As some of you may remember from my previous posts I am trying to load a .270 win. to specific velocities for some long range shooting from my back porch. I am trying to match the trajectories to the B&C reticule in my Leopold scope.
My two preferred bullet choices were a 140 gr. AB at 2905 fps or a 150 gr. ABLR at 2830 fps. The 150 gr. ABLR was really my first choice but I thought it would be a reach to get a load developed in time and I was working more with 140 gr. AB. The 150 gr. ABLR carried more energy at the longer ranges than the 140 gr. AB.
However, I was getting dismal velocities with the H48313sc powder I was using. When I set the bullet back to match the COAL of the Nosler factory load for the 130 AB I got good groups the velocity was only 2773 fps. Many forum readers suggested that I try some RL22.
I loaded up some:
140 gr. AB with 58.5 gr. H4831sc
140 gr. AB with 59.0 gr. H4831sc
140 gr. AB with 56.5 gr. RL 22
140 gr. AB with 56.5 gr. IMR7828ssc
150 gr. ABLR with 55.5 gr. RL 22
150 gr. ABLR with 56.5 gr. IMR7828ssc
All loads were with new Norma Brass and WLR primers.
All 140 gr.AB's were loaded to a C.O.A.L. length of 3.251". The 150 gr. ABLKR were loaded to a length of 3.380" which is about .060" off the lands.
The results are that the velocity only increased about 10 fps for every extra .5 gr. of of H4831sc. I abandoned that powder.
With the 140 gr AB with the RL 22 gave me an average velocity of 2921 fps with and ES of only 6 fps. The group was 1-1/4" with a vertical orientation. I think the group could be tightened by adjusting the C.O.A.L. I was starting to get get very pleased.
The 140 gr. AB with the IMR7828ssc only gave a velocity of 2830 with a greater variation in both the velocity and the group size. I concluded the that RL 22 woud be the better powder to use wiht the 140 gr AB.
When I shot the 150 gr. ABLR with the RL 22 I was excited to achieve velocities averaging 2844 fps with a ES of only 19 fps. The group was a perfect vertical 1-1/4" group. I was getting excited and figured I was close to finding my load.
Then I shot the 150 gr. ABLR with the IMR 7828ssc. I was astonished to shot a 0.6" horizonal group with an average velocity of 2826 fps with an extreme spread of only 24 fps. I found my load! I am so excited that I can barely type. Of course, I still have to verify the results, try adjusting the C.O.A.L. a little, and sight it in. But, man am I ever happy.
Many thanks to all of the forum users who offered suggestions to my specific case. Also to previous threads where someone suggested the IMR7828ssc with the 150gr. ABLR and where someone suggested trying the ABLR's at .060" off the lands.
If you want pictures, it will have to wait until Monday when I go back to the office. Please advise if you want to see them.
Thanks to everyone!
My two preferred bullet choices were a 140 gr. AB at 2905 fps or a 150 gr. ABLR at 2830 fps. The 150 gr. ABLR was really my first choice but I thought it would be a reach to get a load developed in time and I was working more with 140 gr. AB. The 150 gr. ABLR carried more energy at the longer ranges than the 140 gr. AB.
However, I was getting dismal velocities with the H48313sc powder I was using. When I set the bullet back to match the COAL of the Nosler factory load for the 130 AB I got good groups the velocity was only 2773 fps. Many forum readers suggested that I try some RL22.
I loaded up some:
140 gr. AB with 58.5 gr. H4831sc
140 gr. AB with 59.0 gr. H4831sc
140 gr. AB with 56.5 gr. RL 22
140 gr. AB with 56.5 gr. IMR7828ssc
150 gr. ABLR with 55.5 gr. RL 22
150 gr. ABLR with 56.5 gr. IMR7828ssc
All loads were with new Norma Brass and WLR primers.
All 140 gr.AB's were loaded to a C.O.A.L. length of 3.251". The 150 gr. ABLKR were loaded to a length of 3.380" which is about .060" off the lands.
The results are that the velocity only increased about 10 fps for every extra .5 gr. of of H4831sc. I abandoned that powder.
With the 140 gr AB with the RL 22 gave me an average velocity of 2921 fps with and ES of only 6 fps. The group was 1-1/4" with a vertical orientation. I think the group could be tightened by adjusting the C.O.A.L. I was starting to get get very pleased.
The 140 gr. AB with the IMR7828ssc only gave a velocity of 2830 with a greater variation in both the velocity and the group size. I concluded the that RL 22 woud be the better powder to use wiht the 140 gr AB.
When I shot the 150 gr. ABLR with the RL 22 I was excited to achieve velocities averaging 2844 fps with a ES of only 19 fps. The group was a perfect vertical 1-1/4" group. I was getting excited and figured I was close to finding my load.
Then I shot the 150 gr. ABLR with the IMR 7828ssc. I was astonished to shot a 0.6" horizonal group with an average velocity of 2826 fps with an extreme spread of only 24 fps. I found my load! I am so excited that I can barely type. Of course, I still have to verify the results, try adjusting the C.O.A.L. a little, and sight it in. But, man am I ever happy.
Many thanks to all of the forum users who offered suggestions to my specific case. Also to previous threads where someone suggested the IMR7828ssc with the 150gr. ABLR and where someone suggested trying the ABLR's at .060" off the lands.
If you want pictures, it will have to wait until Monday when I go back to the office. Please advise if you want to see them.
Thanks to everyone!
