COAL and CBTO Factory vs. Reloads

[paulleve]

I received my TSUSA 1k case of Winchester .223 a few days ago and was curious how these $.27 rounds would compare to my reloads in terms of consistent overall length (COAL) and base to ogive (CBTO) measurements. These results were interesting, so I then checked some Hornady (50 round box) and Creedmoor Sports ammo. For each type of ammo I measured 10 random rounds and recorded results:



The Winchester rounds had the most variation in CBTO, coming in at .023 from least to greatest! My reloads come in at $.35 with a 55 grain Hornady FMJBT oiver H335. Last time I was out shooting groups I put ten of these rounds into 1.35" at 100 yards, which seems pretty good for what they are! I'm looking forward to trying the Winchester at the 100 to see just how much impact the loose tolerances have on accuracy.

The Hornady 50 pack was more consistent than the Winchester, but still had a .008" variation in CBTO. The winner of the day was the batch of Creedmoor Sports I measured. These used to be sold through CMP, and during the early days of quarantine when no one had ammo, I bought multple cases of this stuff for $.65 per round shipped. I've gotten some great accuracy out of these rounds, and it's no question as to why with this level of consistency!

 

[EddieZoom]

Nice deep dive analysis...thanks for sharing.

 

[Mountain]

I received my TSUSA 1k case of Winchester .223 a few days ago and was curious how these $.27 rounds would compare to my reloads in terms of consistent overall length (COAL) and base to ogive (CBTO) measurements. These results were interesting, so I then checked some Hornady (50 round box) and Creedmoor Sports ammo. For each type of ammo I measured 10 random rounds and recorded results:

View attachment 799123 View attachment 799124

The Winchester rounds had the most variation in CBTO, coming in at .023 from least to greatest! My reloads come in at $.35 with a 55 grain Hornady FMJBT oiver H335. Last time I was out shooting groups I put ten of these rounds into 1.35" at 100 yards, which seems pretty good for what they are! I'm looking forward to trying the Winchester at the 100 to see just how much impact the loose tolerances have on accuracy.

The Hornady 50 pack was more consistent than the Winchester, but still had a .008" variation in CBTO. The winner of the day was the batch of Creedmoor Sports I measured. These used to be sold through CMP, and during the early days of quarantine when no one had ammo, I bought multple cases of this stuff for $.65 per round shipped. I've gotten some great accuracy out of these rounds, and it's no question as to why with this level of consistency!

Very good post. I'm also a fan of Creedmoor Sports ammo, especially the ammo they make from Lapua components. If I'm a little behind on match reloads I can grab a box of Creedmoor .

Next step down the rabbit hole is checking your reloading projectiles for consistency. Bergers are always GTG but of the others lately I am liking Nosler CC's and RDF's.

 

[xtry51]

Nosler seems like the best from my experience on bulk .223, but I normally use Hornady.

Wolf has done OK as well for 55gr bulk bullets if you're making training ammo.

I also keep even my 55gr reloads at 2.250 COAL. I have way better accuracy results keeping them max mag length.

 

[Mountain]

Nosler seems like the best from my experience on bulk .223, but I normally use Hornady.

Wolf has done OK as well for 55gr bulk bullets if you're making training ammo.

I also keep even my 55gr reloads at 2.250 COAL. I have way better accuracy results keeping them max mag length.

Agreed on maximum mag length for accuracy. Also some of the high BC bullets are not the most accurate at mag length. I have found standard Berger BT's to be more accurate at mag length for the 6ARC AR than the ELD bullets. ELD's have too big of a jump to the lands. Haven't found any Hybrids to try just yet.

 

[paulleve]

I tried some of the Winchester .223 rounds in my Ruger Predator at the 100 yard range today. Two five shot groups measured 1.93" and 2.35". (That 2.35" group included the highest and lowest CBTO measured rounds in the table from the first post.) Just to make sure I wasn't having a bad day, I shot a string of 77 grain SMK handloads, which resulted in a group slightly over .75". So it looks like the Winchester ammo is about 2 MOA range fodder, maybe better if someone wants to measure and sort them. There are some random rounds in the target pic so I circled the actual groups.

 

[xtry51]

Factory ammo is basically trash all around unfortunately and totally unreliable batch to batch. I've see the full gambit of 4moa 62gr Lake City to 1moa Wolf steel case. Even Black Hills used to be like magic 10-15 years ago. Bought some 5 years ago and it was 100% trash. Haven't bought more since.

 

[akma]

Agreed on maximum mag length for accuracy. Also some of the high BC bullets are not the most accurate at mag length. I have found standard Berger BT's to be more accurate at mag length for the 6ARC AR than the ELD bullets. ELD's have too big of a jump to the lands. Haven't found any Hybrids to try just yet.

My target 223 won't fit in the mag.

 

[xtry51]

I limit all my reloads to max mag length (whether 223 or .308). I can still make sub moa ammo with this self-imposed limitation. Nodes just become important.