Thread: 303 group-bad bedding?

Originally Posted by Cordite

If you have a kinetic bullet puller, empty a case for safety and reseat the bullet to its original position, chamber and extract. Pull and reseat to increasing overall cartridge lengths, load and eject, to see how far out the bullet needs to be to engage the rifling lands. Seat your bullets for that gun a bit short of that. @csmiffy, your groups are not circles, they are being whipped up to the left. You likely have a loose screw.. .

@Cordite good advice-I know about the screw loose-what about the rifle lol
All screws good and tight-I do suspect the bedding and from advice given here, the ammo I have isn't to be trusted.
I don't have a bullet puller but that is something I probably should just get. Or I could put my engineer hat on and make something.
I also think that it isn't just the stability of a boat tail/weight distribution, the theory is more to do with the bum of the projectile not being swaged/obturated against the rifling especially on a worn barrel but good advice still the same.
@Marty Henry I do remember it being the primers as the baddies in the mix for being corrosive-not the powder. I think I will do a bedding job on it. I do need the experience on this project, just was trying not to do it twice.
@shooternz no I haven't slugged the barrel. I was hoping that it might shoot okay with factory ammo and I didn't have to reload at all. in that case 312 is about it.