The scenario is as follows:

a) I'm using 55g Sierra Blitz Kings.

b) I measured the overall cartridge length (projectile touching the lands) by using a case with two slots cut into the neck parallel to the axis of the case. I then carefuly extracted the cartridge and measured base to tip. I then came up with an average (10 readings) of 2.341"

c) I'm getting good group results with an overall length of 2.321" (.020" off the lands).

d) This weekend I bought a Stoney Point Bullet Comparitor and started to re-measure the ovarall length, projectile touching the lands.

Problem 1. I managed to get 5 readings before the projectile stuck in the lands. I've tried using the seating die to seat the projectile over long but still no success. The average of the 6 readings I was able to get with the comparitor was 1.955" making an overall length 0.020" off the lands of 1.935".

e) I have some loaded cartridges with the overall length 2.321" base to tip, so decided to measure a few using the Bullet Comparitor to see how they would compare. 9 readings gave an average of 1.916" which means, to my calculations, the projectile is seated 0.039" off the lands.

Problem 2. I'M CONFUSED AND NEED HELP.

Regards,

I take it you don`t have/aren`t useing the Stoney Point OAL gage, only the "comparator"?

I`d suggest marking a bullet ogive with "magic marker" or "smokeing" and starting with a COL long enough to touch the lands when chambering, (useing a empty case) seat in 1/8 turn increments until the marks from the lands disapear. Take a measurment with the Stoney Point and record that as "just off" the leade. Now you can reduce the COL as you wish, disreguarding the base to tip lenght. The bullet tips vary and you will get a much more consistant measurment off the ogive. I

G'day Steyrl.
I'm sure I know the answer, but I'm not sure of the question.

Um, does the comparator only measure from the ogive of the bullet, whereas you started measuring the total OAL at first.?
I'm confused by anything I can't see and most that I can see.

Had the same problem. Still have it. I have found that BK seem to vary often on the ogive.
In fact shot today right after reloading and found some to chamber a little tighter or easier than others.
Kept track and the easier ones always shot low, the tighter ones slightly higher. Wish I had a cure.?
My rifle a cooper m21 223 shoots great with them, but I am
realy starting to notice this phenomina.

Hi JAL,

I'm confused because the COL measurement (measuring base of cartridge to tip of projectile) with the projectile seated .020" off the lands is 2.321". Measuring these same cartridges with the comparitor and comparing this with the COL with the the projectile touching the lands once again using the comparitor suggests the projectile is seated .039" off the lands. Why the difference??

quote:

Originally posted by JAL:
G'day Steyrl.
I'm sure I know the answer, but I'm not sure of the question.

Um, does the comparator only measure from the ogive of the bullet, whereas you started measuring the total OAL at first.?
I'm confused by anything I can't see and most that I can see.

Thanks for the advice Joe!

No, I'm not using the OAL guage only the comparitor.
Have you ever used the case with the cuts parallel to the long axis way of measuring OAL?

quote:

Originally posted by Ol` Joe:
I take it you don`t have/aren`t useing the Stoney Point OAL gage, only the "comparator"?

I`d suggest marking a bullet ogive with "magic marker" or "smokeing" and starting with a COL long enough to touch the lands when chambering, (useing a empty case) seat in 1/8 turn increments until the marks from the lands disapear. Take a measurment with the Stoney Point and record that as "just off" the leade. Now you can reduce the COL as you wish, disreguarding the base to tip lenght. The bullet tips vary and you will get a much more consistant measurment off the ogive. I

G'day Slay,
I'm starting to get the impression the more technical you get the more things seem to go unexpectedly. But if I kept it simple then I'd probably loose interest plus the amount of information I have already gained from this forum is amazing. There are some really knowledgable shooters out there!

Best regards,

quote:

Originally posted by Slay:
Had the same problem. Still have it. I have found that BK seem to vary often on the ogive.
In fact shot today right after reloading and found some to chamber a little tighter or easier than others.
Kept track and the easier ones always shot low, the tighter ones slightly higher. Wish I had a cure.?
My rifle a cooper m21 223 shoots great with them, but I am
realy starting to notice this phenomina.

[QUOTE]Originally posted by steyrl:
Hi JAL,

I'm confused because the COL measurement (measuring base of cartridge to tip of projectile) with the projectile seated .020" off the lands is 2.321". Measuring these same cartridges with the comparitor and comparing this with the COL with the the projectile touching the lands once again using the comparitor suggests the projectile is seated .039" off the lands. Why the difference??



I never was any good with puzzles, but, I'm wondering if when the comparitor measures the cart. on the ogive, it's a different part of the ogive that hits the lands?

Anyway, I'd only use the comparator to set/reset the distance you already have sucess with or to measure and record any new seating depth you wish to try. Knowing the actual distance off the lands doesn't matter a damn, as long as you can set the most accurate position. And even that is probably into Benchrest comp. domain.

Hey Mate,
You could be onto something. Let's see if we get any other responses. Today I ordered a Stoney Point OAl gauge so I'll see what happens when I get it.

quote:

Originally posted by JAL:
[QUOTE]Originally posted by steyrl:
Hi JAL,

I'm confused because the COL measurement (measuring base of cartridge to tip of projectile) with the projectile seated .020" off the lands is 2.321". Measuring these same cartridges with the comparitor and comparing this with the COL with the the projectile touching the lands once again using the comparitor suggests the projectile is seated .039" off the lands. Why the difference??



I never was any good with puzzles, but, I'm wondering if when the comparitor measures the cart. on the ogive, it's a different part of the ogive that hits the lands?

Anyway, I'd only use the comparator to set/reset the distance you already have sucess with or to measure and record any new seating depth you wish to try. Knowing the actual distance off the lands doesn't matter a damn, as long as you can set the most accurate position. And even that is probably into Benchrest comp. domain.

quote:

Originally posted by steyrl:
...I'm starting to get the impression the more technical you get the more things seem to go unexpectedly. ...

That is a very astute observation. This might help you, it is a bit lengthy and requires no special Tool.
---

Seating Depth can be found in a number of ways. Some folks like to use a special tool made by Stoney Point and others, but I’ve used the old Cleaning Rod Method for years and it still works great for me. You will want to repeat this entire Process each time you open a new box of Bullets, even if it is the exact same type and weight.

You will need:
1. A long Cleaning Rod or Dowel Rod. If using a Dowel Rod, use it where I mention using the Cleaning Rod below.
2. A Flat Tipped Jag. (Not needed if using a Dowel Rod.)
3. A 0.001" capable set of Calipers.
4. A roll of Tape, masking tape works fine.
5. A single Set-Up Bullet.
6. An item to hold the Set-Up Bullet against the Lands.
7. The rifle.
8. A small piece of paper.

A. Screw the Flat Tipped Jag into the Cleaning Rod. I have some made of Brass that had a sharp point on the end which I filed off just for this. Or use the Dowel Rod.
B. With the Rifle unloaded and the Bolt closed, slide the Cleaning Rod in the muzzle until the Jag touches the Bolt Face.
C. Place a single wrap of Tape around the Cleaning Rod so the front edge of the Tape is against the Muzzle.
D. Remove the Cleaning Rod and remove the Bolt from the rifle if it is a Bolt Action. It is a Lever or Semi-auto just open the Bolt.
E. Drop the Set-Up Bullet point first into the Chamber.
F. Reinsert the Cleaning Rod in the Muzzle and slide it down to the Set-Up Bullet while holding something against the Bullet Base(item 5). Depending on the diameter of the Bullet, you might be able to use a wooden pencil, an old cartridge case with the mouth slightly crimped closed or a loaded cartridge to hold the Set-Up Bullet in position.
G. Take your 0.001" capable set of Calipers and measure the distance from front edge of the Tape to the Muzzle.
H. Record the measurement on a small piece of paper and Tape it to the Set-Up Bullet.

That measurement gives you the Overall Cartridge Length(OCL) for the Set-Up Bullet to just Kiss-the-Lands. Keep the Set-Up Bullet separate from the others because you will use it to properly adjust the Seating Die later on. I just put it in the Die Box to keep it separated.

Converting Overall Cartridge Length(OCL) to Overall Die Length(ODL)

It is important to understand that all Bullets in a box are not the same exact Length. This is due to minute variations in the amount of material being formed into the Bullet. Fortunately the distance from the Point on the Ogive that makes contact with the Lands to the Bullet Base is normally very accurate.

Most Seating Die Stems are cupped deep enough so the Bullet Tip does not make contact with the Seating Stem. Some of the Super Sleek Plastic Tip Bullets do touch the Seating Stem and this may or may not be a problem. Remove the Seating Stem and insert the Bullet into the Cup. If it Wobbles around, that means the Tip is making contact and not the Ogive.

You can either modify the Seating Stem so the Bullet Tip is not touching, or contact your Die Manufacturer to see if they have a specific Seating Stem designed for that new sleek Bullet. If you do choose to modify the Seating Stem, go on and order a Spare or two in case the one you have gets damaged during the modification.

The main thing is to have all the Bullets Seated so the Point on the Ogive that makes contact with the Rifle Lands is the same distance from the Case Head from cartridge to cartridge. You can measure this with a Stoney Point Tool(if you have one), a Sinclair Bullet Comparator, or a Socket out of your Tool Box. Just use the Largest Socket you have which will not slip past the Ogive, place it on the Bullet and measure to the Case Head. If the Ogive-to-Case Head length varies a good bit, then you need to Seat each Bullet individually, or fix the Seating Stem.

You can make a Dummy Cartridge with no Primer and no Powder using the Set-Up Bullet if you want to, but it is really not necessary unless you intend to Crimp the Bullets. When Crimping the Bullets, it will save a lot of time to have a Dummy from Step #8 below. For consistency, all Cases should be Trimmed to the proper length, deburred and chamfered.

1. Take a Primed case that has the Powder in it and insert it into the Press Shell Holder and raise the Ram.
2. With the Seating Die out of the Press, screw the Seating Stem all the way up.
3. Screw the Seating Die into the Press until you feel it make contact with the Case and back it up ½ turn.
4. Screw the Seating Die Lock Ring down to touch the Press. If you do not intend to Crimp the Case, you can snug-up the Lock Ring Set Screw. Make sure you can still unscrew and reseat the Sizing Die to the same depth. It is critical for the Lock Ring not to move on the Seating Die so you can always screw the Seating Die into the same position. If you do desire to Crimp the Bullet, do not tighten the Set Screw and make sure you make a Dummy Cartridge. Crimping will be done in a separate Step.
5. Lower the Ram, place the Set-Up Bullet atop the Case and raise the Ram.
6. Screw the Seating Stem in until it touches the Set-Up Bullet, lower the ram slightly, screw the Seating Stem in a bit more and raise the ram.
7. Remove the Cartridge and measure the OCL. Repeat #6 and #7 until the OCL is the exact same as what you measured with the Cleaning Rod.
8. Place the Cartridge back in the Shell Holder and raise the ram.
9. Snug the Seating Stem Lock Nut into position.

Here is where all the above allows us to convert from OCL to ODL.

10. Lower the Cartridge and unscrew the Seating Die from the Press.
11. Take your 0.001" capable Calipers and measure from the top of the Seating Stem to the very bottom of the Seating Die.

This is the Overall Die Length(ODL) for the Set-Up Bullet and you will want to record this length on the actual Bullet Box.

For an Example, lets say the OCL was 3.280" and when we complete the above process, the ODL is 4.300". We now know we can take any Bullet out of that box and Seat it to just Kiss-the-Lands with the ODL set at 4.300". Or of we want to Seat Bullets 0.025" Off-the-Lands, we simply adjust the Seating Stem to 4.275", screw the Seating Die into the Press and we are ready to begin Seating Bullets.

If the Seating Die Lock Ring moves, then all measurements will be off. So it is important to have the Set Screw SNUG, but not so tight that you round out the Hex.

On Cartridges that I Crimp, I always Crimp into a Cannelure. I leave the Lock Ring Loose on those Dies and perform Bullet Seating and Crimping as two separate steps. Here a Dummy Cartridge can save you a good bit of Set-Up time.

I know that looks like a lot of stuff to do, and I guess it is. The Set-Up Bullet needs to be done each time you open a new box of bullets because of slight variances during manufacture. And occasionally the Manufacturers have to replace the Forming Dies which can change the Ogive shape and position.

It you have a rifle that uses a high Pressure cartridge and you shoot it a good bit, the Throat will recede a bit as you shoot it. So, this also helps keep up with that process.

As usual, use what you want and trash the rest.

quote:

c) I'm getting good group results with an overall length of 2.321" (.020" off the lands).

If that is true, why are you even fooling with it?

If it works, don't fix it...

[Hot Core,
Thanks for taking the time to reply I really appreciate the information. In fact I've printed your reply and it's pinned to the notice board in the gun room.

Best regards,

Steyrl
QUOTE]Originally posted by Hot Core:

quote:

Originally posted by steyrl:
...I'm starting to get the impression the more technical you get the more things seem to go unexpectedly. ...

That is a very astute observation. This might help you, it is a bit lengthy and requires no special Tool.
---

Seating Depth can be found in a number of ways. Some folks like to use a special tool made by Stoney Point and others, but I’ve used the old Cleaning Rod Method for years and it still works great for me. You will want to repeat this entire Process each time you open a new box of Bullets, even if it is the exact same type and weight.

You will need:
1. A long Cleaning Rod or Dowel Rod. If using a Dowel Rod, use it where I mention using the Cleaning Rod below.
2. A Flat Tipped Jag. (Not needed if using a Dowel Rod.)
3. A 0.001" capable set of Calipers.
4. A roll of Tape, masking tape works fine.
5. A single Set-Up Bullet.
6. An item to hold the Set-Up Bullet against the Lands.
7. The rifle.
8. A small piece of paper.

A. Screw the Flat Tipped Jag into the Cleaning Rod. I have some made of Brass that had a sharp point on the end which I filed off just for this. Or use the Dowel Rod.
B. With the Rifle unloaded and the Bolt closed, slide the Cleaning Rod in the muzzle until the Jag touches the Bolt Face.
C. Place a single wrap of Tape around the Cleaning Rod so the front edge of the Tape is against the Muzzle.
D. Remove the Cleaning Rod and remove the Bolt from the rifle if it is a Bolt Action. It is a Lever or Semi-auto just open the Bolt.
E. Drop the Set-Up Bullet point first into the Chamber.
F. Reinsert the Cleaning Rod in the Muzzle and slide it down to the Set-Up Bullet while holding something against the Bullet Base(item 5). Depending on the diameter of the Bullet, you might be able to use a wooden pencil, an old cartridge case with the mouth slightly crimped closed or a loaded cartridge to hold the Set-Up Bullet in position.
G. Take your 0.001" capable set of Calipers and measure the distance from front edge of the Tape to the Muzzle.
H. Record the measurement on a small piece of paper and Tape it to the Set-Up Bullet.

That measurement gives you the Overall Cartridge Length(OCL) for the Set-Up Bullet to just Kiss-the-Lands. Keep the Set-Up Bullet separate from the others because you will use it to properly adjust the Seating Die later on. I just put it in the Die Box to keep it separated.

Converting Overall Cartridge Length(OCL) to Overall Die Length(ODL)

It is important to understand that all Bullets in a box are not the same exact Length. This is due to minute variations in the amount of material being formed into the Bullet. Fortunately the distance from the Point on the Ogive that makes contact with the Lands to the Bullet Base is normally very accurate.

Most Seating Die Stems are cupped deep enough so the Bullet Tip does not make contact with the Seating Stem. Some of the Super Sleek Plastic Tip Bullets do touch the Seating Stem and this may or may not be a problem. Remove the Seating Stem and insert the Bullet into the Cup. If it Wobbles around, that means the Tip is making contact and not the Ogive.

You can either modify the Seating Stem so the Bullet Tip is not touching, or contact your Die Manufacturer to see if they have a specific Seating Stem designed for that new sleek Bullet. If you do choose to modify the Seating Stem, go on and order a Spare or two in case the one you have gets damaged during the modification.

The main thing is to have all the Bullets Seated so the Point on the Ogive that makes contact with the Rifle Lands is the same distance from the Case Head from cartridge to cartridge. You can measure this with a Stoney Point Tool(if you have one), a Sinclair Bullet Comparator, or a Socket out of your Tool Box. Just use the Largest Socket you have which will not slip past the Ogive, place it on the Bullet and measure to the Case Head. If the Ogive-to-Case Head length varies a good bit, then you need to Seat each Bullet individually, or fix the Seating Stem.

You can make a Dummy Cartridge with no Primer and no Powder using the Set-Up Bullet if you want to, but it is really not necessary unless you intend to Crimp the Bullets. When Crimping the Bullets, it will save a lot of time to have a Dummy from Step #8 below. For consistency, all Cases should be Trimmed to the proper length, deburred and chamfered.

1. Take a Primed case that has the Powder in it and insert it into the Press Shell Holder and raise the Ram.
2. With the Seating Die out of the Press, screw the Seating Stem all the way up.
3. Screw the Seating Die into the Press until you feel it make contact with the Case and back it up ½ turn.
4. Screw the Seating Die Lock Ring down to touch the Press. If you do not intend to Crimp the Case, you can snug-up the Lock Ring Set Screw. Make sure you can still unscrew and reseat the Sizing Die to the same depth. It is critical for the Lock Ring not to move on the Seating Die so you can always screw the Seating Die into the same position. If you do desire to Crimp the Bullet, do not tighten the Set Screw and make sure you make a Dummy Cartridge. Crimping will be done in a separate Step.
5. Lower the Ram, place the Set-Up Bullet atop the Case and raise the Ram.
6. Screw the Seating Stem in until it touches the Set-Up Bullet, lower the ram slightly, screw the Seating Stem in a bit more and raise the ram.
7. Remove the Cartridge and measure the OCL. Repeat #6 and #7 until the OCL is the exact same as what you measured with the Cleaning Rod.
8. Place the Cartridge back in the Shell Holder and raise the ram.
9. Snug the Seating Stem Lock Nut into position.

Here is where all the above allows us to convert from OCL to ODL.

10. Lower the Cartridge and unscrew the Seating Die from the Press.
11. Take your 0.001" capable Calipers and measure from the top of the Seating Stem to the very bottom of the Seating Die.

This is the Overall Die Length(ODL) for the Set-Up Bullet and you will want to record this length on the actual Bullet Box.

For an Example, lets say the OCL was 3.280" and when we complete the above process, the ODL is 4.300". We now know we can take any Bullet out of that box and Seat it to just Kiss-the-Lands with the ODL set at 4.300". Or of we want to Seat Bullets 0.025" Off-the-Lands, we simply adjust the Seating Stem to 4.275", screw the Seating Die into the Press and we are ready to begin Seating Bullets.

If the Seating Die Lock Ring moves, then all measurements will be off. So it is important to have the Set Screw SNUG, but not so tight that you round out the Hex.

On Cartridges that I Crimp, I always Crimp into a Cannelure. I leave the Lock Ring Loose on those Dies and perform Bullet Seating and Crimping as two separate steps. Here a Dummy Cartridge can save you a good bit of Set-Up time.

I know that looks like a lot of stuff to do, and I guess it is. The Set-Up Bullet needs to be done each time you open a new box of bullets because of slight variances during manufacture. And occasionally the Manufacturers have to replace the Forming Dies which can change the Ogive shape and position.

It you have a rifle that uses a high Pressure cartridge and you shoot it a good bit, the Throat will recede a bit as you shoot it. So, this also helps keep up with that process.

As usual, use what you want and trash the rest.[/QUOTE]

quote:

Originally posted by steyrl:
Hot Core,
Thanks for taking the time to reply I really appreciate the information. In fact I've printed your reply and it's pinned to the notice board in the gun room.

Hey Steyrl, You are welcome. Once you get used to doing it, it isn't all that difficult and helps maintain accuracy.

Best of luck to you.

You're absolutely right mate and normally I would leave it alone. BUT, there's that little question of whether I can get better than "good". I appreciate "good" can be a relative term, however, there's "good", "better" and "best".

Thanks for the comment, I do value all the comments I read.

Thanks Mate!

The question is can I get better than "good"

quote:

Originally posted by ricciardelli:

quote:

c) I'm getting good group results with an overall length of 2.321" (.020" off the lands).

If that is true, why are you even fooling with it?

If it works, don't fix it...