bullet depth - Page 2

Marty · 01-23-2006, 07:21 AM

For target shooting I allways seat my projectiles so they are just touching the lands or slightly off maybe a few thousands of an inch. I find good accuracy this way but in repeating rifles there may be feeding problems and the cartridges may not fit the magazine. Loads need to be slightly reduced if the bullet is touching the lands as it does change the time/pressure curve and can be dangerous with hot loads.

rdale501 · 02-10-2008, 07:27 PM

Sorry to bring all of this up again, but after all of this time I have solved my problem, almost by accident. While reading my Barnes reloading manual, I came accross a procedure where you take a brass fired in your gun and smoke the seating shoulder. Next you set up the sizing die to barely touch the brass. Checking it in the bore after each adjustment, you turn the sizing die down into the press, until there is a visable bright ring in the smoked shoulder. At this point the sizing die is adjusted to resized the brass to fit the chamber. I did not have any fired brass so I loaded up 5 and took them to the range just to fire them for the brass. I randomally chose 49.5 grains of IMR4350 and loaded 85 grain Nosler bullets. The Nosler manual lists this as most accurate with this powder. I seated the bullets to the recomended depth and trimed the brass to the recommended length. I put 4 of the 5 in a clover shaped hole with the 5th a called flyer about 1". I couldn't believe it. After all I have been through with this gun, I found a good load by trying to do something else. Thought you guys might be interested, At least be excite for me, it's been a long road.

Deersniper · 02-10-2008, 07:53 PM

What lefty o said, and each size of ammo must be measured, as they differ. Each rifle is different You tune with load, and fine tune with OAL. I stay 10 to 30 off according to the bullet. 168's like 10, 165's like 15,while 150's like 20 in my rifle.

turkn8r1 · 02-12-2008, 12:04 AM

I am with the others but my magic numbers have been between 30 and 50 thousandths off the lands.

lefty o · 02-12-2008, 12:15 AM

dale, you've discovered neck sizing, well poor mans version. i prefer to use an actual neck sizing die, but the results are pretty much the same. be aware that after a few firings, you will have to full length size that brass.

rdale501 · 02-12-2008, 01:01 PM

Quote:

Originally Posted by lefty o

dale, you've discovered neck sizing, well poor mans version. i prefer to use an actual neck sizing die, but the results are pretty much the same. be aware that after a few firings, you will have to full length size that brass.

Lefty, I think you are right--this is a form of neck sizing. I have a neck sizing die for this round, and have used it. The point I was making is I have done everything I can think of to make this gun shoot; I ran accross this procedure in my Barnes manual and was going to give it a try, figuring what to heck can't hurt. I never actually put it to use. I full sized some remington brass and picked out a random load of IMR4350, just to get some brass to start this procedure with. Low and behold the random load I chose was dead on in this gun. Purely by accident, I get to claim no credit for working this round up. Oh well, I guess i'll still shoot it.

lefty o · 02-12-2008, 01:39 PM

better to be lucky than good. sometimes!

runfiverun · 02-12-2008, 10:01 PM

from lightly kissing the lands to way back every rifle has a sweet spot
just remember the further in you go the more case you are using up

runfiverun

SL11 · 02-13-2008, 08:59 AM

rdale 501,

If you can find a copy of Handloader magazine No.251 (February '08), you can read a nice article on pages 65 - 69 about the seating depth effects one guy found for his .223 Remington. He ended up with 0.020" off the lands as his best COL. But, that is not the important information from the article, because different bullets in different rifles may have different "sweet spots." The article will give you a good idea of how to study the effect in your rifle and how much variation in group sizes is caused by bullet position compared to how much is just random from group to group with the same cartridge dimensions.

With respect to your loss of accuracy beyond 50 yards with the 120 grain bullets in Remington factory loads: that sounds like it might be a stability problem with a bullet length near the upper limit of stability for your rifling twist. If so, it might help to push it a little faster. Factory loads are not noted for being particulary high velocity (not usually up to advertised velocities). A different bullet of the same weight that is a little shorter might also help. But, if it is a stability problem, going down to 115 grain bullets should help a lot more.

SL11

01-23-2006, 07:21 AM	#21
Marty Member Join Date: Jan 2006 Location: Newcastle, Australia Posts: 16	For target shooting I allways seat my projectiles so they are just touching the lands or slightly off maybe a few thousands of an inch. I find good accuracy this way but in repeating rifles there may be feeding problems and the cartridges may not fit the magazine. Loads need to be slightly reduced if the bullet is touching the lands as it does change the time/pressure curve and can be dangerous with hot loads.

02-10-2008, 07:27 PM	#22
rdale501 Senior Member Join Date: Sep 2007 Location: oregon Posts: 398	Sorry to bring all of this up again, but after all of this time I have solved my problem, almost by accident. While reading my Barnes reloading manual, I came accross a procedure where you take a brass fired in your gun and smoke the seating shoulder. Next you set up the sizing die to barely touch the brass. Checking it in the bore after each adjustment, you turn the sizing die down into the press, until there is a visable bright ring in the smoked shoulder. At this point the sizing die is adjusted to resized the brass to fit the chamber. I did not have any fired brass so I loaded up 5 and took them to the range just to fire them for the brass. I randomally chose 49.5 grains of IMR4350 and loaded 85 grain Nosler bullets. The Nosler manual lists this as most accurate with this powder. I seated the bullets to the recomended depth and trimed the brass to the recommended length. I put 4 of the 5 in a clover shaped hole with the 5th a called flyer about 1". I couldn't believe it. After all I have been through with this gun, I found a good load by trying to do something else. Thought you guys might be interested, At least be excite for me, it's been a long road.

02-10-2008, 07:53 PM	#23
Deersniper Senior Member Join Date: Mar 2006 Posts: 1,688	What lefty o said, and each size of ammo must be measured, as they differ. Each rifle is different You tune with load, and fine tune with OAL. I stay 10 to 30 off according to the bullet. 168's like 10, 165's like 15,while 150's like 20 in my rifle.

02-12-2008, 12:04 AM	#24
turkn8r1 Senior Member Join Date: Jan 2008 Location: Southern Mississippi Posts: 144	I am with the others but my magic numbers have been between 30 and 50 thousandths off the lands.

02-12-2008, 12:15 AM	#25
lefty o Senior Member Join Date: Mar 2002 Location: mn Posts: 4,806	dale, you've discovered neck sizing, well poor mans version. i prefer to use an actual neck sizing die, but the results are pretty much the same. be aware that after a few firings, you will have to full length size that brass.

02-12-2008, 01:39 PM	#27
lefty o Senior Member Join Date: Mar 2002 Location: mn Posts: 4,806	better to be lucky than good. sometimes!

02-12-2008, 10:01 PM	#28
runfiverun Senior Member Join Date: Jan 2008 Location: soda springs idaho Posts: 288	from lightly kissing the lands to way back every rifle has a sweet spot just remember the further in you go the more case you are using up runfiverun

02-13-2008, 08:59 AM	#29
SL11 Member Join Date: Nov 2007 Posts: 85	rdale 501, If you can find a copy of Handloader magazine No.251 (February '08), you can read a nice article on pages 65 - 69 about the seating depth effects one guy found for his .223 Remington. He ended up with 0.020" off the lands as his best COL. But, that is not the important information from the article, because different bullets in different rifles may have different "sweet spots." The article will give you a good idea of how to study the effect in your rifle and how much variation in group sizes is caused by bullet position compared to how much is just random from group to group with the same cartridge dimensions. With respect to your loss of accuracy beyond 50 yards with the 120 grain bullets in Remington factory loads: that sounds like it might be a stability problem with a bullet length near the upper limit of stability for your rifling twist. If so, it might help to push it a little faster. Factory loads are not noted for being particulary high velocity (not usually up to advertised velocities). A different bullet of the same weight that is a little shorter might also help. But, if it is a stability problem, going down to 115 grain bullets should help a lot more. SL11