Converting foreign powders to Somchem?

[deleted] 2 years ago

Hi Folks,

I have to convert loads from 4227, H110 and Win 296 to S265.

How does one proceed?

Note: it is still for the .410-2". I have found loads on US and GB forums and would like to make sure I dont damage a beautiful old shotgun.

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OA oafpatroll

Why not just start with somchems own load data and work from there?

https://www.somchemreload.com/search?c=12&f=294

[deleted] OP

Why not just start with somchems own load data and work from there?

https://www.somchemreload.com/search?c=12&f=294

Somchem's loads are for 65mm cases.

I need to load for a 51mm case.

The original load was 163gr (⅜oz) of shot with xyz amount of black powder.

On the forums I have found following, and similar:

" ... typically 6 grains of Bullseye, 7 grains of Unique, 8 grains of Herco, 15 grains of #2400 or 17 grains of 4227 ... "

These are - as far as I could determine - spherical and flake powders, even though their burn speeds are close to S296.

4227, H110 and Win296 are said to be the closest to S265.

It would be stupid to guess a load.

OA oafpatroll

Why not just start with somchems own load data and work from there?

https://www.somchemreload.com/search?c=12&f=294

Somchem's loads are for 65mm cases.

I need to load for a 51mm case.

The original load was 163gr (⅜oz) of shot with xyz amount of black powder.

On the forums I have found following, and similar:

" ... typically 6 grains of Bullseye, 7 grains of Unique, 8 grains of Herco, 15 grains of #2400 or 17 grains of 4227 ... "

These are - as far as I could determine - spherical and flake powders, even though their burn speeds are close to S296.

4227, H110 and Win296 are said to be the closest to S265.

It would be stupid to guess a load.

Aha, sorry I missed your reference to the shell length. You can't cause a kaboom in a shotty with birdshot loaded pap so I'd start at half the somchem charge (shot and propellant) and see what it does for you. If you find specs for commercial 2 inch ammo you could use that as a guide/target for shot weight and velocity.

TR Tripodmvr

Ter verduideliking. Data verkry met 22 KHornet om 'n verwysing te kry. Druk is op 10000 psi beperk. Hopelik sal dit 'n beter idee gee van die brandtempo's en verhouding tussen die vier dryfmiddels. Volgens hierdie is daar min verskil tussen die ladings.

Powder type Filling/Loading Ratio 1.Charge Charge Vel. Prop.Burnt P max 2.Charge Vel.
% Grains Gramm fps % psi Grains fps

Winchester 296 50,5 6,6 0,43 1619 60,9 10000 5,9 1465
Hodgdon H4227 58,5 6,5 0,42 1600 58,6 10000 5,9 1482
Hodgdon H110 50,0 6,6 0,43 1587 64,6 10000 5,9 1436
Somchem S265 57,7 6,5 0,42 1552 65,2 10000 6,0 1423

[deleted] OP

BAIE BAIE DANKIE OOM DRIEPOOT!!!

Uiteindelik het ek rustigheid. Nou kan die kinders gaan skiet.