How to correctly measure my load

[TopperT]

Back again with a question.  I am shooting a 38-55.  my first loads badly "keyholed".   Now I have the right bullet and wad but I wonder about correctly measuring each load.
In my muzzelloaders I "threw" 70 grains more or less into the barrell and fired away.  This is way more technical.  How do you get such fine measurements as +/- a grain or two when the 'standard' is volume?...How do you make the transition from volume to weight?
If anyone has a 38-55 load they'd love to share I'll try it out asap.
Thanks...... :cb2:

[Cuts Crooked]

dat's easy pard! Ya jist take yer powder measure fulla the charge yer gonna use... 'n dump it onto yer scales! Then you'll know the weight prezactly! :wink:

[Don in PA]

Jim
I'll tell you how I start up a load.
1- Find the Cartridge OverAll Length (COAL) with the bullet just touching the rifling. Call this "0" jump
2- Fill the case with enough powder plus wad so that with about .060" compression the bullet will just seat on the wad when you have the above COAL.
Don't use the bullet to compress the load get a compression die.
Test the load. If your very lucky the load works if not the fun begins.
Start changing things, for example:
Increasing powder with same COAL ... you are increasing the veloicity, of cause, but your also increasing compression.
Same powder charge with .020" jump (ie seat the bullet .020" off the rifling) ... your keeping the same velocity but increasing the compression.

Just keep trying until you get the accuracy you need.
When you make changes, try to change only one element at a time, ie. the COAL or the compression, primer, powder ect.
Generaly Goex needs more compression then Swiss, Don't know about the other brands of BP.
Don

[Don in PA]

Jim
I got a little carried away with the my reply. When you determine that first load as described in 1 and 2 above weigh the load. That's your starting load.
Don