Wolf357

For years I have used an RCBS Uniflow powder measure for both handgun and rifle loads. And I always took the time to weigh every charge thrown for both safety and consistency considerations. But I use far more handgun rounds than rifle, and it gets a bit tedious weighing all those relatively small charges of pistol powder that meter more accurately than extruded rifle powder anyway. So, last year I purchased an RCBS Little Dandy powder measure to supplement my Uniflow, which I now reserve solely for rifle loads. And I soon discovered my new time saver is aptly named, because it has proven to be a Little Dandy.

However, I still weigh the first and every 25th charge of pistol powder thrown by my Little Dandy, which, depending on the powder used, of course, throws various rotor charges very accurately. But, even though a rotor is supposed to throw a specific charge of a particular powder doesn't mean it will. I ordered three rotors for my L.D.; a #7, #8, and #9. Only the #8 threw a specified charge of 6.9 grains of HS6 accurately. The #7 throws 6.2 grains of HS6 consistently when it should throw 6.1 grains. The #9 threw 5.9 grains of PP when it should have thrown 6.2 grains.

This is when I decided to modify the charge hole in the #9 rotor by locking it into a drill press vice, and with an appropriate sized bit locked in the chuck of my drill press, I meticulously altered the depth of the charge hole until the rotor consistently threw the specified 6.2 grains of PP on my 505 beam scale. Later on, I again altered the #9 charge hole to throw 6.5 grains of PP.

As long as common sense, and an accurate reloading scale is used, this modification procedure is safe to perform, and the results will be entirely satisfying. Just remember that when a rotor is altered to throw a charge of one particular powder other than what it is specified to throw, this will also alter the specific charge of every other powder it is listed to throw.

Some will caution that humidity might influence how powder charges are thrown, but I've never encountered this kind of variation. And if an accurate scale is used to monitor thrown charges, this should be of little concern unless someone is storing their canister powder in a greenhouse.

__________________
A modern firearm is just an inanimate tool that is incapable of discharging until a human finger pulls the trigger.

Tubby45

Powder density varies lot to lot so you might find your numbers are different the next lot of powder you buy.

P95Carry

Having used Lee for years - started off for budget reasons but stuck with it .... I use their ''auto-disk powder measuring system in my turrets.

Most times one of the std disks and one of its holes is almost what is needed after test runs but I have sometimes made a small change using a reamer - enough to maybe add half a grain on larger on a specific hole - then marking it. Main thing is staying dead smooth so powder flow not hindered.

True tho powder vols can be slightly batch to batch so - worth trial runs any time. No reason tho not to make small changes if testing is rigorous.

__________________
Chris - P95
NRA Certified Instructor & NRA Life Member.

"To own a gun and assume that you are armed
is like owning a piano and assuming that you are a musician!."

If a BG dies as the result of pointing a gun at me, then he has merely succumbed to an occupational hazard of being a thug

Wolf357

I've loaded several thousand rounds of ammo using my LD, and I haven't yet. But if I should encounter a density variation, there are ways to compensate for it. And since I weigh every 25th charge, no amount of deviation will ever pose a safety hazard for me.

__________________
A modern firearm is just an inanimate tool that is incapable of discharging until a human finger pulls the trigger.

Tubby45

There is always lot to lot variation.

I set the PM to throw a charge and weigh 5 drops before I start the session. If they are within .1gr of the nominal, I roll.

Wolf357

.1 grain variation is something I don't like, but I can live with when it occasionally happens. I thought you initially meant a dramatic variation that definitely posed a safety hazard.

The only handgun powder I've ever encountered that has never thrown charges consistently in either my baffled Uniflow, or my LD is Unique, which is a versatile powder, but I no longer use it for this reason.

__________________
A modern firearm is just an inanimate tool that is incapable of discharging until a human finger pulls the trigger.

Tubby45

I've only loaded a few rounds of Unique for the 357 Mag. I have to get my throats opened up as they are too tight for lead.

I've only used a Lee auto disk pro and the Dillon PM for pistol charges. Never used a Uniflow or similar. Too slow. I shoot way too much to dump each charge like that.

You want to talk about a powder that won't meter? 800X. Meters like crap.

Wolf357

Thanks for letting me know this.

__________________
A modern firearm is just an inanimate tool that is incapable of discharging until a human finger pulls the trigger.

Tubby45

Works great in 10mm for nuclear loads but the metering quality keeps me away from it. You can get similar performance with AA#9 but the charges are large (upwards of 14-16gr) so it isn't economical. I'd put up with it for its excellent metering qualities. I only load nuclear for hunting so a keg would last a long time.