Can anyone recommend starting loads for 450gr FN Cast and 450gr FN-FMJ. Can I use either IMR4198 or IMR3031?
Charlie-NY> Guess my real concern in starting to develop a new load is always the same. That is, without knowing a recommended Starting Load (for a particular bullet), we're left with the chance of not knowing if our "guess" is a good Starting Load, or, is it a (dangerous) reduced load? I firmly agree that "smaller charges of faster burning powder" are a good general rule if you know that you must deal with less case room due to developing that new load with a heavier bullet (your 425gr vs my 450gr). Or, even worse, if the new bullet has a FMJ (versus a Cast bullet).Heavy lead bullets take up a lot of room in the case. This leaves less room for powder and makes smaller charges of faster burning powder a good choice. I often use 4198 for this reason.
Charlie-NY> Here's what I don't understand. You went to the faster 4198... from (the slower) 3031... bcs 4198 needs less powder. Yet, both you and Crusty Deary Ol Coot both use H335 which is slower than 3031 ?Hodgdon's Reloading data list 28gr-32gr of H4198 for a 485gr bullet. These are trapdoor loads that don't exceed 20K CUP. If you are shooting a Marlin even 32gr would be a very light load.
You could easily start at 32gr and get comfortable with your rifle and reloads. It should get you about 1,500 ft/sec. You will have plenty of room for growth if you want it.
CDOC has more experience with the 465gr cast bullet than anyone I know. Both him and O29 recommended H335. That would be good enough for me.
Personally, I'm sold on jacketed bullets and Barnes monos, so what do I know. LOL
You misread my comments. I use H4198 because it has worked well for me and it has low volume. It is possible for some powders to be too bulky to fit beneath heavy lead bullets, depending on the charge weight. H4198 has always shot great for me with both lead and jacketed bullets. It also works well IMO with light and heavy bullets in the 45-70.Charlie-NY> Here's what I don't understand. You went to the faster 4198... from (the slower) 3031... bcs 4198 needs less powder. Yet, both you and Crusty Deary Ol Coot both use H335 which is slower than 3031 ?
I am assuming your loading for a Marlin rifle, so I'll go from there.
I shoot a RUGER, so have plenty of head room/safety margin but I still faced the same confusion when first beginning to develop loads for my rifle.
But something that helped me a lot is this thought, ANYTHING listed for a Springfield Trapdoor from a reputable source will be safe in your Marlin.
So, if you don't already, get yourself a copy of the 4th addition Lyman Cast Bullet Handbook in which you will find LOTS of Trapdoor data from which to start. They list data for bullets from 292gr up to 540gr, ten different bullet weights in total, including the 450gr.
Then any data you find for a "jacketed" bullet of 450gr +/- would be safe with a cast bullet !
I'm shooting a 465gr Wide Flat Nose cast at 1650fps, using 47.5gr of H335 in my RUGER.
If using a WFN cast, you don't need warp velocity to get er done, in fact early in my 45/70 experience I used a 355gr at a muzzle velocity of 2300fps and NEVER AGAIN want to see that big of a wound channel!!!!!!!!!! The heavier bullet at a much slower velocity is just soooo much better in a number of ways and has for me, accounted for a growing pile of deer and 3 elk.
I'll agree that load data for the Marlin is LACKING!!!!!!!!!!!!!!!!!! in and around your selected bullet weight, some which I am at a loss to understand considering that I have cycled my loads in a through Marlins with zero problems. I have NOT test fired my loads in that rifle.
Crusty Deary Ol Coot