454 Casull charge guidance 340gn

[RB98SS]

Gentlepersons,

I'm looking for some help with Casull charges. Specifically with a 340gn bullet that has two crimp groves. I currently have a couple loads with 2400 and H110 that are around 1100 fps and shoot well. These loads have an OAL of 1.750 and are crimped in the lower groove. I am having some rounds on occasion that jump the groove and jam the cylinder so I'd like to crimp on the upper groove. This will put the bullet 1/10" deeper in the case. Any suggestions as to what amount I should back the charges off to stay safe? I've looked as best I can to find 340gn load data but all of the data I can find is for the longer OAL. The charges I'm currently using are 2400 - 21.0 and H110 - 23.5 + 25.0.

Any help would be greatly appreciated

 

[black mamba]

My double crimp groove 340 gr bullet loads to 1.67 in the forward groove, and should give about 1125 fps in a 5½" barrel with 18.0 gr of 2400. This is a pretty mild load at only 33 kpsi. 20.8 gr. at this OAL should give about 1285 fps @ 50 kpsi. With H110 my program shows 22.0 gr. giving 1135 fps @ 31.5 kpsi, and 25.4 gr. giving 1325 fps @ 50 kpsi.

 

[RB98SS]

Thanks for the info. That seems right looking at my load data. Are these loads you have used or is the information you provided from Quickload or some other ballistic software?

Anyway, thank you again.

 

[black mamba]

Both, but my program is Gordon's Reloading Tool, which is a free download off the net. Well worth looking into.