First of all, thanks for taking the time to read my thread. I have been reloading pistol for a little over a year and have just started reloading for my .223, with the hopes of someday reloading for .308 long distance. I have loaded and chrono-ed a few times to get a somewhat consistant FPS. Now I want to try and get the COL right with my rifle. How much off the lands should I start at, and do I try and work it closer? Is there a ideal distance or is this something that is specific to each and every rifle? Again thanks for looking and any help with this is greatly appreciately.
.223 COL
- Thread starter ragwd
- Start date
Nope. All guns are a law unto themselves in this regard.
Be aware that pressure goes up when the bullet is either put too close to or touches lands or when you seat a bullet so deeply that it uses up too much powder space. So, a load you've developed for standard COL can be unsafe with the bullet much deeper or much further out.
I recommend you drop your load 15% and work it back up in small (.3 grain) steps with the bullet actually touching the lands. When that load is at its best, you will have a charge safe at all the seating depths you try. It will probably be about 8-10% lower than your standard load. Then you incrementally increase the seating depth. I use 0.010" increments as I have seen steps that small make a difference. I go down until the bullet bearing surface is at least one caliber (.224" for the .223) into the case mouth or slightly more if that doesn't put the ogive down into the case mouth.
Read Dan Newberry's round robin method for finding powder charge and substitute changing seating depth for changing powder charge to locate your gun's favorite seating depth with the bullet you chose. Be aware this depth often changes with bullet ogive form. For example, Walt Berger says that after recommending throat contact for his VLD designs for years, they determined they actually shoot better about 0.090" to 0.150" off the lands (depending on the gun), IIRC? Many shorter ogives want to be closer to the throat than that. You see people swear by touching the lands, 0.005" off the lands, 0.010" off the lands, 0.015" off the lands, 0.020" off the lands, 0.030" off the lands, etcetera, etcetera.
In the Precision Shooting Reloading Guide, one of the authors describes how he accidentally turned the micrometer head on his seating die the wrong way one day and wound up seated bullets too deeply; about 0.050" off the lands instead of 0.020" that he usually used and thought was best. He had 50 rounds loaded before he noticed the error and debated pulling and re-seating them, but decided to shoot these "defective" rounds in practice instead. To his surprise, they shot better in his rifle than any other load he'd ever worked up for it.
Be aware that pressure goes up when the bullet is either put too close to or touches lands or when you seat a bullet so deeply that it uses up too much powder space. So, a load you've developed for standard COL can be unsafe with the bullet much deeper or much further out.
I recommend you drop your load 15% and work it back up in small (.3 grain) steps with the bullet actually touching the lands. When that load is at its best, you will have a charge safe at all the seating depths you try. It will probably be about 8-10% lower than your standard load. Then you incrementally increase the seating depth. I use 0.010" increments as I have seen steps that small make a difference. I go down until the bullet bearing surface is at least one caliber (.224" for the .223) into the case mouth or slightly more if that doesn't put the ogive down into the case mouth.
Read Dan Newberry's round robin method for finding powder charge and substitute changing seating depth for changing powder charge to locate your gun's favorite seating depth with the bullet you chose. Be aware this depth often changes with bullet ogive form. For example, Walt Berger says that after recommending throat contact for his VLD designs for years, they determined they actually shoot better about 0.090" to 0.150" off the lands (depending on the gun), IIRC? Many shorter ogives want to be closer to the throat than that. You see people swear by touching the lands, 0.005" off the lands, 0.010" off the lands, 0.015" off the lands, 0.020" off the lands, 0.030" off the lands, etcetera, etcetera.
In the Precision Shooting Reloading Guide, one of the authors describes how he accidentally turned the micrometer head on his seating die the wrong way one day and wound up seated bullets too deeply; about 0.050" off the lands instead of 0.020" that he usually used and thought was best. He had 50 rounds loaded before he noticed the error and debated pulling and re-seating them, but decided to shoot these "defective" rounds in practice instead. To his surprise, they shot better in his rifle than any other load he'd ever worked up for it.
Thanks UncleNick, seems like a lot to digest. I knew that if you shorten the col it causes a pressure increase but I didn't know that if the bullet is either put too close to or touches lands that it would also increase the pressure. thanks for the link and picture. I will read the link by Newberry.
There has been several about this "head spacing" lately. I have read and re read all of these threads as I am new to reloading for necked cartridges. The thing I have learned lately is that once you have full length sized your cartridge and then shot in your rifle, you don't necessarily want to full size again but to just neck size to maintain the fire formed to your rifle. Do I have that right ? If so, then what about this quote taken from "lee precision" talking about their collet dies.
Quote These dies size only the neck to preserve the perfect fit of fire forming. Only reload cases that have been fired in your gun. Not recommended for autoloaders, slide or lever action guns. Unquote
Not recommended for auto loaders??? Does this mean don't bother for my Ar 15? Any thoughts here?
Also another interesting idea I have read lately, and reading is great but it doesn't come close to real life experience. So I am asking for thoughts on this next quote also. This is taken from the link provided by UncleNick http://optimalchargeweight.embarqspace.com/#/ocw-instructions/4529817134
Quote The seating depth for all test loads should of course be the same. I normally seat the bullet a caliber's depth into the case, or to magazine length--whichever is shorter. I don't believe loading to approach the lands is necessary, or even desirable in most situations. So long as the bullets are seated straight, with as little runout as possible, the advantages of loading close to the lands are largely over-stated. This said, be certain that the seating depth you choose does not cram the bullet into the lands. Stay at least .020" or so off the lands for these excercises. unquote
I included the whole paragraph, so not to take this out of context, but the part that really hits me is
I don't believe loading to approach the lands is necessary, or even desirable in most situations. So long as the bullets are seated straight, with as little runout as possible, the advantages of loading close to the lands are largely over-stated. ???????
Now this guy has one heck of a nice web site and really seems to know. So is this head spacing or loading to the lands a moot point ?
Again I am new and learning so if I am all wrong, my apologies.
Quote These dies size only the neck to preserve the perfect fit of fire forming. Only reload cases that have been fired in your gun. Not recommended for autoloaders, slide or lever action guns. Unquote
Not recommended for auto loaders??? Does this mean don't bother for my Ar 15? Any thoughts here?
Also another interesting idea I have read lately, and reading is great but it doesn't come close to real life experience. So I am asking for thoughts on this next quote also. This is taken from the link provided by UncleNick http://optimalchargeweight.embarqspace.com/#/ocw-instructions/4529817134
Quote The seating depth for all test loads should of course be the same. I normally seat the bullet a caliber's depth into the case, or to magazine length--whichever is shorter. I don't believe loading to approach the lands is necessary, or even desirable in most situations. So long as the bullets are seated straight, with as little runout as possible, the advantages of loading close to the lands are largely over-stated. This said, be certain that the seating depth you choose does not cram the bullet into the lands. Stay at least .020" or so off the lands for these excercises. unquote
I included the whole paragraph, so not to take this out of context, but the part that really hits me is
I don't believe loading to approach the lands is necessary, or even desirable in most situations. So long as the bullets are seated straight, with as little runout as possible, the advantages of loading close to the lands are largely over-stated. ???????
Now this guy has one heck of a nice web site and really seems to know. So is this head spacing or loading to the lands a moot point ?
Again I am new and learning so if I am all wrong, my apologies.
wncchester
New member
"Now this guy has one heck of a nice web site and really seems to know. So is this head spacing or loading to the lands a moot point ?"
The guy knows what he's talking about.
Seating depth is a signficant factor in accuracy.
The bullet's seating depth is independant of "headspace".
The guy knows what he's talking about.
Seating depth is a signficant factor in accuracy.
The bullet's seating depth is independant of "headspace".
Unclenick is giving excellent advice (as usual). When loading for accuracy, I generally start with a mid-range load and bullets seated .010" off the lands, then work the load up .5 gr at a time until I find the best powder charge, then fiddle with seating depth to fine tune (some bullets like to be up against the rifling, others like to be backed off). This generally gets me in the area of the most accurate loads.