OT - metalworking and reloading

We need to discriminate against grinders, cleaning with compressed air, and tools that make sawdust. Keep them at the other end of the shop or outside.

I'm playing with a scheme to automate powder measuring. I found some linear photo arrays (row of 64 or 128 pixels) at Mouser for about 8 bux. I'd use one of those to sense the position of the damping tab (and hence the beam) on the balance. Use that in a simple feedback system driving a small motor that drives a powder trickler. Set balance for desired weight, dump in a scoop of powder somewhat less than desired load, let the system do the fussy futzy job of trickling to desired weight (beam balanced) to within +/- 0.1 grain or less while I'm seating a bullet in the last case filled.

At 600 RPM (small stepper motor), my RCBS trickler delivers about 1.3 grains per second of H380 at full speed, down to about one granule per step at greatly reduced speed.

Not quite as slick as the RCBS chargemaster system, but a hell of a lot cheaper and I already have the balance.

I think volumetric powder measures are fine for handgun ammo, but I like rifle ammo to be loaded precisely. It does seem to make a difference in accuracy.

That sounds like a neat project. Please post a followup on that when you get it working.

Wes

I find that being uniform in speed/tap at end of throw with my RCBS volume measure throws charges well within a tenth-grain . Toss the first five , the powder is still settling . Check every fifth round for the first twenty , then every ten or fifteen . Your requirements may be more stringent , but my light barrel .243 bolt action shoots under a moa with the right load .

Try some 4831...see what the throw to throw variations are....

Gunner

Political Correctness is a doctrine fostered by a delusional, illogical liberal minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

I wonder if Snag meant H4350. I don't see an H450 in the book. 45 gn. of H4350 seems about right for that bullet. Snag, not that it matters since it shoots well for you, but have you chrono'd that load? I'm curious. Quickload predicts m.v. of 3285 fps but I don't know how accurate it is with that powder. I don't trust QL until I've verified with chrono. It's quite good with some powders, not so good with others.

H4350 is also an extruded powder, though not as chunky as 4831. I use IMR4350 for .243, which I think is quite similar to H4350. I get better than 0.5 moa with a 70 gn Nosler BT from a light Savage model

In any case, I just want to see if I could make such a scheme work. The notion of automatically using a beam balance appeals to me. I guess some of the electronic scales, particularly those from RCBS, are pretty good -- but a beam balance made by OHaus and sold by Dillon, RCBS and maybe others, is about as reliable as gravity if kept clean.

My projects don't have to make any sense for me to enjoy them. I have a few scrounge stepper motors anway, thought it'd be fun to use one for something.

I tried "driving" the stepper-motor-powered trickler by hand today, eyeball on the balance and hand on the freq knob of a function generator. MMMMMMMMMMEEEYOWWWW... RRRRR...PT...PT...PT. The balance stopped right on the money, dead bingo. This dog may hunt. Sensors on order from Mouser, I'll start writing code for the $2 microcontroller chip tomorrow. No, wait, maybe Wednesday... Writing code you say? Yes, this is me writing assembly code. Even dinosaurs can learn new tricks. (Spehro, be still.)

BTW, Gunner, 4831SC (short cut) is said to meter better while otherwise working the same. I dunno, that's what it sez in the book. Maybe you've tried both and have found otherwise.

H450 was discontinued some years ago. It was a ball powder. I just checked..Ive still got half a pound on the shelf. 7 Maggy.

Not shabby in the 300 Win and the 375 H&H, though Ive gone to Reloader

From a Hodgen link...in order of burning rate, faster to slower.

H414

Another of the spherical powders, this propellant is useful in medium to large calibers; particularly with lighter bullets.

H450

A spherical powder used for medium and large calibers, it is well suited for maximum loads.

H4831

One of the most popular of all propellants, the manufacturer states that one may use the same loading data as listed for the original 4831 surplus powder. This is an excellent powder for the larger calibers including the magnums.

H870

Slowest burning of the Hodgdon powders, this spherical propellant is only useful in the large, magnum rifle cartridges with heavy bullets."

I was not aware of 4831SC. I imagine it meters a hell of a lot better than the old standard. Of which I still have most of a 8lb keg. My favorite powder for heavy bullets in the 06 and the 35 Whelen etc.

Works pretty well with heavy cast bullets too..but you can dump unburned grains out the muzzle after each shot unless you crimp the shit out of them. Not something I do with cast loads except in revolvers.

"NDTerminator, you might take a look at H4831SC which is the H4831 but in short cut form . It is suppose to meter very well and is close to the H450 performance. I've never tried it myself so I can't give you personal experience. Since Hodgdon doesn't make their own powders they are dependent on other manufactures. Winchester was the maker of the H450 which was identical to Winchesters 785 so when Olin stopped producing the 785, Hodgdon was forced to drop the H450. According to Hodgdon the grains of the H4350 have also been shortened for better metering but they don't list it as a short cut powder." Political Correctness is a doctrine fostered by a delusional, illogical liberal minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

I prefer the H4831SC version. SC = short cut. IIRC 4831 is a bit 'crunchy' going through the measure.

Wes

I use H4831sc in the 7mmMag and it meters through an RCBS uniflow powder measure.

Blue Dot goes a long way at 15 gr in a .223. H4831sc disappears fast at 65 gr in a 7mmMag.