Please define the term, “max loadings”.
Cast, powder-coated and gas-checked can be slung out at remarkable velocities, depending on the alloy composition.

 

Please define the term, “max loadings”.
Cast, powder-coated and gas-checked can be slung out at remarkable velocities, depending on the alloy composition.

Max loadings is the listed maximum loading in published data. Minimum means lowest and maximum means highest.

 

Up front, I'm not an expert when it comes to cast. I've looked into coated cast bullets for my carbines and what I am finding is that powder coated and Hi-Tek coated cast bullets are safe up to 2300fps, read it on the net so it must be true. LOL

Supposedly, flat base cast bullets that are coated, 1 to 2 thou over bullet diameter, appropriate hardness, do not need to be GC'd. From what I have gathered certainly not at carbine velocity but have read that includes 30-30 velocities. When cast bullets are properly coated, whether powder coat or Hi-Tek, the coating is the jacket. They should be oversized as well as flat base bullets and you're good to go.

Some people still GC with coating but many folks are running non-GC coated bullets with no leading. Do your research and there is a lot of info available including YT video's regarding this.

FWIW, I'm going to be trying coated bullets in my carbines this year with no GC and hoping it works out.

Jack

 

Powder coated and gas checked stand up in my 35 rem. 2100fps. I got away from it because the bullet is a bore rider and nose sizing is a pain in the butt.

 

Are we talking coatings for jacketed or cast?

 

I think we are talking powder coated but the thread is not clear. Moly coated jacketed would obviously work OK at all speeds.

 

If this is about cast the second question would be is this for paper punching or hunting. It makes a difference not because of the coating but because of the bullet profile and alloy.

If you are casting and coating your own for hunting bullet profile and alloy is the concern. I've pushed BLL to around 2400 fps with no or little loss of accuracy. With a good powder coating like smoke4320's up to over 2600 fps. But at that speed and my twist rate with a flat point I will get major fragmentation. You have to go with a high speed alloy with babbitt introduced for the bullet to survive impact. And that is a whole new game there in casting

 

Do you have any specific bullet weight you favor? Any specific powder manufacturer or data source? Does your chosen source specify coated or coated/gas checked projectiles? Jacketed bullet max and cast/coated max can vary, sometimes by a significant amount. The pressure curve for jacketed and cast is very different, the bullets act differently in the bore. Deformation is obviously different.

Cast/coated/GC bullets reach the same velocity as jacketed with less powder because they have a lower coefficient of friction. There are so many variables, the data may not interchange.

 

I got to thinking about the question the OP posed for a couple hours. If I had to give a specific answer or advice it would be this. Cast bullets favor the faster burning propellants, so find some IMR 4198, IMR 3031, Reloder 7, or Accurate 2230. Go with the starting charge for a jacketed bullet using your choice cast,coated/GC bullet of equal weight. Work up until max velocity listed for jacketed in the data is achieved with your cast bullet. Do not exceed maximum powder charge listed, and of course keep a close eye on accuracy. This is where the chronograph is absolutely necessary. Load development outside of published data is an area some people won't tread. There's always unforeseen dangers. Plus, cast diameter, alloy, gas check, and coating are all wild cards.

If the accuracy goes away, reduce the powder charge until good groups return, and that is the MAX for the specific bullet/powder combo in that firearm.