Jacketed data for cast bullet

[Buddro]

In my quest to get a 255 grain gas checked hard cast swc going around 1250 down my 8 3/8 inch barreled smith and wesson model 29-2 I am running into a bind.
I have only a few powders available right now, a little bit of unique, w231 and a 4 pounder of Vitavhuouri n340. I'm trying to source some 2400, if it was good enough for Elmer its good enough for me. But in these times getting ahold of powder isn't too easy.

My lyman book has some recipes for unique pushing 1100 fps out of a 4 inch barreled gun. Maybe I would get up to 1250ish in my 8 inch barreled gun but I don't really want to try with such a fast burning powder if I can avoid it.

This is where the n340 comes into play. Vitavhuori lists a load for a 250 grain jacketed bullet getting 1213 out of a 7 inch barrel. I hate the idea of using data that doesn't match my materials exactly but things are starting to look desperate. Obviously starting at base data and working up how would those of you who are more experienced with cast bullets feel about using 250 grain jacketed data for a 255 grain gas checked bullet?

[Bloodman14]

As I understand it, you can use starting jacketed data as a good starting point for cast, given the same firearm. The friction will be less, the pressures a tad lower and the velocity will increase slightly. This has been my experience in rifles, I only load for .45 ACP in pistols. I have NO experience with Vitavhuori powders, don't use them. Hopefully, those with more experience will chime in and be of more assistance.

[Rainier]

Hodgdon (Winchester) has data for the 44 Magnum and W231 powder using a 240gr LSWC and 270gr GoldDots in an 8.2 inch barrel.

For the 240gr LSWC they start at 5.5gr (800 fps) and go up to 11.0gr (1334 fps)

For the 270gr SPR GDSP they start at 8.0gr (992 fps) and go up to 10.0gr (1194 fps)

I suspect you can work up to the velocity you want or at least get close to it with W231.

Also, 2400 is a fantastic powder but don’t shy away from W296/H110 if you run across any.

Good Luck!

[gwpercle]

I can't find any data for cast / n340 either ... it's start low and work up slowly .

Data for cast I do have shows H110 , 2400 , 296 and Accurate #9 to be likely to get the velocity done , Accurate #9 looks very promising ... keep your eyes open and call local dealers often ...
When mine know I am looking for powders , they call / email when they get a shipment ...
get on their mailing list .
I'm hoping supply will soon catch up to demand .
Gary

[Buddro]

H110 was on my radar but being as the early 29s aren't necessarily the most robust guns out there I want to keep my pressures down. A load in the velocity range I want to be in would be on the lighter side of things for H110 powder and I read it doesn't really like to be loaded down. If I find a 1 pounder I will probly grab it and try it anyways (loads that burn dirty in some guns may burn great in my gun) but it doesn't look ideal. I read 2400 may get me to the mid 1200s without fussing as much. I have got a list of alternative powders on my phone in case I stumble over anything in the stores.

[Winger Ed.]

In years gone by, I'd thought that if you weren't living out on the edge--- you were taking up too much room.

However; in later years, I've changed that out look a little.
In this case:
I'd be careful about going into uncharted waters by just using jacketed powder data for cast.
The tendency will be to start low, but depending on the powder--- you might get also into a zone where detonation can happen.

And that could get real exciting.

[ShooterAZ]

First off, welcome to the forum! I would not hesitate for a second to use the VV N340 in the cast boolit 44 Mag loads. Start out at the minimum load for your bullet weight (10 grains), and work up like always. In my opinion VV powders are second to none. The 250 grain data should be fine with a 255 grain boolit, however I will always strongly advise against starting out with a max load.

[Burnt Fingers]

As I understand it, you can use starting jacketed data as a good starting point for cast, given the same firearm. The friction will be less, the pressures a tad lower and the velocity will increase slightly. This has been my experience in rifles, I only load for .45 ACP in pistols. I have NO experience with Vitavhuori powders, don't use them. Hopefully, those with more experience will chime in and be of more assistance.

In many cases cast boolits give a HIGHER pressure than jacketed bullets with the same powder charge.