Apparently my Rem 700 Custom in .270 Win. likes the 150 CTBST and RL22 Powder. Below are a couple of targets I shot last weekend and this weekend. The first target illustrates loads from 55 grains to 56.5 grains.
Brass: New Norma
Primer: WLR
Bullet: 150 gr. CTBST
Powder: RL22
OAL: 3.400" ~ .025" bullet jump
I shot this target in a snow shower and was very surprised with a 3/4" group using different powder charges.
I had some difficulty with the chronograph. The velocities seemed low and I requested some QL data for my case capacity and OAL. Dr. Mike provided the data and I loaded up some cartridges with 57.0, 57.5, and 58.0 grains RL22.
The results are on the second target. The last four shots (numbered 3-6), loaded at 58.0 grains produced a group of 0.4". All six shots, with varying charges, produced a group of 0.7".
I am very impressed with the consistency of the combination. However, the velocities that I am measuring are NOT tracking well. I overshot my goal of 2900 fps. I am very concerned that the load at 58.0 grains is producing high pressures since the average velocity for the four loads at 58.0 grains is 2974 fps. For my limited experience, that seems high for a 150 grain bullet. I am not experiencing any high pressure signs. The primers don't look any different than those from Nosler factory ammo.
See the trend graph below. It has a trend line for Nosler data, one for QuickLoad data, and one for my measured data. In my data there was a huge jump in velocities from 57.0 grains to 57.5 grains. I can think of three possible causes:
1. I have some bad data on the lower charge weights. Very plausible.
2. Since there was a temperature different between the two days, there is a different due to temperatures. Seems like too much difference for 10 degrees F.
3. I am seeing pressure/velocity increases due to a short bullet jump. Very plausible.
My plan is to:
1. Reshoot charges at 56.0, 56.5, 57.0 and 57.5 grains using the current OAL setting of 3.40"
2. Shoot the same charges with a greater bullet jump. Say an increase of .020" bullet jump to a OAL of 3.38". This should help illustrate if I am getting pressure/velocity increases to due to a short bullet jump.
Questions:
1. Isn't it unusual to get this type of target consistency with differing charge weights?
2. How much of a bullet jump should I have to not experience unusual pressure increases? Will 0.045" be enough?
3. Am I over thinking this? Should I just load up the balance of my components with this load and zero in the scope?
Brass: New Norma
Primer: WLR
Bullet: 150 gr. CTBST
Powder: RL22
OAL: 3.400" ~ .025" bullet jump
I shot this target in a snow shower and was very surprised with a 3/4" group using different powder charges.
I had some difficulty with the chronograph. The velocities seemed low and I requested some QL data for my case capacity and OAL. Dr. Mike provided the data and I loaded up some cartridges with 57.0, 57.5, and 58.0 grains RL22.
The results are on the second target. The last four shots (numbered 3-6), loaded at 58.0 grains produced a group of 0.4". All six shots, with varying charges, produced a group of 0.7".
I am very impressed with the consistency of the combination. However, the velocities that I am measuring are NOT tracking well. I overshot my goal of 2900 fps. I am very concerned that the load at 58.0 grains is producing high pressures since the average velocity for the four loads at 58.0 grains is 2974 fps. For my limited experience, that seems high for a 150 grain bullet. I am not experiencing any high pressure signs. The primers don't look any different than those from Nosler factory ammo.
See the trend graph below. It has a trend line for Nosler data, one for QuickLoad data, and one for my measured data. In my data there was a huge jump in velocities from 57.0 grains to 57.5 grains. I can think of three possible causes:
1. I have some bad data on the lower charge weights. Very plausible.
2. Since there was a temperature different between the two days, there is a different due to temperatures. Seems like too much difference for 10 degrees F.
3. I am seeing pressure/velocity increases due to a short bullet jump. Very plausible.
My plan is to:
1. Reshoot charges at 56.0, 56.5, 57.0 and 57.5 grains using the current OAL setting of 3.40"
2. Shoot the same charges with a greater bullet jump. Say an increase of .020" bullet jump to a OAL of 3.38". This should help illustrate if I am getting pressure/velocity increases to due to a short bullet jump.
Questions:
1. Isn't it unusual to get this type of target consistency with differing charge weights?
2. How much of a bullet jump should I have to not experience unusual pressure increases? Will 0.045" be enough?
3. Am I over thinking this? Should I just load up the balance of my components with this load and zero in the scope?
