Working up load for new .223

Lilswede1 · April 3, 2010, 09:22 AM

New to me (used) CZ .223 Bolt.
Need to review procedure for working up a good shooting load.
Brass all prepped and ready.
Have some tools ie, Honady Headspace gage, OAL gage etc.
Will be loading 2230 powder using a Blitzking 50 gr. bullet.
Whats your procedure from this point.

**Unclenick** · April 3, 2010, 01:51 PM

Read Dan Newberry's OCW load site for the best systematic method of load workup I know of currently. I find 2230 a little slow for best accuracy with bullets under 55 grains. H4198 or IMR4198 or Reloader 10X are my preferred powders for 50 grain bullets. 2230 should positively be avoided for 40 grain bullets because of secondary pressure readings (see the RSI plot, below). Using heavier bullets or faster powder eliminates those spikes.

When I used Accurate 2520 one year in my M1A for match shooting, I found its performance improved dramatically when I began deburring flash holes. That extra step never made any visible difference for me with stick powders in that gun, but spherical propellants are harder to ignite. It cut my groups from 1.25 moa to 0.7 moa in that gun by adding the deburring step with 2520. I understand from subsequently reading this article on primers, that going to magnum primers might have achieved the same advantage because the percent case fill was not great with my load? I didn't try it at the time. 2230 seems a bit less sensitive to this, but I think that's because it fills the case better than the 2520 load I used in the .308. Nonetheless, I've subsequently deburred flash holes for 2230 without testing the necessity, just because it is spherical.

On your OAL gauge: You'll find Newberry eschews non-basic equipment and still gets 1/2 moa groups. I find the OAL gauge and concentricity gauges and fancy gear seems to matter with some chambers and bullets a lot more than others. About a 5:1 difference for concentricity from what I've seen. In your shoes, since you have a gauge and are looking for peak accuracy, I would adopt Newberry's round robin method to seating depth first. That is, take a low starting load (so you don't get excess pressure when the bullet touches the lands), then use that same load for a round robin of seating depths from land touching all the way back to full seating of the leading edge of the bullet bearing surface flush with the case mouth. I do this in 0.020" steps, looking for what the gun wants with the particular bullet (and this does vary with the bullet)? I then repeat in 0.005" steps between the two best groups from the first round robin. These are not usually spectacular groups with a random light starting load. I am just looking for some evidence to tell me where the bullet should be seated while I do the powder workup?

April 3, 2010, 09:22 AM	#1
Lilswede1 Senior Member Join Date: September 8, 2008 Location: NW Wash State Posts: 216	Working up load for new .223 New to me (used) CZ .223 Bolt. Need to review procedure for working up a good shooting load. Brass all prepped and ready. Have some tools ie, Honady Headspace gage, OAL gage etc. Will be loading 2230 powder using a Blitzking 50 gr. bullet. Whats your procedure from this point.

April 3, 2010, 01:51 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Read Dan Newberry's OCW load site for the best systematic method of load workup I know of currently. I find 2230 a little slow for best accuracy with bullets under 55 grains. H4198 or IMR4198 or Reloader 10X are my preferred powders for 50 grain bullets. 2230 should positively be avoided for 40 grain bullets because of secondary pressure readings (see the RSI plot, below). Using heavier bullets or faster powder eliminates those spikes. When I used Accurate 2520 one year in my M1A for match shooting, I found its performance improved dramatically when I began deburring flash holes. That extra step never made any visible difference for me with stick powders in that gun, but spherical propellants are harder to ignite. It cut my groups from 1.25 moa to 0.7 moa in that gun by adding the deburring step with 2520. I understand from subsequently reading this article on primers, that going to magnum primers might have achieved the same advantage because the percent case fill was not great with my load? I didn't try it at the time. 2230 seems a bit less sensitive to this, but I think that's because it fills the case better than the 2520 load I used in the .308. Nonetheless, I've subsequently deburred flash holes for 2230 without testing the necessity, just because it is spherical. On your OAL gauge: You'll find Newberry eschews non-basic equipment and still gets 1/2 moa groups. I find the OAL gauge and concentricity gauges and fancy gear seems to matter with some chambers and bullets a lot more than others. About a 5:1 difference for concentricity from what I've seen. In your shoes, since you have a gauge and are looking for peak accuracy, I would adopt Newberry's round robin method to seating depth first. That is, take a low starting load (so you don't get excess pressure when the bullet touches the lands), then use that same load for a round robin of seating depths from land touching all the way back to full seating of the leading edge of the bullet bearing surface flush with the case mouth. I do this in 0.020" steps, looking for what the gun wants with the particular bullet (and this does vary with the bullet)? I then repeat in 0.005" steps between the two best groups from the first round robin. These are not usually spectacular groups with a random light starting load. I am just looking for some evidence to tell me where the bullet should be seated while I do the powder workup? __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; April 3, 2010 at 01:58 PM.