Thread: 303 Query

Originally Posted by rambo-6mmrem

Only problem with that idea is when you neck size a case
And need to full length size occasionally
Every time you full length size that ammo is different to the neck size and will shoot Differently
The best way is to anneal every shot and full length size that way your case is exactly the same every time not Different every so often because you had to size your brass

Not sure it will make enough difference to worry about in a shitty old 303 though
But having said that I wouldn’t trust a 303 chamber to be perfectly round ether which is required for neck size to work Reliably
So in an old rifle like that a full length size is the way to go

In a modern rifle a Partial full length size (Shoulder bump) is the way to go
90% of the world’s top shooters have gone away from neck size in favour of shoulder bump
Due to the above Reliability and consistency issues with neck sizeing

This avo loading 40gr 4064 with 180gr Sierra. All brass annealed. They are chambering unloaded so hopefully it goes well.