how to determine if subsonic

[olympicmotors]

Mas:

You have mentioned several times on this forum to make sure to use supersonic rounds in the 155 - 165 grain 40 caliber Speer Gold Dots.

I do not have access to a chronograph , I just thought all the gold dot rounds were standardized and the only difference in them was the grain.

My box says:

Speer LE
Gold Dot
duty ammunition
40 S&W 165 GR. GDHP
53970

This is a 50 round box I purchased online from ammunitiontogo.com

How do I know if these are the full power rounds?

I was carrying 180 grain but have switched to the 165 as per your recommendation.

Thanks

[Mas Ayoob]

Product code for the Speer Gold Dot 165 grain .40 S&W in full power loading (1140-1150 foot seconds nominal velocity) is 23970. Speer is not currently listing a 165 grain subsonic in the Gold Dot series.

best,
Mas