A little farther down the rabbit hole

[scudzuki]

In recent history I bought a new A&D FX-300 magnetic force restoration balance (milligram resolution, which equals .02 grain resolution).
I then found an A&D HR-120 (list approx. $2200) on ebay, minus the weighing pan and power adapter, which was displaying a -E when powered up.
Being as my new A&D balance displays the same error when the pan is missing, I took a chance for $41 shipped.
When it arrived I powered it up with the P/S from my other balance and by adding some weight to the stage (where the pan mounts), I got it to register weight.
I ordered the parts for the pan ($100 shipped) and made up a power supply for it from some old adapter scavenged from who knows where.
In fact, the plug from the adapter matched, as did the voltage; only the polarity was backwards (apparently the Japanese standard is + tip and - ring) so I cut, spliced, soldered, and shrink wrapped the output wire, and voila, a working balance, with a resolution of a tenth milligram or .002 grains.

I did notice that the balance was very sensitive to the weight being centered in the weighing pan, and a call to A&D reveled that my new acquisition was out of spec by a factor of 1000. Hmmm. A&D charges a flat rate of $695 to repair the balance... not gonna happen. Since I had nothing to lose, I took the lid off and studied the stage suspension, and found 2 little brass machine screws, obviously the adjustment for the stage. I turned off the AC in my house and within an hour I had it within .0002 grams from center to edge, or half of spec. Schaweeeet!

Now I'm contemplating chopping grains of AA4350 and I4895 in half because I'm not happy with charges that are .010 light or heavy. I'm not quite there yet, though.

In the meantime, the NECO concentricity gauge I bought LNIB from a Hide member shows up, and once I added an old Starrett "last word" indicator to measure the bullets at 2 locations in one setup, I'm appalled by how far out some of my reloads are,
Some are as bad as .004" TIR runout of the bullet right next to the case neck and .008" TIR at the tip.
Most are much better, .002" next to the neck and .004" at the tip (or less).
Lapua once fired brass, neck sized in a Lee Collet die.
The runout at the neck of the case is practically nil, maybe .0005" (half a thousandth), so the bullet runout must be caused by case wall variation. I guess it's time to turn the necks.
Not bad for an old RCBS press and Lee dies...
There is no curvature ("banana") in the cases, either, measuring .0005" TIR.

Meanwhile I made a rig to straighten the ones I have loaded. Drilled fixture holes with drill bits a few thousandths at the most over the neck diameters (.260 and .308) and rigged up an old Federal tenths (.0001") indicator I've had sitting around for 3 decades. Finally found a use for it, providing some indication of how far I'm "bending" the cartridges.

I have found that I have to "bend" the case .030" (about 1/32") to get the cartridges to even move... that is, I apply some pressure on the side of the case, note the reading on the indicator, and move the rim end of the cartridge 3 revs (.010" per rev) before the cartridge moves enough see any change in the bullet runout.

My goal, of course, is to not have to "fix" bent rounds, but to have my reloads come out of the press relatively straight.
I'm hoping that I can eliminate the stray shots (flyers?) that always mess up my groups when they're shaping up to be "tight".
If eliminating these variables doesn't help, well, I guess it's a little further down the rabbit hole I go.

Fun journey either way.

Joe

 

[former naval person]

When you get to chopping granules, remember that cutting the granules changes the burning rate, so you'll have to run tests to determine if half granules or one-third granules give the most consistency, then get your charge tables refined to reflect whether the cuts are on a bias or straight across. Plus you'll need your millimeter based radar to verify the ES of the changes. Keep up the good work.

 

[scudzuki]

When you get to chopping granules, remember that cutting the granules changes the burning rate, so you'll have to run tests to determine if half granules or one-third granules give the most consistency, then get your charge tables refined to reflect whether the cuts are on a bias or straight across. Plus you'll need your millimeter based radar to verify the ES of the changes. Keep up the good work.

Yeah, well, like I said, I'm not there yet.
I read where some BR shooters are drilling out the cores of their extruded powder granules with different sized drills according to how much has to be removed to make each granule the same weight.
I am sure I will never get THERE.

Joe

 

[Rookie]

I found that bending the runout out of loaded cartridges increased my group sizes considerably. As you suggested, try turning the necks and remeasuring.

 

[scudzuki]

I found that bending the runout out of loaded cartridges increased my group sizes considerably. As you suggested, try turning the necks and remeasuring.

The "corrected" rounds shot fine yesterday. AAC-SD shot sub MOA and .260 turned out some groups in the .5s.

I turned the necks of 50 once fired Lapua .308 cases yesterday.

Using a Starrett uni mike over a 3/16" dowel pins reveals at best I only corrected a few ten thousandths of an inch case wall variation so I decided I was wasting my time.

The fire formed then neck sized (with a Lee Collet die) cases are within a thou and a half TIR of true... I think I need a Coax out at least a better press.

Joe

Sent from my SAMSUNG-SGH-I777 using Tapatalk 2

 

[rduckwor]

In recent history I bought a new A&D FX-300 magnetic force restoration balance (milligram resolution, which equals .02 grain resolution).
I then found an A&D HR-120 (list approx. $2200) on ebay, minus the weighing pan and power adapter, which was displaying a -E when powered up.
Being as my new A&D balance displays the same error when the pan is missing, I took a chance for $41 shipped.
When it arrived I powered it up with the P/S from my other balance and by adding some weight to the stage (where the pan mounts), I got it to register weight.
I ordered the parts for the pan ($100 shipped) and made up a power supply for it from some old adapter scavenged from who knows where.
In fact, the plug from the adapter matched, as did the voltage; only the polarity was backwards (apparently the Japanese standard is + tip and - ring) so I cut, spliced, soldered, and shrink wrapped the output wire, and voila, a working balance, with a resolution of a tenth milligram or .002 grains.

I did notice that the balance was very sensitive to the weight being centered in the weighing pan, and a call to A&D reveled that my new acquisition was out of spec by a factor of 1000. Hmmm. A&D charges a flat rate of $695 to repair the balance... not gonna happen. Since I had nothing to lose, I took the lid off and studied the stage suspension, and found 2 little brass machine screws, obviously the adjustment for the stage. I turned off the AC in my house and within an hour I had it within .0002 grams from center to edge, or half of spec. Schaweeeet!

Now I'm contemplating chopping grains of AA4350 and I4895 in half because I'm not happy with charges that are .010 light or heavy. I'm not quite there yet, though.

In the meantime, the NECO concentricity gauge I bought LNIB from a Hide member shows up, and once I added an old Starrett "last word" indicator to measure the bullets at 2 locations in one setup, I'm appalled by how far out some of my reloads are,
Some are as bad as .004" TIR runout of the bullet right next to the case neck and .008" TIR at the tip.
Most are much better, .002" next to the neck and .004" at the tip (or less).
Lapua once fired brass, neck sized in a Lee Collet die.
The runout at the neck of the case is practically nil, maybe .0005" (half a thousandth), so the bullet runout must be caused by case wall variation. I guess it's time to turn the necks.
Not bad for an old RCBS press and Lee dies...
There is no curvature ("banana") in the cases, either, measuring .0005" TIR.

Meanwhile I made a rig to straighten the ones I have loaded. Drilled fixture holes with drill bits a few thousandths at the most over the neck diameters (.260 and .308) and rigged up an old Federal tenths (.0001") indicator I've had sitting around for 3 decades. Finally found a use for it, providing some indication of how far I'm "bending" the cartridges.

I have found that I have to "bend" the case .030" (about 1/32") to get the cartridges to even move... that is, I apply some pressure on the side of the case, note the reading on the indicator, and move the rim end of the cartridge 3 revs (.010" per rev) before the cartridge moves enough see any change in the bullet runout.

My goal, of course, is to not have to "fix" bent rounds, but to have my reloads come out of the press relatively straight.
I'm hoping that I can eliminate the stray shots (flyers?) that always mess up my groups when they're shaping up to be "tight".
If eliminating these variables doesn't help, well, I guess it's a little further down the rabbit hole I go.

Fun journey either way.

Joe

Dude! You are my hero and the Patron Saint of OCD handloaders everywhere.

 

[former naval person]

FWIW..."The Fouling Shot", the magazine of the Cast Bullet Association had a recent article wherein the author, bemoaning the "flyer" that would come along and ruin a one hole group, tried an experiment over thousands of rounds, "perfect" as he could make them cast lead bullets, v/s factory match bench rest bullets in the same heavy bench rifle. He found that the flyer incidence followed the law of random events, and formed bell shaped curves. The perfect bullets would throw a flyer in a random fashion and (!)so would the perfect factory bench-rest bullets. In fact, in his case the lead bullets slightly beat out the match bullets. He said that those results allowed him to quit seeking perfection in bullets and loads,and concentrate on technique in shooting and reading the wind.