I went to the range to put a few rounds through my new to me lee enfield no4 mkII. It is post war produced and almost new in terms of condition, so I'm thinking the rifle is not my issue here.
All I had for ammunition was some handloads made up of new Winchester brass, 42 grains of R15, and 125g Sierra that I had on hand. It is my accuracy load in a different .303 I have.
My accuracy was wierd to say the least. I was getting shots that were vertically accurate but they were stringing into two groups about 5" apart. Also my cases were really black around the neck and I was even getting blowback into the action with a couple rounds. They looked like this;
I do have faith in the gun though, because non of my other firefirmed .303 brass will come close to entering this chamber.
My theory is that the 125 grain bullets were to light to cause any significant pressure, resulting in the brass not expanding enough to fill the chamber. Also because the bullets are so short, I also theorize that the gasses are escaping around the bullet because the ogive would maybe not be in contact with the grooves before the base of the bullet left the case... That is the other thing, the brass is short. I usually trim my brass long, but this batch of Winchester required me to trim to .10" shorter than usual. I only neck sized the new brass before trimming also.
My plan is to try to find some 150-180g bullets and anneal the partially fire formed brass in the hope that I get a good chamber seal and adequate pressure. Also to reduce gas blowing by the bullet.
Does this seem logical? Would anyone else try something different?
All I had for ammunition was some handloads made up of new Winchester brass, 42 grains of R15, and 125g Sierra that I had on hand. It is my accuracy load in a different .303 I have.
My accuracy was wierd to say the least. I was getting shots that were vertically accurate but they were stringing into two groups about 5" apart. Also my cases were really black around the neck and I was even getting blowback into the action with a couple rounds. They looked like this;
I do have faith in the gun though, because non of my other firefirmed .303 brass will come close to entering this chamber.
My theory is that the 125 grain bullets were to light to cause any significant pressure, resulting in the brass not expanding enough to fill the chamber. Also because the bullets are so short, I also theorize that the gasses are escaping around the bullet because the ogive would maybe not be in contact with the grooves before the base of the bullet left the case... That is the other thing, the brass is short. I usually trim my brass long, but this batch of Winchester required me to trim to .10" shorter than usual. I only neck sized the new brass before trimming also.
My plan is to try to find some 150-180g bullets and anneal the partially fire formed brass in the hope that I get a good chamber seal and adequate pressure. Also to reduce gas blowing by the bullet.
Does this seem logical? Would anyone else try something different?
