Seating Consistancy

38spl · September 21, 2002, 03:01 PM

I am having trouble getting a consistant seating length when reloading 223 rem on my new rockchucker. Every time I think I have it set correctly, the next few I seat are way off. For example, I set the die to seat at 2.250 and for a few rounds I will get this. Then I will get a 2.235, then a 2.240, then a 2.254. What am I doing wrong? Is it unreasonable for me to think I will get the same seating depth every time? I realize I may be off from the 2.250 depth a couple hundreths, but not what I am getting. I am very careful to take the same stroke of the handle every time and to make sure the bullet is straight in the case before I pull the handle. The cases are all trimmed to the exact same lenght and the cases are all winchester cases. The only thing I can think of is that I am using the cheap 55 gr FMJ winchester bullets just until I go through the whole process of reloading a few times. Then I will get better bullets. I have been reloading for my handguns for quite some time on a Dillon SDB and have never had this problem. I never thought that this would be one of my problems when using the rockchucker. Any advice y'all can give me would be grealty appreciated. Thanks in advance for your help.

WESHOOT2 · September 21, 2002, 07:23 PM

Might try changing seating die stem (the part that pushes the bullet).

swifter... · September 21, 2002, 10:07 PM

Are you measuring from the bullet tip to the casehead? That may be your problem. Many bullets -- even match grade -- are inconsistent in their lengths. You may need a Stoney Point gadget, or some other form of comparator to get a more accurate measurement from casehead to ogive. You probably aren't much off, really.

Tom

labgrade · September 22, 2002, 01:00 AM

I'd betcha swifter's close to the mark.

As a quick experiement, measure a couple dozen different bullets & note their variance in length. May be surprised.

OAL is properly set & measured, for any specific firearm (rifles especially), to the ogive. That said, I never have used an ogive comparator.

Too, sometimes you can get junk build-up on your seating stem & it can compress at various rates giving you strange seating depths. Good idea to clean it once in a while.

Poodleshooter · September 23, 2002, 11:02 AM

Leave the seating stem alone, and just seat them w/o checking OAL after your initial setup. Consistency is the key. As mentioned, get a Stoney Point if you want to adjust for bullet jump.

Steve Smith · September 23, 2002, 02:19 PM

"Are you measuring from the bullet tip to the casehead? That may be your problem. Many bullets -- even match grade -- are inconsistent in their lengths. You may need a Stoney Point gadget, or some other form of comparator to get a more accurate measurement from casehead to ogive. You probably aren't much off, really.
Tom"

BINGO! We have a winner!

Take some of your bullets and measure them from base to tip. if the differences are large enough to account for your cartridge's OAL variance, there you go. If not, then you're having a problem with something moving. My bet is that your bulets are not consistent.

As you know, I shoot with a .223 competitively, almost every week. We in the match communty are well aware of irregular bullet tips. The bullet manufacturers have found that the tips have very little to do with accuracy. A much more important part is the ogive to base measurement. The better bullets will be much more consistent here because it matters.

So, you'll get better bullets and then your problem will go away, right? Wrong!

Like I said, the tips are inconsistent on match bullets too. You have to think about what's pushing them down into the case. match quality seaters don't push on the tip, but rather they push against a place much closer to the ogive. The Redding and the Forster Ultra are two very popular types that do this. Using one of these seater dies, you'll have much more consistent seating depths, despite irregular tips.

BUT.

If you do this, then ALL of your seating measurements must change to ogive measurements, with exception of the mag-length criteria. Find one of the longest bullets in your box, seat it so that it will be under the 2.260" for .223, take the ogive-to-case head measurement with a Stoney Point OAL guage, write it down, and from then on, that is your "OAL" using the Stoney Point unit. Use that to set your new Redding or Forster seating die, and you're set.

labgrade · September 24, 2002, 12:55 AM

Would appear that we have a concensus.

FWIW, The best I've ever seen in bullet length consistency was with Nosler's Ballistic Tips - any caliber. Seems that polycarbonate tip has much to do with bullet OAL repeatability, yada. I'd assume that Horn's VMax would be in the same ballpark. Not that the bullet is any better, but that the tip is.

Doesn't appear that the ogive tangent-to-base is (or could be) the "problem" (as then we'd have these things flying all over the place), but more a function of the final tip forming process which gives some funky COAL readings through strandard measuring methods.

There's some wisdom to be had here.

Even though your COAL (measured with calipers, let's say) isn't anywhere close to what you'd expect match grade ammo to be, more than likely, your OAL, at the ogive is. You just need a slightly differnt measuring device to be able to see it is all.

Betcha most stuff is closer than what we see through "standard measuring practices."

38spl · September 24, 2002, 05:42 AM

Thanks for all of the help everyone. I have certainly been enlighted in the measuring of COL. I did not know that the true COL measurement was taken from the ogive.

Steve, I took your advice and simply found the longest bullet and seated it to fit into my mag ( 2.250 ), locked the die in and began to load. I will be ordering one of the bullet comparators from Sinclair soon so I can get better readings for seating depth.

Thanks again for your all y'alls help!

Steve Smith · September 24, 2002, 09:03 AM

Was why I started grabing the longest bullet in the box.

In Highpower you shoot either two or four strings (depending on the match) of rapid fire. In between strings I was loading magazines and found that some of my cartridges were to long. Knowing that I was using a top quality seater, I knew that it was the tip that was making the difference. The somewhat longer round went on top of the mag, and I adjusted my dies when I went home.

Bogie · September 24, 2002, 12:22 PM

The best gizmo for checking OAL to the ogive is the little 6-sided nut that Sinclair sells.

Rmouleart · September 25, 2002, 12:28 PM

I read the thread and noticed no one asked if you where trimming your brass to size or using new brass, I have noticed even with new brass is not trimmed to the same size the are just off a little but thats all it takes when seating to spec, I trim all my brass to size first, this really makes getting your OAL easy,Sometimes its the little things we forget to do that causes us havoc, just my thoughts, hope this helps. Aim small hit small. RAMbo.

labgrade · September 25, 2002, 06:00 PM

COAL or COL is actually the overall length of the cartridge & in a perfect world, would be measured to the bullet tip. But the ogive is the functional point for length.

Don't see where trimmeing brass would make any difference in COAL. Bullet may have more/less inside the neck, but length is length. If you crimp, nevermind, as that will have an affect - just not on COAL.

September 21, 2002, 03:01 PM	#1
38spl Junior Member Join Date: August 24, 2001 Location: PA Posts: 10	Seating Consistancy I am having trouble getting a consistant seating length when reloading 223 rem on my new rockchucker. Every time I think I have it set correctly, the next few I seat are way off. For example, I set the die to seat at 2.250 and for a few rounds I will get this. Then I will get a 2.235, then a 2.240, then a 2.254. What am I doing wrong? Is it unreasonable for me to think I will get the same seating depth every time? I realize I may be off from the 2.250 depth a couple hundreths, but not what I am getting. I am very careful to take the same stroke of the handle every time and to make sure the bullet is straight in the case before I pull the handle. The cases are all trimmed to the exact same lenght and the cases are all winchester cases. The only thing I can think of is that I am using the cheap 55 gr FMJ winchester bullets just until I go through the whole process of reloading a few times. Then I will get better bullets. I have been reloading for my handguns for quite some time on a Dillon SDB and have never had this problem. I never thought that this would be one of my problems when using the rockchucker. Any advice y'all can give me would be grealty appreciated. Thanks in advance for your help.

September 21, 2002, 07:23 PM	#2
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	DON'T KNOW RIFLES, BUT............ Might try changing seating die stem (the part that pushes the bullet). __________________ . "all my ammo is mostly retired factory ammo"

September 21, 2002, 10:07 PM	#3
swifter... Senior Member Join Date: March 16, 1999 Location: So. CA Mountains Posts: 540	Are you measuring from the bullet tip to the casehead? That may be your problem. Many bullets -- even match grade -- are inconsistent in their lengths. You may need a Stoney Point gadget, or some other form of comparator to get a more accurate measurement from casehead to ogive. You probably aren't much off, really. Tom __________________ There are damn few situations so screwed up that adding government to them will not make 'em worse... The best homeland security is an armed & informed citizenery! Molon Labe!

September 23, 2002, 02:19 PM	#6
Steve Smith Senior Member Join Date: December 9, 1999 Posts: 4,131	"Are you measuring from the bullet tip to the casehead? That may be your problem. Many bullets -- even match grade -- are inconsistent in their lengths. You may need a Stoney Point gadget, or some other form of comparator to get a more accurate measurement from casehead to ogive. You probably aren't much off, really. Tom" BINGO! We have a winner! Take some of your bullets and measure them from base to tip. if the differences are large enough to account for your cartridge's OAL variance, there you go. If not, then you're having a problem with something moving. My bet is that your bulets are not consistent. As you know, I shoot with a .223 competitively, almost every week. We in the match communty are well aware of irregular bullet tips. The bullet manufacturers have found that the tips have very little to do with accuracy. A much more important part is the ogive to base measurement. The better bullets will be much more consistent here because it matters. So, you'll get better bullets and then your problem will go away, right? Wrong! Like I said, the tips are inconsistent on match bullets too. You have to think about what's pushing them down into the case. match quality seaters don't push on the tip, but rather they push against a place much closer to the ogive. The Redding and the Forster Ultra are two very popular types that do this. Using one of these seater dies, you'll have much more consistent seating depths, despite irregular tips. BUT. If you do this, then ALL of your seating measurements must change to ogive measurements, with exception of the mag-length criteria. Find one of the longest bullets in your box, seat it so that it will be under the 2.260" for .223, take the ogive-to-case head measurement with a Stoney Point OAL guage, write it down, and from then on, that is your "OAL" using the Stoney Point unit. Use that to set your new Redding or Forster seating die, and you're set. __________________ Favor the X. Steve Smith NRA Life Member

September 24, 2002, 09:03 AM	#9
Steve Smith Senior Member Join Date: December 9, 1999 Posts: 4,131	What I didn't tell you... Was why I started grabing the longest bullet in the box. In Highpower you shoot either two or four strings (depending on the match) of rapid fire. In between strings I was loading magazines and found that some of my cartridges were to long. Knowing that I was using a top quality seater, I knew that it was the tip that was making the difference. The somewhat longer round went on top of the mag, and I adjusted my dies when I went home. __________________ Favor the X. Steve Smith NRA Life Member

September 22, 2002, 01:00 AM	#4
labgrade Member In Memoriam Join Date: November 29, 1999 Location: west of a small town, CO Posts: 4,346	I'd betcha swifter's close to the mark. As a quick experiement, measure a couple dozen different bullets & note their variance in length. May be surprised. OAL is properly set & measured, for any specific firearm (rifles especially), to the ogive. That said, I never have used an ogive comparator. Too, sometimes you can get junk build-up on your seating stem & it can compress at various rates giving you strange seating depths. Good idea to clean it once in a while.

September 23, 2002, 11:02 AM	#5
Poodleshooter Senior Member Join Date: August 7, 2000 Location: Floating down the James River in VA Posts: 2,599	Leave the seating stem alone, and just seat them w/o checking OAL after your initial setup. Consistency is the key. As mentioned, get a Stoney Point if you want to adjust for bullet jump.

September 24, 2002, 12:55 AM	#7
labgrade Member In Memoriam Join Date: November 29, 1999 Location: west of a small town, CO Posts: 4,346	Would appear that we have a concensus. FWIW, The best I've ever seen in bullet length consistency was with Nosler's Ballistic Tips - any caliber. Seems that polycarbonate tip has much to do with bullet OAL repeatability, yada. I'd assume that Horn's VMax would be in the same ballpark. Not that the bullet is any better, but that the tip is. Doesn't appear that the ogive tangent-to-base is (or could be) the "problem" (as then we'd have these things flying all over the place), but more a function of the final tip forming process which gives some funky COAL readings through strandard measuring methods. There's some wisdom to be had here. Even though your COAL (measured with calipers, let's say) isn't anywhere close to what you'd expect match grade ammo to be, more than likely, your OAL, at the ogive is. You just need a slightly differnt measuring device to be able to see it is all. Betcha most stuff is closer than what we see through "standard measuring practices."

September 24, 2002, 05:42 AM	#8
38spl Junior Member Join Date: August 24, 2001 Location: PA Posts: 10	Thanks for all of the help everyone. I have certainly been enlighted in the measuring of COL. I did not know that the true COL measurement was taken from the ogive. Steve, I took your advice and simply found the longest bullet and seated it to fit into my mag ( 2.250 ), locked the die in and began to load. I will be ordering one of the bullet comparators from Sinclair soon so I can get better readings for seating depth. Thanks again for your all y'alls help!

September 24, 2002, 12:22 PM	#10
Bogie Senior Member Join Date: June 5, 2000 Location: Job hunting on the road... Posts: 3,827	The best gizmo for checking OAL to the ogive is the little 6-sided nut that Sinclair sells. __________________ Job hunting, but helping a friend out at www.vikingmachineusa.com - and learning the finer aspects of becoming a precision machinist. And making the world's greatest bottle openers!

September 25, 2002, 12:28 PM	#11
Rmouleart Senior Member Join Date: September 24, 2002 Location: NH Posts: 141	I read the thread and noticed no one asked if you where trimming your brass to size or using new brass, I have noticed even with new brass is not trimmed to the same size the are just off a little but thats all it takes when seating to spec, I trim all my brass to size first, this really makes getting your OAL easy,Sometimes its the little things we forget to do that causes us havoc, just my thoughts, hope this helps. Aim small hit small. RAMbo.

September 25, 2002, 06:00 PM	#12
labgrade Member In Memoriam Join Date: November 29, 1999 Location: west of a small town, CO Posts: 4,346	COAL or COL is actually the overall length of the cartridge & in a perfect world, would be measured to the bullet tip. But the ogive is the functional point for length. Don't see where trimmeing brass would make any difference in COAL. Bullet may have more/less inside the neck, but length is length. If you crimp, nevermind, as that will have an affect - just not on COAL.