9mm bullet question

[offthepaper]

Going to start loading for my CZ75B.
I've bought some bullets, a box of Frontier 147gr.
The box is marked..."CMJ Swagged, 9mmP, 147gr RN"

My question is, are these considered a Jacketed bullet, or copper plated bullet.

The difference in powder load would be significant.
The Jacketed bullet (using Accurate #5) would be between 4.8gr to 5.3gr max.

The Copper plated bullet (also using Accurate #5) would be 4.0 gr to 4.4 gr.

Advice appreciated.

 

[rfwobbly]

Hey, that's great news !!

Yes, the CMJ is a metal jacketed bullet, so you'd use the jacketed data for 147gr.

Some additional thoughts.....
• The CZs are noted for their very short freebore. This means that the CZ barrel does not easily digest every bullet on the market. Some extended work may be needed to find your OAL. You may not be able to use the book OAL.

• There's more detailed help on reloading for CZ on the CZ Forum

• 147's sit deep inside the case. If you are forced to a foreshortened OAL, then you have to watch that there's enough room for the powder.

All the best

 

[noylj]

I have never had any trouble with COL with my CZ75s. However, I also never pay any attention to the minimum recommended COL in the manual as I do my set-up with my barrel in hand and work for the longest COL that fits the magazine and feeds and chambers. I always start with the start load or a few tenths below start (in 9x19 and .40S&W--very COL sensitive cartridges).
I would NOT start with such a heavy weight bullet, and 9x19 loading must be done with care.
Verify that, after chambering an inert "dummy" round a couple of times, that bullet set-back is no more than 0.002". Any bullet set-back over 0.007" can raise pressure to dangerous levels.
Do not repeatedly chamber a round as it will start to suffer bullet set-back no matter how good the case/bullet tension is.

 

[Hondo 60]

CMJ = Complete Metal Jacket

 

[GLOOB]

A jacketed bullet has the jacket formed first, then the lead is poured in. This leaves exposed lead on one end. Complete Metal Jacket is a misnomer, which I thought actually meant it was plated??