handyrandyrc
02-03-2009, 03:29 PM
Load development day! 30-30 is a new round for me, and this Mossberg 464 is a new rifle, so I have some work to do. However, this kind of work is certainly fun.
It was a gorgeous morning here in Southeast Idaho. The sun was up, temperature a balmy 15 degrees F, 30.52 in. barometric pressure, 62% humidity, elevation 4865 feet. No perceptible wind whatsoever. Today, I placed the targets at 50 yards. Bullet chosen was Ranch Dog's 175 grain 30-30 made of wheel weights, gas-checked, and lightly tumbled, then dip-lubed with Lee Liquid Alox. Final step, the boolit got pushed through a .311" Lee sizing die. I shot 6 fouler rounds: each made up with 30 grains Hodgdon BL-C(2). OAL 2.485". The foulers were to get me on target and make sight adjustments, as I had not yet fired the 464 at 50 yards. I made some windage adjustment to the rear sight, shooting once between each change, until I called things 'set'.
I then cleaned the barrel of any powder/lube fouling, ran a couple of dry patches, and started my testing. I had 7 series of 5 rounds each to test. I also made a fouler round for each series, as I would be cleaning the barrel between series. The fouler round was made up of the 30-grain load. The process would be to shoot the 30-grain fouler round at a control target, then the 5 test load rounds at their own target. About 15-20 seconds time passed between shots. After the series, clean barrel, walk down to check and mark results, lather-rinse-repeat.
25-36 grains of BL-C(2) were tested, in 1 grain increments. That gave me 11 points in my data set to work with. All charges were trickled to weight and were all within 1/10th of a grain. All bullets were weighed after lube and gas check. Each were selected to weigh within 1 grain of each other, I picked 175.x grains. All prepared cases were also weighed to within 1 grain of each other, to try and keep external variables to a minimum. Bullets were seated to 2.485" OAL, the length I found best for this Mossberg (just barely kisses the rifling), and finally crimped with a Lee factory crimp die. Remington 9 1/2 standard large rifle primers were used.
* UPDATED * : 50 yard distance -- NOW WITH 25-36 grains inclusive
25 gr. = 2.2" 3 holes, 5.0" furthest 2 holes
26 gr. = 1.2" 3 holes, 5.5" furthest 2 holes
27 gr. = 3.1" 3 holes, 4.0" furthest 2 holes
28 gr. = 1.8" 3 holes, 3.5" furthest 2 holes
29 gr. = 1.5" 3 holes, 3.0" furthest 2 holes
30 gr. = .96" 3 holes, 4.3" furthest 2 holes
31 gr. = 1.8" 3 holes, 3.0" furthest 2 holes
32 gr. = 2.2" 3 holes, 3.7" furthest 2 holes
33 gr. = 1.2" 3 holes, 4.1" furthest 2 holes
34 gr. = 3.6" 3 holes, 5.8" furthest 2 holes
35 gr. = 2.4" 3 holes, 4.5" furthest 2 holes
36 gr. = 2.8" 3 holes, 5.0" furthest 2 holes
* UPDATE * Looks like as I lowered the charge weight below 30 grains, it got worse again. Groups opened up the lower the charge weight became. Statistically, I don't know about my freak results in a couple of places! There does seem to be a sort of trend here, starting with larger groups at 25 grains. As I moved up the scale, it seemed groups started becoming smaller, until 29-30 grains. As I moved above 30 grains they began to open up again.
As I don't have a bench rest / lead sled for the rifle, perhaps I should throw my freak results out (the ones not matching the trend.) However, if I look at both the 3-group measurement compared to furthest 2 holes measurement, I can see where the most consistent groupings were made.
I think I just need to settle on a load and leave it alone now. :) A 29-30 grain charge of BL(C)-2 powder seems to be a fairly good spot for my rifle.
It was a gorgeous morning here in Southeast Idaho. The sun was up, temperature a balmy 15 degrees F, 30.52 in. barometric pressure, 62% humidity, elevation 4865 feet. No perceptible wind whatsoever. Today, I placed the targets at 50 yards. Bullet chosen was Ranch Dog's 175 grain 30-30 made of wheel weights, gas-checked, and lightly tumbled, then dip-lubed with Lee Liquid Alox. Final step, the boolit got pushed through a .311" Lee sizing die. I shot 6 fouler rounds: each made up with 30 grains Hodgdon BL-C(2). OAL 2.485". The foulers were to get me on target and make sight adjustments, as I had not yet fired the 464 at 50 yards. I made some windage adjustment to the rear sight, shooting once between each change, until I called things 'set'.
I then cleaned the barrel of any powder/lube fouling, ran a couple of dry patches, and started my testing. I had 7 series of 5 rounds each to test. I also made a fouler round for each series, as I would be cleaning the barrel between series. The fouler round was made up of the 30-grain load. The process would be to shoot the 30-grain fouler round at a control target, then the 5 test load rounds at their own target. About 15-20 seconds time passed between shots. After the series, clean barrel, walk down to check and mark results, lather-rinse-repeat.
25-36 grains of BL-C(2) were tested, in 1 grain increments. That gave me 11 points in my data set to work with. All charges were trickled to weight and were all within 1/10th of a grain. All bullets were weighed after lube and gas check. Each were selected to weigh within 1 grain of each other, I picked 175.x grains. All prepared cases were also weighed to within 1 grain of each other, to try and keep external variables to a minimum. Bullets were seated to 2.485" OAL, the length I found best for this Mossberg (just barely kisses the rifling), and finally crimped with a Lee factory crimp die. Remington 9 1/2 standard large rifle primers were used.
* UPDATED * : 50 yard distance -- NOW WITH 25-36 grains inclusive
25 gr. = 2.2" 3 holes, 5.0" furthest 2 holes
26 gr. = 1.2" 3 holes, 5.5" furthest 2 holes
27 gr. = 3.1" 3 holes, 4.0" furthest 2 holes
28 gr. = 1.8" 3 holes, 3.5" furthest 2 holes
29 gr. = 1.5" 3 holes, 3.0" furthest 2 holes
30 gr. = .96" 3 holes, 4.3" furthest 2 holes
31 gr. = 1.8" 3 holes, 3.0" furthest 2 holes
32 gr. = 2.2" 3 holes, 3.7" furthest 2 holes
33 gr. = 1.2" 3 holes, 4.1" furthest 2 holes
34 gr. = 3.6" 3 holes, 5.8" furthest 2 holes
35 gr. = 2.4" 3 holes, 4.5" furthest 2 holes
36 gr. = 2.8" 3 holes, 5.0" furthest 2 holes
* UPDATE * Looks like as I lowered the charge weight below 30 grains, it got worse again. Groups opened up the lower the charge weight became. Statistically, I don't know about my freak results in a couple of places! There does seem to be a sort of trend here, starting with larger groups at 25 grains. As I moved up the scale, it seemed groups started becoming smaller, until 29-30 grains. As I moved above 30 grains they began to open up again.
As I don't have a bench rest / lead sled for the rifle, perhaps I should throw my freak results out (the ones not matching the trend.) However, if I look at both the 3-group measurement compared to furthest 2 holes measurement, I can see where the most consistent groupings were made.
I think I just need to settle on a load and leave it alone now. :) A 29-30 grain charge of BL(C)-2 powder seems to be a fairly good spot for my rifle.