06-13-2023, 01:13 AM
I'm trying to work up a load for my Howa Mini (20" HB) using 123 SST's and CFE223. This Mini is my 3rd Grendel (I also had 24" and 16" AR's) and I have never been able to get CFE223 to agree with me...
This rifle shoots my trusty 90 TNT/H335 load sub-MOA (the top 6 shot group is a new batch that I loaded at the same time as the 2.248 and 2.245 COL SST loads, the bottom 4 were an old batch of the 90's)
[ATTACH=CONFIG]19804[/ATTACH]
But I shot through a box of 123 SST's with CFE223 and my groups ALL look like shotgun patterns...
[ATTACH=CONFIG]19805[/ATTACH]
I thought I was doing everything right, I've always kind of loaded haphazardly but I did this workup a little more strategically... Shot 15 rounds in .2gr increments, found the flat spot in the velocities. Shot 5 round groups at the charge weights that yielded the flat spot and got a single digit SD right in the middle at 30.6gr.
[ATTACH=CONFIG]19806[/ATTACH]
Then I started trying to dial a COL, started at 2.260 because I had to start somewhere, and worked my way down in .003" increments to 2.245" and didn't get a group better than 1.5".
Thoughts? Should I use the rest of the box to go up in length? My Howa has a Jefferson Outdoors BDL style floorplate and 2.3" fits into the magazine but I figured I should try to run shorter rather than longer for more reliable feeding.
Is my process not sound? The SD/ES of this load is significantly better than the 90 TNT load and all the manuals put the COL right in the 2.245-2.25ish range.
Does my Howa just not like 123 SST's, or CFE223? That would be hard to understand, although the 24" Brownells barrel and the 16" Faxon Barrel I have haven't shot CFE 223 either...
The rest of the recipe is:
Several times fired Hornady brass, torch annealed
CCI 450
Charges thrown with a powder measure and trickled to finish
This rifle shoots my trusty 90 TNT/H335 load sub-MOA (the top 6 shot group is a new batch that I loaded at the same time as the 2.248 and 2.245 COL SST loads, the bottom 4 were an old batch of the 90's)
[ATTACH=CONFIG]19804[/ATTACH]
But I shot through a box of 123 SST's with CFE223 and my groups ALL look like shotgun patterns...
[ATTACH=CONFIG]19805[/ATTACH]
I thought I was doing everything right, I've always kind of loaded haphazardly but I did this workup a little more strategically... Shot 15 rounds in .2gr increments, found the flat spot in the velocities. Shot 5 round groups at the charge weights that yielded the flat spot and got a single digit SD right in the middle at 30.6gr.
[ATTACH=CONFIG]19806[/ATTACH]
Then I started trying to dial a COL, started at 2.260 because I had to start somewhere, and worked my way down in .003" increments to 2.245" and didn't get a group better than 1.5".
Thoughts? Should I use the rest of the box to go up in length? My Howa has a Jefferson Outdoors BDL style floorplate and 2.3" fits into the magazine but I figured I should try to run shorter rather than longer for more reliable feeding.
Is my process not sound? The SD/ES of this load is significantly better than the 90 TNT load and all the manuals put the COL right in the 2.245-2.25ish range.
Does my Howa just not like 123 SST's, or CFE223? That would be hard to understand, although the 24" Brownells barrel and the 16" Faxon Barrel I have haven't shot CFE 223 either...
The rest of the recipe is:
Several times fired Hornady brass, torch annealed
CCI 450
Charges thrown with a powder measure and trickled to finish