Hello fellow gunners! Thought I would just share a little shooting and load development fun I have had over the last while.
I was shooting my 45-70 T/C Prohunter with the Katadin barrel this last week end.
I was having velocity and grouping issues with every powder I tried. It was getting frustrating! Heavy crimp was tried to improve the burning characteristics (get a better full clean burn) of each powder to no avail.
There was always a significant number of powder grains left in the bore after each round fired. Velocities I wanted was barely being achieved, and accuracy really sucked! I was getting 2-1/2 to 3inch, 5-shot groups at 100.
I could ignore a little unburnt powder, as long as the accuracy was present!
My goal was to develop an accurate hunting load with my 418 Grain Cast Lyman, flat nosed RN. I was hoping to get around the 1350-1450fps range in order to keep the recoil down in my light rifle. This velocity range would be more than sufficient for most hunting here in Alberta.
My powder choices went through the traditional IMR3031,IMR4198, H4198, etc. and eventually "lead" me to try IMR SR4759.
My bullet was Lyman mould/Cast bullet, lube-sized to .459" with Lyman Super Moly.
Bullet alloy was 18lbs. of wheel weight lead + 8 feet of 50/50 lead tin solder. Cast about 10 years ago.
I tried to seat my boolets firmly into the rifling to help get my ignition pressure higher, and hopefully get the powder to burn cleaner and more consistantly.
At this seating depth I could not get a good solid crimp due to the top bearing band being located right at the case crimp line.
Even with IMR SR4759's faster burn rate, it burnt dirty as heck!
After much frustration, I finally decided to try some Dacron between the powder and bullet base. This technique worked wonders in my 308Win, so I figured it should work here.
I also Seated the bullet to the crimp groove again and crimped it heavily as well.
Right from the first shots I could feel and see the difference! I fired the first 5 rounds (24.0 Grains IMR SR4759) and managed to print a 1-3/4" group. With 3 of 5 inside 1-1/4". The bore was as clean as though I patched it!
My Standard deviation was 10.76fps (1330fps velocity). I was very pleased with the improvement.
The load at 25.0 Grains of IMR SR4759 shot into 1-1/2" for 5 rounds, giving me an average velocity of 1388fps, and a standard deviation of 8.83fps! wowzers! I know this is only a 5 shot sampling, but it still started to show a positive trend. The bore once again was clean as a whistle!
My final test load of the day was 26.0 Grains of IMR SR4759, and it gave me a five shot group of 1.25"!
4 of the 5 rounds fired were within 3/4"! Average velocity was 1431fps, Standard Deviation was 3.16fps, Extream spread was 8.11 fps! Bore was clean again.
At 26.0 grains the velocity was around my ideal goal range, and recoil was just on the upper side of comfortable. Perfect!
After confirming the load again, I am very convinced of the merits of Dacron filler on ballistic uniformity!
Printing nice tight groups with a large bore ultralight is a riot!
Here is a picture of the rifle I am working on at this time. It isn't the traditional buffalo style 45-70, but it is a fun compact little package! Hope you like the picture!
I was shooting my 45-70 T/C Prohunter with the Katadin barrel this last week end.
I was having velocity and grouping issues with every powder I tried. It was getting frustrating! Heavy crimp was tried to improve the burning characteristics (get a better full clean burn) of each powder to no avail.
There was always a significant number of powder grains left in the bore after each round fired. Velocities I wanted was barely being achieved, and accuracy really sucked! I was getting 2-1/2 to 3inch, 5-shot groups at 100.
I could ignore a little unburnt powder, as long as the accuracy was present!
My goal was to develop an accurate hunting load with my 418 Grain Cast Lyman, flat nosed RN. I was hoping to get around the 1350-1450fps range in order to keep the recoil down in my light rifle. This velocity range would be more than sufficient for most hunting here in Alberta.
My powder choices went through the traditional IMR3031,IMR4198, H4198, etc. and eventually "lead" me to try IMR SR4759.
My bullet was Lyman mould/Cast bullet, lube-sized to .459" with Lyman Super Moly.
Bullet alloy was 18lbs. of wheel weight lead + 8 feet of 50/50 lead tin solder. Cast about 10 years ago.
I tried to seat my boolets firmly into the rifling to help get my ignition pressure higher, and hopefully get the powder to burn cleaner and more consistantly.
At this seating depth I could not get a good solid crimp due to the top bearing band being located right at the case crimp line.
Even with IMR SR4759's faster burn rate, it burnt dirty as heck!
After much frustration, I finally decided to try some Dacron between the powder and bullet base. This technique worked wonders in my 308Win, so I figured it should work here.
I also Seated the bullet to the crimp groove again and crimped it heavily as well.
Right from the first shots I could feel and see the difference! I fired the first 5 rounds (24.0 Grains IMR SR4759) and managed to print a 1-3/4" group. With 3 of 5 inside 1-1/4". The bore was as clean as though I patched it!
My Standard deviation was 10.76fps (1330fps velocity). I was very pleased with the improvement.
The load at 25.0 Grains of IMR SR4759 shot into 1-1/2" for 5 rounds, giving me an average velocity of 1388fps, and a standard deviation of 8.83fps! wowzers! I know this is only a 5 shot sampling, but it still started to show a positive trend. The bore once again was clean as a whistle!
My final test load of the day was 26.0 Grains of IMR SR4759, and it gave me a five shot group of 1.25"!
4 of the 5 rounds fired were within 3/4"! Average velocity was 1431fps, Standard Deviation was 3.16fps, Extream spread was 8.11 fps! Bore was clean again.
At 26.0 grains the velocity was around my ideal goal range, and recoil was just on the upper side of comfortable. Perfect!
After confirming the load again, I am very convinced of the merits of Dacron filler on ballistic uniformity!
Printing nice tight groups with a large bore ultralight is a riot!
Here is a picture of the rifle I am working on at this time. It isn't the traditional buffalo style 45-70, but it is a fun compact little package! Hope you like the picture!
