Subsonic ammo question

[compuvette]

I have a full-size IMI model A RR on the way to me along with a Coastal suppressor. I was wondering if 147gr JHP rounds would still be subsonic out of the UZI's 10" barrel? They are out of my MAC10/9mm with Coastal can, just wondering about the extra barrel length. Thanks!

 

[KarlPMann]

Most likely yes. But it does increase the velocity a little to come from a 10" barrel instead of a 4" barrel. If the round was barely subsonic, it may become supersonic in the 10" barrel of your UZI. If so, just drop .1 grains from the load and you'll be OK. Karl.

 

[compuvette]

Cool. P.S. Happiness is a hot silencer!

 

[Mario_FAMOInc]

They should be.
Marginally subsonic loadings could go sonic with more barrel length. Some subsonic loadings will go sonic if left in the sun on a hot day.
I load my own to be sure of the results.
Mario