After the first shoots with my new Rossi 1892 24" in .44mag, I want now to find the best combination for accuracy. I tried 240 SWC + GC bullets and Lee 310gr + GC. The 240gr was made with 50% lead 50%linotype so BHN15; and the .310gr with 2,75%antimony and 5%tin so BHN14.
The accuracy was better with the .310gr. Under the bullet was 1,35g (20,8gr) of french powder SP3 (equivalent of H4227).
I know that now I have to test different loads with different powders, but I would like also test different alloys.
As I am not fan of very hard bullets, I would like to test, mainly for the .310gr bullet which is slower in the barrel, a 1:10 tin alloy with BHN11. It is quite soft for magnum cartridge, but my feeling is that with a 30" switch rate barrel, it can work (I already got very nice groups with this alloy for the .375win).
What do you thing? Is it worth testing it?
Thanks!

Definately worth testing. What is your bore diameter? Despite internet lore, bullet/bore diamnter are far more important than hardness when it comes to cast bullets.

I didn't make precise measurement yet. I will do it. Normally the Rossi bore diameter is around 0.429"
My bullets were sized at 0.430", which is the most recommended diameter for .44 mag cast bullets.
But, I need to measure it, because maybe 0.431" could work better in my barrel....?
However, with softer bullets, if my bullets are too small in diameter, the softness of the bullet should be able to help in order to get a good closing of the barrel...

Lafayette,

Definately try the .431" bullet. In cast bullets, a bullet diameter difference of .002" can make cause a six inch (15 cm) 100 yard group to shrink down to 0.75 inches (2 cm).

If you haven't read Marshall's articles on the 444 Marlin in the Tech Notes

( http://www.beartoothbullets.com/tech_notes/index.htm) you'll find them well worth reading!

Thanks El lobo. Indeed, I need to try the .431, I can maybe improve my groups.
Of course, I already have the .430 and the .432 sizer, not the .431! So I will buy it. I will have to order it directly from a US web seller, as in France Saeco is not an easy brand to find!
This week-end, I tried to measure the bore diameter, but it was not easy. I saw that I almost was able to enter the bullet in the bore just pushing hard with my finger. But the grooves are really not deep.
Anyway, the tests done this week-end are quite clear:
- at 50m (55y), with 1/10 tin bullet, BHN11, 310gr Lee => group is 6,5"x5,5"...:(
- at 50m, with BHN14 alloy (2,75% Antimony, 5%tin), 310gr Lee => group is 1"x1,5":cool:

So, definitivly, the Rossi barrel don't like too soft bullet.
Now, playing with the load, and the bullet size, I will try to get better group, and then shoot at 100meters...

Definately worth testing. What is your bore diameter? Despite internet lore, bullet/bore diamnter are far more important than hardness when it comes to cast bullets.
I agree. By the way my Rossi Puma .44 Mag barrel slugs at .432" so when I cast my own, I need to make sure they come out at least .432" and preferrably larger. If I shoot .429" bullets I get lots of barrel leading.

I'll definitely try to push a lead round ball in the barrel in order to get a precise measure of the bore diameter. what surprised me si that I was able to push a .430 bullet in the bore. So, OK the grooves are really thin but....
I was thinking that .431 is the right size, but finally maybe the .432 will be OK...?

One question: is there any risk (overpressure...) if I shoot with an oversized bullet (for instance .432 for a .429 barrel)? Thanks.

Hey guys, you know what: I made the round bullet test and the result for the bore diameter is: .432!! That's what we can call an oversized barrel....
So, I will use my .432 lubrisizer. But working with big bullets is not so good for many reasons:
- the crimping of the gas check is not so efficient
- Some bullet mould are nor oversized: for example my .310gr Lee give .431 bullets!

But, from now, these .310gr bullets gave the best result in accuracy (1"x1,5"), so I will continue to test it!