Match ammo ballistics

[Ptbirshooter87]

Different companies, different platforms, but I am under the impression that ammo companies used to use 26-28" barrels for testing back when longer barrels were in style. Now that shorter barrels are in vogue they're testing with slightly shorter. Federal uses 24" barrels for their testing, per the emails we traded back and forth. I wouldn't be surprised if Winchester is using a 20-24" to test their 223 ammo.

I was reading a bunch of different info most of which was third party input and that’s where the 20” came into play. I appreciate all the help this should be a good starting point.

 

[Jcann]

Like @swampratt said. Gather your amount of drop from a target (100, 200, 300, 350, 400, .....) with a 100 yard zero. Shoot at the same spot at all ranges. From the amount of drop from these different ranges you tune your muzzle velocity in your ballistic app to correspond with the data collected from your target. Don’t concern yourself too much with the wind or horizontal stringing; you’re looking at differences in elevation. Hopefully you’re a moa or better shooter.

I believe the bullet Winchester is using is the 69gr Sierra Matchking which has a G7 ballistic coefficient of 0.165 (taken from Applied Ballistic App); Note, generally when using boattail bullets use a G7 BC. A G1 BC is used for flat based bullets.

 

[HoLeChit]

I received this back from Winchester:

Subject: Winchester.com - Contact Inquiry

Submission Date: 2/21/2021 4:09:26 PM

Question: In regards to your 223 Remington, 69 Grain Match S223M2 loads, I was wondering what barrel length you tested it out of, and if you guys had any expectations in regards to performance numbers out of a 16" AR platform barrel?

Answer:

This product was tested and data was genereated with 24 inch test barrels. I use this product regularly in AR's with 16 and 20 inch barrels. The 16 inch AR will shoot around .75 inch groups at 100 yards. My 20 inch bull barrel target rifle shoots .50 inch groups, both rifles have a 1:8 Twist.



Best Regards,



D. Ballard

Winchester

didn’t get expected velocities out of the platform, but I’m guessing it’s safe to say what other guys have, where you can subtract 25-35fps loss in velocity per inch of barrel length lost.