I was hoping one of you guys could help me out. How do I better control my seating depth? I was checking some loads the other day and the base to ogive measurements varied by as much as .007". The reason I am asking is because I am trying to fine tune some loads and would like to tinker with the seating depth in .005" increments. I am just using a standard RCBS seating die at the moment.
Seating Depth
- Thread starter jpistolero02
- Start date
Re: Seating Depth
OAL varries, so what you need is the abiity to measure at the ogive. RCBS case micrometer or StoneyPoint (n.e. Hornady) tools give you this capability.
It helps a lot to have the bullet seating die push on the ogive instead of the nose (or flank) of the bullet. Typically, competition seaters do this, and regulars do not.
OAL varries, so what you need is the abiity to measure at the ogive. RCBS case micrometer or StoneyPoint (n.e. Hornady) tools give you this capability.
It helps a lot to have the bullet seating die push on the ogive instead of the nose (or flank) of the bullet. Typically, competition seaters do this, and regulars do not.
Re: Seating Depth
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jpistolero02</div><div class="ubbcode-body">I was hoping one of you guys could help me out. How do I better control my seating depth? I was checking some loads the other day and the base to ogive measurements varied by as much as .007". The reason I am asking is because I am trying to fine tune some loads and would like to tinker with the seating depth in .005" increments. I am just using a standard RCBS seating die at the moment. </div></div>
Get yourself an RCBS Competition seating die.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jpistolero02</div><div class="ubbcode-body">I was hoping one of you guys could help me out. How do I better control my seating depth? I was checking some loads the other day and the base to ogive measurements varied by as much as .007". The reason I am asking is because I am trying to fine tune some loads and would like to tinker with the seating depth in .005" increments. I am just using a standard RCBS seating die at the moment. </div></div>
Get yourself an RCBS Competition seating die.
Re: Seating Depth
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Shot In The Dark</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jpistolero02</div><div class="ubbcode-body">I was hoping one of you guys could help me out. How do I better control my seating depth? I was checking some loads the other day and the base to ogive measurements varied by as much as .007". The reason I am asking is because I am trying to fine tune some loads and would like to tinker with the seating depth in .005" increments. I am just using a standard RCBS seating die at the moment. </div></div>
Get yourself an RCBS Competition seating die. </div></div> You don't need one to be consistent....I'll tell you right now it sounds like your press is not setup correctly...
I don't care what dies you have, it should never vary more than ONE thou.
First question is, is your press cam'ing over? If you take the die out of the press completely, slowly raise the ram until it maxes out, watch closely and you'll see where the ram raises up to it's maximum height, and actually drops some before the handle hits and stops. The act of the ram cam'ing over is when it reaches it's maximum height and lowers slightly. Now every time you seat a bullet, size a piece of brass, etc. you should be cam'ing over. Now, start threading in your seating die, turn it 1/8th of a turn at a time and seat your round. Keep turning your die in 1/8th turn in until your round is the correct length. Now that you have it set, lock your ring in place. Now your rounds should never exceed more than one thou from each other (mind you this measurement is off the ogive).
If your varying more than 2-3 thou there is a couple things to check, one the joints on your press, sometimes the pins wear out and get grooves in them and as they rotate it hits high spots and sometimes the worn spots. I've had this issue and it took me forever to figure it out.
The only other thing would be you have the worst caste bullets known to man... So in short there is no reason you shouldn't be incredibly consistent. Also remember that although you maybe measuring a slight variance in base to tip measurements, (OAL) it's just the difference in the projectiles, but your base to ogive measurement will be right on.... Hope this helps, it's a common mistake to not have the press cam'ing over.....
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Shot In The Dark</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jpistolero02</div><div class="ubbcode-body">I was hoping one of you guys could help me out. How do I better control my seating depth? I was checking some loads the other day and the base to ogive measurements varied by as much as .007". The reason I am asking is because I am trying to fine tune some loads and would like to tinker with the seating depth in .005" increments. I am just using a standard RCBS seating die at the moment. </div></div>
Get yourself an RCBS Competition seating die. </div></div> You don't need one to be consistent....I'll tell you right now it sounds like your press is not setup correctly...
I don't care what dies you have, it should never vary more than ONE thou.
First question is, is your press cam'ing over? If you take the die out of the press completely, slowly raise the ram until it maxes out, watch closely and you'll see where the ram raises up to it's maximum height, and actually drops some before the handle hits and stops. The act of the ram cam'ing over is when it reaches it's maximum height and lowers slightly. Now every time you seat a bullet, size a piece of brass, etc. you should be cam'ing over. Now, start threading in your seating die, turn it 1/8th of a turn at a time and seat your round. Keep turning your die in 1/8th turn in until your round is the correct length. Now that you have it set, lock your ring in place. Now your rounds should never exceed more than one thou from each other (mind you this measurement is off the ogive).
If your varying more than 2-3 thou there is a couple things to check, one the joints on your press, sometimes the pins wear out and get grooves in them and as they rotate it hits high spots and sometimes the worn spots. I've had this issue and it took me forever to figure it out.
The only other thing would be you have the worst caste bullets known to man... So in short there is no reason you shouldn't be incredibly consistent. Also remember that although you maybe measuring a slight variance in base to tip measurements, (OAL) it's just the difference in the projectiles, but your base to ogive measurement will be right on.... Hope this helps, it's a common mistake to not have the press cam'ing over.....
Re: Seating Depth
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gunman_7</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Shot In The Dark</div><div class="ubbcode-body">
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gunman_7</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Shot In The Dark</div><div class="ubbcode-body">
jpistolero02 said:
Re: Seating Depth
The press is definitely caming over. I guess I will check all the pins to make sure everything is in good condition. Thanks for the heads up.
The press is definitely caming over. I guess I will check all the pins to make sure everything is in good condition. Thanks for the heads up.
Re: Seating Depth
OP. Not being a smart ass, but how are you measuring your ogive?
.007 is alot of variance.
OP. Not being a smart ass, but how are you measuring your ogive?
.007 is alot of variance.
Re: Seating Depth
It's a good question when you are dealing with a chachie like me. I am using a Sinclair comperator tool mounted to a Frankford Arsenal caliper.
It's a good question when you are dealing with a chachie like me. I am using a Sinclair comperator tool mounted to a Frankford Arsenal caliper.
Re: Seating Depth
While the sizing dies set-up directions leave alot on the table,
the bullet seating die instructions work.
Die set up is good?
Single stage press?
Calipers dont feel "crunchy"? Or skip?
The loads you checked were hot off the press? Hadnt been bouncing around in the toolbox of your truck?
While the sizing dies set-up directions leave alot on the table,
the bullet seating die instructions work.
Die set up is good?
Single stage press?
Calipers dont feel "crunchy"? Or skip?
The loads you checked were hot off the press? Hadnt been bouncing around in the toolbox of your truck?
Re: Seating Depth
It's a RCBS Rock Chucker press. I will verify everything is nice and tight on the press. Yes, these loads were hot off the press and everything seemed normal with the calipers. I will double check everything on my end to make sure I am not missing a step. I certainly appreciate the pointers.
It's a RCBS Rock Chucker press. I will verify everything is nice and tight on the press. Yes, these loads were hot off the press and everything seemed normal with the calipers. I will double check everything on my end to make sure I am not missing a step. I certainly appreciate the pointers.
Re: Seating Depth
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fuzzball</div><div class="ubbcode-body">The die brand and type is pretty much irrelivant but the press type is not. If you're using a turret - or the progressive variation - that range of difference isn't uncommon. </div></div>
I'm not so sure, yea turrets can have more play in the head unit, or play in the ram, but when everything makes contact to seat the bullet, regardless of loose tolerances it should be repeatable...
I seem to have close to the same setup as you, RCBS rock press with Redding dies, using stony point comparator with Frankfort caliper.... I literally just got done loading another 100rds of prairie dog ammo and I check the first on eand the last, neither varied by .0005.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fuzzball</div><div class="ubbcode-body">The die brand and type is pretty much irrelivant but the press type is not. If you're using a turret - or the progressive variation - that range of difference isn't uncommon. </div></div>
I'm not so sure, yea turrets can have more play in the head unit, or play in the ram, but when everything makes contact to seat the bullet, regardless of loose tolerances it should be repeatable...
I seem to have close to the same setup as you, RCBS rock press with Redding dies, using stony point comparator with Frankfort caliper.... I literally just got done loading another 100rds of prairie dog ammo and I check the first on eand the last, neither varied by .0005.
Re: Seating Depth
Also, your brass prep needs to be consistant. The neck can cause some variation from case to case. Virgin brass can give you some variation, if you don't prep them right. Also, if it's an overly compressed load, you'll get some variance.
Also, your brass prep needs to be consistant. The neck can cause some variation from case to case. Virgin brass can give you some variation, if you don't prep them right. Also, if it's an overly compressed load, you'll get some variance.
Re: Seating Depth
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: alf</div><div class="ubbcode-body">Some bullets vary that or more on just the base to ogive measurement.
Iffen you want to go there, you need to sort your bullets first. </div></div>
+1
You can sort by weight, ogive to base measurement, spin them on a Juenke Machine, or do it all. Pick your level of precision and go with it.
In your initial post you spoke of controlling the seating depth. I think the distance off of the lands will be a bigger trajectory influence than seating depth. If your seater is right, it will seat on the ogive, putting out consistent cartridge length, based on the ogive. This will give consistent distance off of the lands, subject to your head space tolerance.
Any variance in the ogive to bullet tip measurement will show up in varying cartridge overall length (measured case head to the tip). Any variance in the bullet base to ogive measurement will be buried in the case. I think you will find the pressure changes from reasonable variance in both to be small.
Good shooting
Ron
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: alf</div><div class="ubbcode-body">Some bullets vary that or more on just the base to ogive measurement.
Iffen you want to go there, you need to sort your bullets first. </div></div>
+1
You can sort by weight, ogive to base measurement, spin them on a Juenke Machine, or do it all. Pick your level of precision and go with it.
In your initial post you spoke of controlling the seating depth. I think the distance off of the lands will be a bigger trajectory influence than seating depth. If your seater is right, it will seat on the ogive, putting out consistent cartridge length, based on the ogive. This will give consistent distance off of the lands, subject to your head space tolerance.
Any variance in the ogive to bullet tip measurement will show up in varying cartridge overall length (measured case head to the tip). Any variance in the bullet base to ogive measurement will be buried in the case. I think you will find the pressure changes from reasonable variance in both to be small.
Good shooting
Ron
Re: Seating Depth
A variance from bullet base to ogive will show up internally on a reloaded round, or from ogive to bullet tip. Case head to ogive distance is very repeatable even with inconsitant weights in the projectiles being used.
Weight inconsitancies will not show up as ogive to case head inconsistancies.
A variance from bullet base to ogive will show up internally on a reloaded round, or from ogive to bullet tip. Case head to ogive distance is very repeatable even with inconsitant weights in the projectiles being used.
Weight inconsitancies will not show up as ogive to case head inconsistancies.
Re: Seating Depth
Which, OP, is probably your issue with your ogive measurement.
Your green box RCBS reloading die is more likely than not, not seating the bullet from the ogive. More likely it is contacting your bullet at an undetermined point well above the ogive and below the tip.
If you soot a few bullets while seating them, I bet you will find the mark where your seating shoe is contacting your bullet is very repeatable and consistent.
I dont know your shooting level, nor the abilities of your rifle.Nor am I slighting either. But Id bet dollars to donuts that there are very few folks on this forum that could actually benefit from handloads being rolled to such tolerances. I know I cant.
If a shooter is after sub MOA groups, and said shooter and his rifle are capable of such, that goal can be obtained with green box RCBS dies, and without ever hearing the word ogive. If said shooter masters 3/4 to 1/2 MOA and needs more accuracy, then by all means bump it up a level.
This is as much a reminder to myself as an offer of advice to anyone reading it. Match your reloading level to your shooting skills, and let them both grow at the same speed.
Which, OP, is probably your issue with your ogive measurement.
Your green box RCBS reloading die is more likely than not, not seating the bullet from the ogive. More likely it is contacting your bullet at an undetermined point well above the ogive and below the tip.
If you soot a few bullets while seating them, I bet you will find the mark where your seating shoe is contacting your bullet is very repeatable and consistent.
I dont know your shooting level, nor the abilities of your rifle.Nor am I slighting either. But Id bet dollars to donuts that there are very few folks on this forum that could actually benefit from handloads being rolled to such tolerances. I know I cant.
If a shooter is after sub MOA groups, and said shooter and his rifle are capable of such, that goal can be obtained with green box RCBS dies, and without ever hearing the word ogive. If said shooter masters 3/4 to 1/2 MOA and needs more accuracy, then by all means bump it up a level.
This is as much a reminder to myself as an offer of advice to anyone reading it. Match your reloading level to your shooting skills, and let them both grow at the same speed.
Re: Seating Depth
I ran into the same problem when I first started out, which is not that long ago. I was getting approx 5 thou difference in seating depth, measured tip to tip. Now I know that tip to tip is not exact. It was suggested to me that I put more pressure on the press when seating bullets. I found it easier to be consistent when I seated with more force. My consistency improved to 1-2 thousandths of an inch just buy putting more, and consistent force on the press.
Next thing I did was get a comparator and my rounds that were "off" 1-2 thou tip to tip, are acutally right on measured with the comparator. GK bullets with the Spitzer Point are not very consistent tip to tip.
I just started loading up some Scenars and have had no consistency problems thus far.
I ran into the same problem when I first started out, which is not that long ago. I was getting approx 5 thou difference in seating depth, measured tip to tip. Now I know that tip to tip is not exact. It was suggested to me that I put more pressure on the press when seating bullets. I found it easier to be consistent when I seated with more force. My consistency improved to 1-2 thousandths of an inch just buy putting more, and consistent force on the press.
Next thing I did was get a comparator and my rounds that were "off" 1-2 thou tip to tip, are acutally right on measured with the comparator. GK bullets with the Spitzer Point are not very consistent tip to tip.
I just started loading up some Scenars and have had no consistency problems thus far.
Re: Seating Depth
".. If you're using a turret - or the progressive variation - that range of difference isn't uncommon. <span style="font-weight: bold">...not so sure, yea turrets can have more play in the head unit, or play in the ram, .. </span>"
I spoke in general terms of course, there are certainly some variations. But any conventional turret/progressive press head - Lyman, Redding, Hornady, Dillon - that is attached by a center bolt HAS to have some slop in the attachment or the heads couldn't turn. (Lee's non-conventional turret/progressive heads also have some loosness but the way they're supported limits the effect on ammo.) And all presses have some degree of slop in the lever/ram linkages. How much pressure it takes to remove all of that press slop will determine how well we can eliminate variations when seating.
One of the reasons knowledgable reloaders like Lee's "Dead Length Seaters" is that, used correctly it totally removes the effect of press spring from any source, so OALs can be quite consistant. All seater stems press on the "ogive". Ogive is the entire curved section of the bullet profile, it's not limited to the point of rifling contact diameter. Die brands really don't matter a lot to consistancy of the OAL. (The Lee is good because of its design, not the brand)
All seaters have a firm, metal to metal, seating stem/cup at one end of the cartridge and a shell holder/ram at the other. Ignoring the effects of press spring, whatever components we put in the middle WILL be the same length between the ogive and head contact points IF we operate the press consistantly.
Mr. Frisky has learned a great truth; consistant, firm seating pressure reduces or even eliminats OAL variations due to press spring no matter what press we use.
".. If you're using a turret - or the progressive variation - that range of difference isn't uncommon. <span style="font-weight: bold">...not so sure, yea turrets can have more play in the head unit, or play in the ram, .. </span>"
I spoke in general terms of course, there are certainly some variations. But any conventional turret/progressive press head - Lyman, Redding, Hornady, Dillon - that is attached by a center bolt HAS to have some slop in the attachment or the heads couldn't turn. (Lee's non-conventional turret/progressive heads also have some loosness but the way they're supported limits the effect on ammo.) And all presses have some degree of slop in the lever/ram linkages. How much pressure it takes to remove all of that press slop will determine how well we can eliminate variations when seating.
One of the reasons knowledgable reloaders like Lee's "Dead Length Seaters" is that, used correctly it totally removes the effect of press spring from any source, so OALs can be quite consistant. All seater stems press on the "ogive". Ogive is the entire curved section of the bullet profile, it's not limited to the point of rifling contact diameter. Die brands really don't matter a lot to consistancy of the OAL. (The Lee is good because of its design, not the brand)
All seaters have a firm, metal to metal, seating stem/cup at one end of the cartridge and a shell holder/ram at the other. Ignoring the effects of press spring, whatever components we put in the middle WILL be the same length between the ogive and head contact points IF we operate the press consistantly.
Mr. Frisky has learned a great truth; consistant, firm seating pressure reduces or even eliminats OAL variations due to press spring no matter what press we use.
Re: Seating Depth
i had similar problems with compressed loads, crunching the bullet in, and measuring, then measuring 5 minutes later the bullets had pushed back out anywhere up to .005
(this was with lee neck collet tension, and redding comp seater)
i quit compressing loads.
i had similar problems with compressed loads, crunching the bullet in, and measuring, then measuring 5 minutes later the bullets had pushed back out anywhere up to .005
(this was with lee neck collet tension, and redding comp seater)
i quit compressing loads.
Re: Seating Depth
Maybe I was taught incorrectly the definition of ogive.
While the architecture term uses the entire curve, I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?
No?
Maybe I was taught incorrectly the definition of ogive.
While the architecture term uses the entire curve, I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?
No?
Re: Seating Depth
Very curious about this. Still wondering if I was taught wrong about the definition of bullet ogive?
Quite possibly I remember it wrong? Any input?
Id ask my reloading mentor but he went "down range" three years ago. (Sure wished I had paid better attention to everything he taught me, would have saved me alot of heartache over the last fourty years)
Your thoughts please.
Very curious about this. Still wondering if I was taught wrong about the definition of bullet ogive?
Quite possibly I remember it wrong? Any input?
Id ask my reloading mentor but he went "down range" three years ago. (Sure wished I had paid better attention to everything he taught me, would have saved me alot of heartache over the last fourty years)
Your thoughts please.
Re: Seating Depth
There are two different uses of the word Ogive (pronounced O-jive) as it pertains to projectiles.
#1 This ogive is the actual point behind the curve of the bullet nose where the main outside diameter of the bullet makes contact with the rifling of the barrel. This is the most common use of the word.
#2 This use of the word means the number or value given to the rounded nose of the bullet. In the late 1800s after the civil war MOST bullets of the time were just made on a true radius of half the diameter of the bullet. The more modern 30-06 Springfield round as designed by J. M. Browning around 1900 is credited with having the first production made "sharp nose" bullet. And later of having a boat tailed base. This ogive number is based on how many times the diameter of the bullet is the correct radius of the bullet nose.
So a 30 caliber projectile with a 7.0 ogive has a curved "nose" with the radius of basically half of the original measurement of 2.156" In the last couple of decades there has been much more work in the field of design of the modern projectile. While a lot of the data is repeated in history of the 20th century, some are only now being able to be mass produced. The many advances in modern machine tools has had no small amount of the praise in the newer bullets we can use at a very nominal price.
Therefore, the higher this ogive number the more pointy is the "nose" of the bullet. The VLD or Very Low Drag, type of projectiles as produced by Berger and now others, has a very sharp nose. But these bullets USUALLY are more difficult to get most accurately tuned to a specific chamber / rifle. As a general rule MOST boat tailed bullets are not quiet as accurate at short ranges, say between 50 and 250 yards. But they can hold their velocity VERY WELL for an extended range.
There are two different uses of the word Ogive (pronounced O-jive) as it pertains to projectiles.
#1 This ogive is the actual point behind the curve of the bullet nose where the main outside diameter of the bullet makes contact with the rifling of the barrel. This is the most common use of the word.
#2 This use of the word means the number or value given to the rounded nose of the bullet. In the late 1800s after the civil war MOST bullets of the time were just made on a true radius of half the diameter of the bullet. The more modern 30-06 Springfield round as designed by J. M. Browning around 1900 is credited with having the first production made "sharp nose" bullet. And later of having a boat tailed base. This ogive number is based on how many times the diameter of the bullet is the correct radius of the bullet nose.
So a 30 caliber projectile with a 7.0 ogive has a curved "nose" with the radius of basically half of the original measurement of 2.156" In the last couple of decades there has been much more work in the field of design of the modern projectile. While a lot of the data is repeated in history of the 20th century, some are only now being able to be mass produced. The many advances in modern machine tools has had no small amount of the praise in the newer bullets we can use at a very nominal price.
Therefore, the higher this ogive number the more pointy is the "nose" of the bullet. The VLD or Very Low Drag, type of projectiles as produced by Berger and now others, has a very sharp nose. But these bullets USUALLY are more difficult to get most accurately tuned to a specific chamber / rifle. As a general rule MOST boat tailed bullets are not quiet as accurate at short ranges, say between 50 and 250 yards. But they can hold their velocity VERY WELL for an extended range.
Re: Seating Depth
Victor,
Im thick headed... please be patient.
From #1 - Ogive is a specific relationship between a particular bullet and a particular rifle. For instance, n 175 smk in my LTR
would touch the rifling at one specific spot. But put the exact bullet in brand x rifle with an after market custom barrel of your choice, and we would more likely than not find a different ogive?
From #2 - Is a measurable point, on any bullet that is derived thru a mathematical equation to repeatedly find the same exact spot on like bullets.
For example and simplicity sake, we start with a .308 bullet,
we plug the apporopriate numbers into the formula, crunch them and come up with.....say .265. Now we can measure like bullets,find the diameter along the curve of the bullet of .265 and this is our ogive? Which is a repeatable process.
Did I grasp what your telling me?
Victor,
Im thick headed... please be patient.
From #1 - Ogive is a specific relationship between a particular bullet and a particular rifle. For instance, n 175 smk in my LTR
would touch the rifling at one specific spot. But put the exact bullet in brand x rifle with an after market custom barrel of your choice, and we would more likely than not find a different ogive?
From #2 - Is a measurable point, on any bullet that is derived thru a mathematical equation to repeatedly find the same exact spot on like bullets.
For example and simplicity sake, we start with a .308 bullet,
we plug the apporopriate numbers into the formula, crunch them and come up with.....say .265. Now we can measure like bullets,find the diameter along the curve of the bullet of .265 and this is our ogive? Which is a repeatable process.
Did I grasp what your telling me?
Re: Seating Depth
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: misguided child2</div><div class="ubbcode-body">Victor,
Im thick headed... please be patient.
From #1 - Ogive is a specific relationship between a particular bullet and a particular rifle. For instance, n 175 smk in my LTR
would touch the rifling at one specific spot. But put the exact bullet in brand x rifle with an after market custom barrel of your choice, and we would more likely than not find a different ogive? <span style="color: #FF0000">The ogive of the bullet isn't going to change. The relationship of the bullet and lands of the rifling is what will change.</span>
From #2 - Is a measurable point, on any bullet that is derived thru a mathematical equation to repeatedly find the same exact spot on like bullets. <span style="color: #FF0000">You are still confusing question #1 with #2 They are seperate terms for the same word.</span>For example and simplicity sake, we start with a .308 bullet,
we plug the apporopriate numbers into the formula, crunch them and come up with.....say .265. Now we can measure like bullets,find the diameter along the curve of the bullet of .265 and this is our ogive? Which is a repeatable process. <span style="color: #FF0000">You're still looking at question #1</span>
Did I grasp what your telling me? <span style="color: #FF0000">I think you missed it a little.</span>
</div></div> <span style="color: #FF0000"> </span>
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: misguided child2</div><div class="ubbcode-body">Victor,
Im thick headed... please be patient.
From #1 - Ogive is a specific relationship between a particular bullet and a particular rifle. For instance, n 175 smk in my LTR
would touch the rifling at one specific spot. But put the exact bullet in brand x rifle with an after market custom barrel of your choice, and we would more likely than not find a different ogive? <span style="color: #FF0000">The ogive of the bullet isn't going to change. The relationship of the bullet and lands of the rifling is what will change.</span>
From #2 - Is a measurable point, on any bullet that is derived thru a mathematical equation to repeatedly find the same exact spot on like bullets. <span style="color: #FF0000">You are still confusing question #1 with #2 They are seperate terms for the same word.</span>For example and simplicity sake, we start with a .308 bullet,
we plug the apporopriate numbers into the formula, crunch them and come up with.....say .265. Now we can measure like bullets,find the diameter along the curve of the bullet of .265 and this is our ogive? Which is a repeatable process. <span style="color: #FF0000">You're still looking at question #1</span>
Did I grasp what your telling me? <span style="color: #FF0000">I think you missed it a little.</span>
</div></div> <span style="color: #FF0000"> </span>
Re: Seating Depth
Let's see if this paste works... This is maybe a better explanation of #2. Copied from "Answers.com"
Applied physical science and engineering
A secant ogive of sharpness E = 120 / 100 = 1.2In ballistics or aerodynamics, an ogive is a pointed, curved surface mainly used to form the approximately streamlined nose of a bullet or other projectile.
The traditional or secant ogive is a surface of revolution of the same curve that forms a Gothic arch; that is, a circular arc, of greater radius than the diameter of the cylindrical section ("shank"), is drawn from the edge of the shank until it intercepts the axis.
If this arc is drawn so that it meets the shank at zero angle (that is, the distance of the centre of the arc from the axis, plus the radius of the shank, equals the radius of the arc), then it is called a tangential or spitzer ogive. This is a very common ogive for high velocity (supersonic) rifle bullets.
Ogive on a 9mm cartridgeThe sharpness of this ogive is expressed by the ratio of its radius to the diameter of the cylinder; a value of one half being a hemispherical dome, and larger values being progressively more pointed. Values of 4 to 10 are commonly used in rifles, with 6 being the most common.
Another common ogive for bullets is the elliptical ogive. This is a curve very similar to the spitzer ogive, except that the circular arc is replaced by an ellipse defined in such a way that it meets the axis at exactly 90°. This gives a somewhat rounded nose regardless of the sharpness ratio. An elliptical ogive is normally described in terms of the ratio of the length of the ogive to the diameter of the shank. A ratio of one half would be, once again, a hemisphere. Values close to 1 are common in practice. Elliptical ogives are mainly used in pistol bullets.
Missiles and aircraft generally have much more complex ogives, such as the von Kármán ogive.
Let's see if this paste works... This is maybe a better explanation of #2. Copied from "Answers.com"
Applied physical science and engineering
A secant ogive of sharpness E = 120 / 100 = 1.2In ballistics or aerodynamics, an ogive is a pointed, curved surface mainly used to form the approximately streamlined nose of a bullet or other projectile.
The traditional or secant ogive is a surface of revolution of the same curve that forms a Gothic arch; that is, a circular arc, of greater radius than the diameter of the cylindrical section ("shank"), is drawn from the edge of the shank until it intercepts the axis.
If this arc is drawn so that it meets the shank at zero angle (that is, the distance of the centre of the arc from the axis, plus the radius of the shank, equals the radius of the arc), then it is called a tangential or spitzer ogive. This is a very common ogive for high velocity (supersonic) rifle bullets.
Ogive on a 9mm cartridgeThe sharpness of this ogive is expressed by the ratio of its radius to the diameter of the cylinder; a value of one half being a hemispherical dome, and larger values being progressively more pointed. Values of 4 to 10 are commonly used in rifles, with 6 being the most common.
Another common ogive for bullets is the elliptical ogive. This is a curve very similar to the spitzer ogive, except that the circular arc is replaced by an ellipse defined in such a way that it meets the axis at exactly 90°. This gives a somewhat rounded nose regardless of the sharpness ratio. An elliptical ogive is normally described in terms of the ratio of the length of the ogive to the diameter of the shank. A ratio of one half would be, once again, a hemisphere. Values close to 1 are common in practice. Elliptical ogives are mainly used in pistol bullets.
Missiles and aircraft generally have much more complex ogives, such as the von Kármán ogive.
Re: Seating Depth
OK. # 2 is beyond my current state of thinking.
But of #1...if it's the actual point where the bullet touches the rifling, would that point not change if I changed the rifling? Or kept the same rifling, but changed the geometry of the projectile?
Tighter barrel, the point of contact would move forward. Looser barrel the point of contact would move closer to the bearing surface of the bullet.
Thanks for your patience.
MGC
OK. # 2 is beyond my current state of thinking.
But of #1...if it's the actual point where the bullet touches the rifling, would that point not change if I changed the rifling? Or kept the same rifling, but changed the geometry of the projectile?
Tighter barrel, the point of contact would move forward. Looser barrel the point of contact would move closer to the bearing surface of the bullet.
Thanks for your patience.
MGC
Re: Seating Depth
That point on the bullet is NOT going to change. It's the point where the straight part of the bullet starts the curve. There is a pretty strict agreement among barrel and bullet makers that the inside bore of the barrel is a given 0.XXX inches. Also in respect the bottoms of the grooves that size must be 0.YYY inches. This might vary a few tenths or maybe even a thousandth or so. Changing barrels, chambers, reamers whatever might change where the bullet actually contacts the lands of the rifling, in the sence of how far it has to stick out to make contact. But the particular point of the bullet that makes contact will not change. Or it will be so small as to not be measured. After the rifle has been fired 100 rounds the throat will erode to the point that the contact point of the lands has moved .001 or .002"
That point on the bullet is NOT going to change. It's the point where the straight part of the bullet starts the curve. There is a pretty strict agreement among barrel and bullet makers that the inside bore of the barrel is a given 0.XXX inches. Also in respect the bottoms of the grooves that size must be 0.YYY inches. This might vary a few tenths or maybe even a thousandth or so. Changing barrels, chambers, reamers whatever might change where the bullet actually contacts the lands of the rifling, in the sence of how far it has to stick out to make contact. But the particular point of the bullet that makes contact will not change. Or it will be so small as to not be measured. After the rifle has been fired 100 rounds the throat will erode to the point that the contact point of the lands has moved .001 or .002"
Re: Seating Depth
" I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?
No?"
As I asked from up above. Then I inquired if I was incorrect.
I believe we are saying the same thing. No?
" I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?
No?"
As I asked from up above. Then I inquired if I was incorrect.
I believe we are saying the same thing. No?
Re: Seating Depth
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: misguided child2</div><div class="ubbcode-body">" I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?
</div></div>
That is one correct meaning of the word. Look at my first reply and #1
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: misguided child2</div><div class="ubbcode-body">" I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?
</div></div>
That is one correct meaning of the word. Look at my first reply and #1
Re: Seating Depth
Which was my question based on.....
"Ogive is the entire curved section of the bullet profile, it's not limited to the point of rifling contact diameter." As posted above.
Which, to my very limited knowledge of the english language loosely translates into the architecture definition of the word ogive.
Which was my question based on.....
"Ogive is the entire curved section of the bullet profile, it's not limited to the point of rifling contact diameter." As posted above.
Which, to my very limited knowledge of the english language loosely translates into the architecture definition of the word ogive.
Re: Seating Depth
Ahhhhh......
So,
"While the architecture term uses the entire curve, I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?"
was GTG all along.
Ahhhhh......
So,
"While the architecture term uses the entire curve, I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?"
was GTG all along.
Re: Seating Depth
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gunman_7</div><div class="ubbcode-body">LOL @ this conversation... talk about beating a dead horse to death, yet somehow continually very informational... </div></div>
Thank you for that. I hate to think that no one else was paying attention.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gunman_7</div><div class="ubbcode-body">LOL @ this conversation... talk about beating a dead horse to death, yet somehow continually very informational... </div></div>
Thank you for that. I hate to think that no one else was paying attention.
Re: Seating Depth
Misguided - "I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?"
Correct. But, it may be more easily expressed as "The entire curve between body diameter and meplat." Like other things in reloading, it's so easy to get tangled up in technical vines and forests of words that the original simple question gets lost!
Obviously, the only part of the ogive that affects handloaders is the rifling contact point on the ogive that matches bore diameter, and then only as a reference for seating. That "contact point" seems to throw something of a fog on "ogive" as it gets defined to many of us. That need not be; it isn't complex to understand nor hard to expain.
Misguided - "I was taught that bullet ogive is the exact measurable point where the bullet transforms in shape from the load bearing surface to the point of the bullet?"
Correct. But, it may be more easily expressed as "The entire curve between body diameter and meplat." Like other things in reloading, it's so easy to get tangled up in technical vines and forests of words that the original simple question gets lost!
Obviously, the only part of the ogive that affects handloaders is the rifling contact point on the ogive that matches bore diameter, and then only as a reference for seating. That "contact point" seems to throw something of a fog on "ogive" as it gets defined to many of us. That need not be; it isn't complex to understand nor hard to expain.
Re: Seating Depth
Thank you fuzzball. I personally work better with laymans terms.
And I personally follow the KISS method on my own bench.
Thank you fuzzball. I personally work better with laymans terms.
And I personally follow the KISS method on my own bench.
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