What velocities would be considered underpowered when it comes to .223 / 5.56?
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What velocities would be considered underpowered when it comes to .223 / 5.56?
Velocity and port pressure are not directly related.
The powder burn rate can affect cycling greatly.
Hodgdon data from 2001, but shows pressure vs. Velocity.Attachment 62723
I’m asking in reference to internal ballistics not terminal ballistics. I was just wondering after I observed a tuned gun fail to lock back a bolt while firing PMC bronze, and it made me wonder if that ammo is considered “underpowered” especially it’s posted velocity on the box is like 2900 FPS.
To answer that you would need to find out the minimum velocity threshold of the particular projectile you are using.
An example would be; Speer Gold Dot 5.56MM 75 grain will penetrate and expand at a minimum of 1800 FPS. I made those numbers up because I don’t use that type of projectile/ammo.
Speer Gold Dot is a good example, I don't think they even make a 5.56 load because it uses a bullet tailored to perform better at .223 velocity, same with the Federal Fusion bullet, you actually degrade performance if you push it too fast.
But to the OP's question in regards to PMC Bronze that round does have a rep for being underpowered.