.243 win

josh29j · December 27, 2016, 09:16 PM

I just got hornadys bullet comparator and headspace guage. So I went through and sized my case .001-.002 back from what my fired brass measure. Werid part is I had to set up die like normal I didn't need to back the die off any. Normal? But the real question is I want to load .02,.015,.01,.005 off my lands. Do I need to reduced my powder charge from what I was previously shooting? If so how much? I was not at the max thanks. I reload alot of pistol I only ever load for my .243 in rifle

SARuger · December 27, 2016, 10:12 PM

Is your new COAL longer or shorter than your current COAL? If your setting the bullets deeper you need to start at min and work up until you see pressure signs. Running those rounds through a chronograph isnt a bad idea either

Regardless, when you make a change, you need to work the load up again to be safe and find the sweet spot.

josh29j · December 27, 2016, 10:36 PM

My old coal was 2.640 my new would be 2.670 up to 2.685

SARuger · December 27, 2016, 11:00 PM

I'm no expert but I would do a load work up at each bullet seating depth. Not so much for safety, but for accuracy, unless your current load is near or at max

josh29j · December 27, 2016, 11:11 PM

I'm not at max

T. O'Heir · December 28, 2016, 01:11 PM

Off-the-lands has nothing to do with the powder charge. It's a load tweaking technique that can be done after you've worked up the load. Every chamber is different, so every rifle will like a different distance off the lands with every bullet weight.
Or you can forget about it altogether. It doesn't make enough difference to matter for a hunting rifle.
You adjust the OAL, by trail and error, after finding where the lands start using the load you've already worked up. Not a different load at every distance. Think in terms of working up a load with one thou's OAL difference from 2.640" to 2.685". That'd be 45 different loads to work up.
"...Weird part..." One or 2 thou isn't enough to matter or notice.

**Unclenick** · December 28, 2016, 01:30 PM

Josh,

A bullet touching or slightly wedged into the lands can produce about 20% more pressure than it does backed off about 0.030" (the numbers vary with the bullet design). A 10% load reduction will give you around 20% less pressure with many rifle powders, so take a load you know is safe in that gun and drop it 10%, even if that takes you below a book starting load, as a starting point for touching the lands. When you tune the charge weight for best accuracy with the bullet touching the lands, then test different seating depths with that load. If you find one that produces a tighter group, you can go through tweaking the charge wight over again for that new amount of jump to shrink the groups further.

reynolds357 · December 30, 2016, 05:01 PM

Seating the bullet deeper reduces pressure.

CarJunkieLS1 · December 30, 2016, 06:22 PM

If your using a hunting rifle just start them at max mag length and do a powder charge work up. Find your most accurate powder charge and if results need to be better adjust seating depth .010 at a time. By starting at max mag length you only have onee way to go.

December 27, 2016, 09:16 PM	#1
josh29j Member Join Date: December 28, 2014 Posts: 63	.243 win I just got hornadys bullet comparator and headspace guage. So I went through and sized my case .001-.002 back from what my fired brass measure. Werid part is I had to set up die like normal I didn't need to back the die off any. Normal? But the real question is I want to load .02,.015,.01,.005 off my lands. Do I need to reduced my powder charge from what I was previously shooting? If so how much? I was not at the max thanks. I reload alot of pistol I only ever load for my .243 in rifle

December 28, 2016, 01:11 PM	#6
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	Off-the-lands has nothing to do with the powder charge. It's a load tweaking technique that can be done after you've worked up the load. Every chamber is different, so every rifle will like a different distance off the lands with every bullet weight. Or you can forget about it altogether. It doesn't make enough difference to matter for a hunting rifle. You adjust the OAL, by trail and error, after finding where the lands start using the load you've already worked up. Not a different load at every distance. Think in terms of working up a load with one thou's OAL difference from 2.640" to 2.685". That'd be 45 different loads to work up. "...Weird part..." One or 2 thou isn't enough to matter or notice. __________________ Spelling and grammar count!

December 28, 2016, 01:30 PM	#7
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Josh, A bullet touching or slightly wedged into the lands can produce about 20% more pressure than it does backed off about 0.030" (the numbers vary with the bullet design). A 10% load reduction will give you around 20% less pressure with many rifle powders, so take a load you know is safe in that gun and drop it 10%, even if that takes you below a book starting load, as a starting point for touching the lands. When you tune the charge weight for best accuracy with the bullet touching the lands, then test different seating depths with that load. If you find one that produces a tighter group, you can go through tweaking the charge wight over again for that new amount of jump to shrink the groups further. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

December 27, 2016, 10:12 PM	#2
SARuger Senior Member Join Date: October 11, 2014 Location: Blue Ridge Mountains of VA Posts: 954	Is your new COAL longer or shorter than your current COAL? If your setting the bullets deeper you need to start at min and work up until you see pressure signs. Running those rounds through a chronograph isnt a bad idea either Regardless, when you make a change, you need to work the load up again to be safe and find the sweet spot.

December 27, 2016, 10:36 PM	#3
josh29j Member Join Date: December 28, 2014 Posts: 63	My old coal was 2.640 my new would be 2.670 up to 2.685

December 27, 2016, 11:00 PM	#4
SARuger Senior Member Join Date: October 11, 2014 Location: Blue Ridge Mountains of VA Posts: 954	I'm no expert but I would do a load work up at each bullet seating depth. Not so much for safety, but for accuracy, unless your current load is near or at max

December 27, 2016, 11:11 PM	#5
josh29j Member Join Date: December 28, 2014 Posts: 63	I'm not at max

December 30, 2016, 05:01 PM	#8
reynolds357 Senior Member Join Date: December 10, 2012 Posts: 6,165	Seating the bullet deeper reduces pressure.

December 30, 2016, 06:22 PM	#9
CarJunkieLS1 Senior Member Join Date: October 1, 2013 Posts: 686	If your using a hunting rifle just start them at max mag length and do a powder charge work up. Find your most accurate powder charge and if results need to be better adjust seating depth .010 at a time. By starting at max mag length you only have onee way to go.