I run 10 preset Lyman 55s.
I wrote this series of pieces on the 55 a couple of years back.
Best Powder Measure - Test Results
I tried weighing charges with a Harrell, a RCBS BR model, a Hornady BR and a Lyman 55. I test threw individual loads, then groups of 5 throws weighed together, and then groups of ten throws. I repeated this with two of my more commonly used powders, 23.4 of Benchmark and 12.6 of Lil'Gun.
The Harrell's single biggest advantage is you can reset the volume exactly, every time by just counting the clicks. In fact there is an argument that volume is what you should load by and the weight changing due to humidity etc. should be ignored.
The most accurate, in terms of lowest deviation was the Lyman 55, much to my surprise. Set up properly using the 1st and 2nd slide for setting close (2nd and first slide opened together to 3/4 open or less to get to just under desired weight, if you must open more than 75% go to the largest slide) and then the first slide (smallest slide is always used for fine adjust no matter whether using largest or second largest slide to get first/close weight setting) for fine tuning, it would throw the 5 and ten lot groups at exactly 5 and ten times the nominal weight. On individual loads its max deviation was 1/10, being half a tenth over or under, and the SD was less than half that as 80% of throws were spot on.
The Hornady BR was the next closest for overall accuracy but its SD was over double that of the Lyman. Next were the Harrell and then the RCBS. Between the three they were very close in accuracy, with the Harrell winning the nice to use and easy to reset categories.
One thing I clearly learned in this test, with all of the throwers, was that a consistent stroke and operation were keys to consistent charges, as was ensuring the cavity was in the down position until the actual charge stroke was made. This kept the powder from settling in and packing into the cavity if I took longer to do something between charge strokes.
I sold all my other measures and now have a number of Lyman, all set to specific charges and powders, with one spare for adjusting for the loads I don't shoot as much of, like my big game hunting rifles.
The Harrell Culvers are great and smooth powder throwers and the Culver adjustment is very handy but for pure accuracy I will stick to the Lyman. Also, I bought 6 used Lyman's on EBay for less than the cost of one Harrell's.
I now no longer weigh any charges, except the occasional check charge just because it makes me feel better. In the 4 years since I have gone to this system, I have never had a pre-set one move and I don't adjust them for the humidity effect that can change the nominal weight by volume by 1/10 either way on any given day.
ADDITONAL INFORMATION
Lil'Gun is very fine powder, mostly used in pistols and Benchmark is heavier stick type but not as big a stick as 4895 etc. Those are the two powders I used in the test. I have also thrown a lot of Trail Boss with one and they throw it about 90% dead one, but it is a large fluffy flake specifically designed to meter well. All of the powders I have used in the Varget and below size throw in the 80% or better range for right on, and never go out more than 1/2 a tenth over or under.
Even 30301, 4895 and 4831 throws well out of the Lyman but accuracy on the bigger stick powder runs 2/10s over or under with about only about 40 % of throws right on.
I don't load for pistol so I never tried real light loads of fine powder. If the powder is leaking around the brass slides or drum, try taking it apart and making sure it is spotlessly clean inside. I bought one that was very dirty and it would let powder bind against the drum till I pulled it all apart and cleaned the heck out of it. Worked great after the cleaning.
BLC2 POWDER
With BLC2 at 43grains your Lyman should be throwing very close. A couple of things worth trying. Undo the two slide set screws and slide the assemblies out. Clean them and the interior with alcohol or acetone don't get acetone on the plastic powder column. You need something that evaporates completely. Any residue that makes the powder stick anywhere will play Hobbs with your weights. Then wipe the interior with a static sheet from your wife's dryer supply. To test that you have it clean enough put in some clingy powder like Lil'gun, H335 or the like then dump it back into the canister. If any sticks to the working surfaces of the slide it isn't clean enough. (This picky type of cleaning is needed on all throwers; powder sticking to the thrower is probably the leading cause of poor accuracy. Dillon throwers are REALLY affected by this).
Once it is back together, ensure the baffle is in place, if you don't have one from Lyman, use a large size washer from the hardware, though for powders like BLC2 I usually don't worry about having one in place, I just keep the powder about the same height.
I tested one of mine with some BLC2 this morning. With BLC2 you should be able to do 43 grains using just the top two slides. Move the top two open together till you are just over the 42 reference mark on the brass scale. (They don't really reflect grains of weight, just happened to work out his time) Adjust using the second slide, and keeping the top slide closed, till you get to 42.8 or 9. Use the top slide to adjust to dead on 43, or just lock it down at 42.9.
Throw ten consistent throws and dump them back into the reservoir. Now throw and weigh 5 individual charges, recording the readings. If you are getting variation in weights, try weighing the same charge 5 times on your electronic scale and recording them. I have often found electronic scales to read 2 or 3 tenths difference even when reweighing exactly the same charge. It is why I still use a balance bream for setting and checking powder dispensers.
If the electronic scale reads dead on each time you weigh the same charge, you are good to go but the best non-lab grade ones I have ever tried were always out at least 1/10th on each of 5 consecutive weighings of the same weight.
Now throw five throws into the same pan. It should weigh 215 grains. If not, adjust the scale down till it does, (you almost never have to adjust up). Now weigh individual charges. My bet is, if you are using a consistent stroke and not exposing the charge cavity unless it is in mid stroke, you will be well under 1/10th difference with BLC2.
I know this is a bit of fooling around to get the right set up, but once you do you can throw a lot of loads and not have to trickle, which saves a lot of time.
General instructions for adjusting Lyman55s.
When you set your slides, open the top two slides 3/4s of the way and measure the charge weight. If you are close and just under the target grains you are trying to throw then adjust from there. Use the second slide till you get very close, about .1` or .2 under, then use the top slide for the final add adjustment to get right on.
If the top two won't get you up to your target, at max 3/4s open, then engage the bottom slide. Open it till you a just under but very close to target weight, again about .1 or .2 under. Now DO NOT use the second slide at all. Once again use the top slide for that last little bit to get it right on. If you now use a very consistent stroke, never leaving the slide opening exposed to the powder unless you are in mid stroke, then you should get throws that are 80% or better dead on. Best of luck
