not have all of the necessary tools or experience to avoid problems that can occur procedures are not properly followed, it may be a very good approach.
If there is one thing that I have learned about reloading, it is that great shooters do not all subscribe to the same bullet seating practices, and if you look at their results, one has to conclude that there is more than one way to skin this particular cat. If one wishes to have early success in any shooting sport, learning to do exactly as the winners do is, I believe, the best approach. For this reason, I believe that your sharing how you determine where you seat your bullets to be of great value. Obviously it works very well.
As I said at the beginning, your results prove the effectiveness of what you do. I am mostly just quibbling about terminology.
Although your shooting and reloading credentials are obvious, and extensive, I will disagree with some of what you have written on this subject. For years, I have loaded for my varmint rifles with bullets seated out .006 to .010 longer than the point that they stopped with very firm thumb pressure on the rod of a Sinclair tool, with no problems with pulled bullets, as long as my neck tension was in a "normal" range, usually about .002 to .003. Perhaps this situation is different ogive numbers, but I have a couple of different short range benchrest bullets that have double radius ogives where the part that contacts the rifilng is at least a nine, and I usually seat these out quite a bit with no problem.
The other thing that I would mention is that although an individual can use a word any way that he likes, I believe that for purposes of discussion that a more standardized use of terms should be used. I first learned of the use of the word jam as it relates to reloading close to thirty years ago. During that time, and since then I have read everything that I could lay my hands on on the subject of precision shooting and reloading for that purpose. From that experience, I believe that the term jam came into use in short range benchrest, to describe the maximum length to which a bullet could be seated, with the neck tension that was the same as would be used for the actual ammunition, without its being pushed back into the case as the round is chambered and the bolt closed. (I believe that in highpower competition, intentionally loading longer than this length is referred to as soft seating.) Over time I believe that the term has become corrupted, with shooters constantly referring to their seating bullets jammed, when what they really mean is that bullets are seated some length longer than the point at which they just touch the rifling. The internet has exacerbated this misuse.
There is one additional point. I do not think that I can get a bullet as far into the rifling with any amount of thumb pressure on a rod, as I can with the leverage provided by the closing cams when a bolt is closed during the chambering of a round, and since I have shot so many rounds seated longer than I could push the bullet with my thumb, I think that your approach to a maximum seating length, while yielding laudable results, may be a bit conservative. On the other hand, given that some readers may not have all of the necessary tools or experience to avoid problems that can occur procedures are not properly followed, it may be a very good approach.
If there is one thing that I have learned about reloading, it is that great shooters do not all subscribe to the same bullet seating practices, and if you look at their results, one has to conclude that there is more than one way to skin this particular cat. If one wishes to have early success in any shooting sport, learning to do exactly as the winners do is, I believe, the best approach. For this reason, I believe that your sharing how you determine where you seat your bullets to be of great value. Obviously it works very well.
As I said at the beginning, your results prove the effectiveness of what you do. I am mostly just quibbling about terminology.
Erik Cortina
Team Lapua Brux Borden Captain
Boyd, I said "you run a very high risk of leaving the bullet in the barrel when you eject a loaded round". I too have seated bullets past that point with no problems, but the risk is there. Since I don't have time and are only giving basic seating depth advise, I am having to generalize some things and can not cover every possible scenario. I just know that if they follow the advice to stay away from "jam", then their chances of leaving a bullet in the lands is low.
As for the word "jam", I agree with you, that's why in my second method I advised to use a dummy round, to me that's the best way and the method I use. With the Hornady tool, it only gives you a reference point that I call "jam" due to lack of a better word. "Jam" is relative to neck tension with the dummy round, not so with the Hornady tool.
As for the word "jam", I agree with you, that's why in my second method I advised to use a dummy round, to me that's the best way and the method I use. With the Hornady tool, it only gives you a reference point that I call "jam" due to lack of a better word. "Jam" is relative to neck tension with the dummy round, not so with the Hornady tool.
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