Wednesday, June 25, 2014

A mod for the Lee Perfect Powder Measure

When it's connected to the Universal Powder Charging Die

While back I bought one of the measures, and it's worked well.  I dug around and found that the Universal Die would let you mount it on a progressive press, my Dillon 450 in this case(Yes, it came with a measure.  Like most, it doesn't play well with stick powders like IMR4895 or H4198, whereas the Lee works quite well.  Thus the change)

The UPCD comes with hardware not only to mount the measure, but to hook it up so it will operate automatically.
Nice, but I just wanted it to sit up there and I'd operate the lever manually.
(yes I forgot to put the die body in the picture, I'll try to add it later)

Mounts on the press no problem, but ran into two things:
The tube that you put in the measure was too long to operate the way I wanted, and
the adapters for different length cases all have a concave shape on the bottom where the case meets them.  Probably works fine with the auto-operate setup, but as I used them they wound up leaking some powder granules at times.

Little further explanation:
For auto-charging, you set up the die height and suitable adapter(s) so that when you lower the press handle and raise the case, the case contacts the adapter bottom and pushes the measure up(thus the long drop tube), causing the chain provided to pull the lever down, dumping the charge.  When you raise the handle, the case comes down and a arm pushes the measure lever up, preparing the next charge.

I'd imagine it works fine, with the case mouth actually forced into the adapter, but doing it my way the case would stop at or just before contact, and I'd get the leakage problem.  It's so damn close I can't see how, but it happens.

To work it manually, I needed a shorter tube, and an adapter with a convex bottom.   

The tube, no big problem.  Found a piece of brass tubing a shade oversize in diameter at Ace Hardware, turned a couple of inches down far enough(fine file and then sandpaper while it spun, didn't take much) to fit into the measure.
That's it mounted

The adapter, however, couldn't do that.  Needed a piece of brass a little over the needed diameter(.554" by my caliper) and long enough that I could chuck it into the lathe to shape a piece about an inch long*.  And amazingly, in all the crap in the garage, I had a piece.

No, I have no pictures of the turning; with hands that dirty I wasn't touching the camera.

I cut one end square, then turned 1" of it to just above the needed diameter, then used a fine file and paper to finish it.  The fun part was cutting the concave cone into one end**, but got it done.  Then, since I don't have a drill chuck to fit in the tailstock, took the piece to the drill press and drilled a 1/4" hole just over an inch deep.  Back to the lathe.  Cut off that piece, then chucked it and used a file and paper to shape a nice cone on the bottom end.  Then, just to clean it all up, turned that around and used paper to polish the other end as well.  Didn't do that before drilling because, well, I didn't think to.  Anyway.

Here's the finished piece, top

 and bottom

Drops into the die body, then you screw on the cap, and the tube goes in through the hole. 

Adjust the die so that when the case is all the way up the adapter doesn't quite contact the mouth of the tube.  With the funnel end at the top(just like the original) the powder drops right through, and with the convex funnel at the bottom it's actually inside the case mouth.  I put it all together and loaded about 30 rounds and it worked as should.

And yes, that's a turn of electrical tape around the top of the die/bottom of the measure; just to keep it from turning while I work the lever.  I need to find a better solution for that.

*You've got a lot of adjustment space with the die body, so anywhere from 1/2 to 1" will work; I made mine 1" on the basis that I could always shorten it if needed.

**If I actually knew what I was doing with a lathe, would probably have gone a lot faster.  I need to break down and find a machining class at one of the vo-techs in town.

I did the cutting-off in the lathe: get it spinning, then use a hacksaw.  Gives a clean cut and a square end.


blindshooter said...

One of my press setups is a Hornady Projector with a RCBS measure adapter with a Harrell's measure. Like you I just stop the ram at the top then actuate the measure. Works great for the match rifle loads.

Firehand said...

I hadn't heard of Harrell's before. Which one do you use?

blindshooter said...

Can't remember the model, they don't make it any longer. The new ones have needle bearings I think. They used to have one for pistol and a couple sized for rifle charges. Its very consistent even with stick powder. IIRC it came from Bruno's shooting supply.