Jimbo51 wrote:Ok thanks everyone the cartridges are S&B .303, powder is APS 450, projectiles are HRBC 180gn 311, the rifle was a Sparbrook 1906 not sure of the number of groves or the twist of this rifle The thinking was that as I was hitting the target sideways I needed more powder.
But as I have learnt more is not the way to go.
the first loads I did with out a gas check when using a check the round would not chamber all way so have pulled them and re neck sized the cases awaiting ideas.
Maybe just bin the twenty cases and start with new ones.
Thanks for you assistance.
Hey when you wrote that you started with 32gns of 2206H I knew you were talking rifle.
The drop to 10gn pistol powder is, I am guessing a try at reduced velocity loads.
A sideways bullet is a classic sign of a projectile that is unstable and projectiles are unstable, usually, when the rotational velocity is too low for the bullet length.
The solution to increasing the rotational velocity is to either increase the barrel twist or increase the muzzle velocity.
The other causes though may be that the bullet is not sealing the bore properly as it is undersize to the throat and or bore.
I would suggest slugging the throat and bore and comparing that size to the bullet diameter. Ideally the bullet should be 2 thou over the throat size.
If it is not then you will get lots of gas cutting (leading to leading and poor accuracy) and a drop in velocity.
If the bullet is overbore as required then increasing the velocity should work.
Remember the 303 was originally a blackpowder calibre and then transitioned to a 180 grain round nose before coming back to the spitzer we are familiar with.
An original Sparkbrook is probably made for the 180 grain round nose and, if anything like English military guns of the time, may be oversize.
If you truly want reduced velocity then go a lighter (read shorter) bullet that will stabilise at a lower velocity.
Sorry for the spiel. Hope it helps.
One well placed shot is all it takes.