lordpaxman
Member
- Joined
- Jun 4, 2011
- Messages
- 2,434
My first modification was to peruse the blue press pages and add a super 1050 to the cart.... I have friends who swear by them and their ability to meter most powders including Hodgdon Clays and IMR Target very precisely. The CFO nixed that mod.
I'll try to keep this concise, but let me back up a bit. My LNL measure does really good (meaning very precise) with some powders, like Titegroup, AA2, N320 to name a few. It does pretty good with others like WSF, WST, Sport Pistol, 244. However, when I tried Clays, and Target, and Red, with a small charge in the 2.5-5 gr range, I routinely saw +/-.5 gr, and occasionally swings of .8gr. With the faster powders, and small charge weights, that's unacceptable.
The LNL rotor rotates down across the back of the powder hopper, however when I watched the action, I could see two things that could be improved. The first was the curvature of the hopper, and the second was the angle the rotor intersects the powder cut-off point. It appeared powder would be both compressed in the cavity as well as sheared off the top as the rotor rotates downwards.
I wanted to modify this to be more like a baker shaving off the top of a cup of flour with a knife. I added a fillet of epoxy with the rotor in place and just enough so the small cavity in the pistol rotor was completely exposed.
Preliminary testing shows a marked increase in precision. For IMR Target, Avg 3.0gr, +/- .19gr, Clays, Avg 2.1gr, +/- .07gr, and N320, Avg 3.1gr, +/- .06gr. The sample size was 12, it's not statistically significant but the results look encouraging.
I'll add a few more details just in case anyone's interested. I scuffed the back of the powder hopper with 220 sandpaper and cleaned with acetone. I had three coats of Johnson's paste wax on the rotor and rotor housing, and filled the pistol rotor cavity with wax as well. I carefully used a small wooden tool to caulk the rotor/housing seam with wax as well. I did want the rotor to rotate after the epoxy sets up. I had some West Systems 105/206 epoxy with 406 filler and thickened the mix to be quite viscous, about heavy cream to hot peanut butter consistency. The epoxy should be able to flow and fill the circular void in the back of the powder hopper, but not too loose so it runs everywhere.
I didn't check the rifle rotor cavity as this press sees pistol only. Time will tell how this performs but I'm optimistic this will help. It will most likely wear over time so I'll need to keep an eye on it. I also noticed that for the powders I tested, the prior micrometer setting produced about a .5 gr greater throw. That further suggests the powder was being compressed in the cavity somewhat. How much would depend on the specific powder characteristics. It also means all those metering inserts I had calibrated will need to be re-calibrated.
Merry Christmas!
I'll try to keep this concise, but let me back up a bit. My LNL measure does really good (meaning very precise) with some powders, like Titegroup, AA2, N320 to name a few. It does pretty good with others like WSF, WST, Sport Pistol, 244. However, when I tried Clays, and Target, and Red, with a small charge in the 2.5-5 gr range, I routinely saw +/-.5 gr, and occasionally swings of .8gr. With the faster powders, and small charge weights, that's unacceptable.
The LNL rotor rotates down across the back of the powder hopper, however when I watched the action, I could see two things that could be improved. The first was the curvature of the hopper, and the second was the angle the rotor intersects the powder cut-off point. It appeared powder would be both compressed in the cavity as well as sheared off the top as the rotor rotates downwards.
I wanted to modify this to be more like a baker shaving off the top of a cup of flour with a knife. I added a fillet of epoxy with the rotor in place and just enough so the small cavity in the pistol rotor was completely exposed.
Preliminary testing shows a marked increase in precision. For IMR Target, Avg 3.0gr, +/- .19gr, Clays, Avg 2.1gr, +/- .07gr, and N320, Avg 3.1gr, +/- .06gr. The sample size was 12, it's not statistically significant but the results look encouraging.
I'll add a few more details just in case anyone's interested. I scuffed the back of the powder hopper with 220 sandpaper and cleaned with acetone. I had three coats of Johnson's paste wax on the rotor and rotor housing, and filled the pistol rotor cavity with wax as well. I carefully used a small wooden tool to caulk the rotor/housing seam with wax as well. I did want the rotor to rotate after the epoxy sets up. I had some West Systems 105/206 epoxy with 406 filler and thickened the mix to be quite viscous, about heavy cream to hot peanut butter consistency. The epoxy should be able to flow and fill the circular void in the back of the powder hopper, but not too loose so it runs everywhere.
I didn't check the rifle rotor cavity as this press sees pistol only. Time will tell how this performs but I'm optimistic this will help. It will most likely wear over time so I'll need to keep an eye on it. I also noticed that for the powders I tested, the prior micrometer setting produced about a .5 gr greater throw. That further suggests the powder was being compressed in the cavity somewhat. How much would depend on the specific powder characteristics. It also means all those metering inserts I had calibrated will need to be re-calibrated.
Merry Christmas!