Subsonic 223 rounds, load listings in Hodgdon manual

[crracer_712]

I bought the Hodgdon Reloading manual (the magazine with CFE223 on the cover). I was browsing through the 223 Remington section and was really disappointed in that the only 55 grain bullet listed was for a subsonic load, in three different powders. I would have thought with the popularity of the 55 grain bullet, there would have been a lot offered in this area.

Looking at the Subsonic load data, it listed one of the powders I have, titegroup. For the load, it showed 3.1 grains. Really? I believe this was to output at 1064 FPS.

Has anyone ever loaded subsonic in 223?

I load my .380 ACP with titegroup at 2.9 grains, that's a tiny amount. I was having a hard time figuring how that tiny amount would push the bullet out of a 16" barrel. I'd think 3.1 grains could end up with granuals end to end and stretch from the base to the neck, not stacked up. How would this ever give reliable and consistent burn rates?

 

[kingmt]

Really.

Yes.

The primer lights it.

 

[Owen]

using that small amount of fast powder in that long, long barrel (for 3,1gr. of TG) you don't really need consistent burn rate, it will all average out.

 

[kingmt]

Why would you not need it to be consistent? The powder would probably be burnt before the bullet got to the rifleing.

 

[Owen]

right, so if its all burned, and generating full pressure by the time the bullet gets to the rifling, you are going to see much velocity variation.

it the measurement of the powder was accurate, the area under the pressure time , and pressure distance curve are going to be very consisntent, making the integral of those curve (pound-seconds, aka impulse or momentum) and (pound-ft aka work or energy). very consistent.

 

[kingmt]

Please teach this. You may have to talk down to me a bit tho since I'm no ballistic expert & I have no idea what you just said.