357 mag Heavy Loads

[runfiverun]

2400 is a favorite for colder temps here too.
blue dot is affected by the cold as is h-110, and 4227 is inconsistent in the heat.
another powder to consider is 800-x it needs to be weighed individually but does well in temp swings.
also sr-4756 is a good powder ,i use it for deer hunting in my 45 colt with horn xtp's and 250 rnfp cast.
it meters very good and is pretty consistent in velocity.

i used to shoot my 357's quite a bit at distance, and i had cut out some steel silhouette's.
i was able to consistently hit these with 38 cases 4 grs of 231 and 158 swc's at a blazing velocity of @800 fps.
oh yeah the distances were from 20 feet to over 300 yds.
kinda like, bang.............................................. .........................tinggggk.
keep things over or under sonic the whole way, and look at the design for stability.
that will help more than pure velocity,and the things [problems] you need to make velocity work.

[trelly]

Also bear in mind that the twist rate for your revolver is optimized for 125 to 158 grain bullets. Those 180's will spread more because they are not fully stabilized in that barrel.

In mikeb82301's above post he makes this comment. Where do you find this information (twist rate optimized for 125 to 158 grain bullets)?

I'm picking up my 45-70 tomorrow and would like to get into reloading for it. The twist rate factor is new to me.

Can someone give an explanation?

[runfiverun]

search for the greenhill formula it is based on the length of the bullet.
you can get a heavier bullet to stabilize by speeding it up.
it takes more pressure to do this
or by using a faster twist in the bbl.
this will affect lighter bullets, by over spinning them at high velocity.

thats why some rifles like heavy and some like light bullets.
for instance most of your 308 and 30-06 rifles use a 1-10 twist.
just because someone might want to shoot a 200 or 220 gr bullet in them.
most of your 30-30, and some 308/30-06 rifles use a 1-12 twist.
and most often a 150 or 170 gr bullet is used.

for your 45-70 just go with 405 gr and you can't go wrong.

[Pegasus1]

The 405's work great in my 45-70 too.

[trelly]

Thanks for the info. Helped answer some other questions I've had.