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Powder cop review

Discussion in 'Handloading and Reloading' started by sugarmaker, Dec 24, 2011.

  1. sugarmaker

    sugarmaker Well-Known Member

    Thought I'd post the results of my rcbs (mechanical stop) vs dillon (beep) powder cop comparison. Both systems on an LNL-AP.

    >>>Mounting: RCBS wins.

    RCBS is a screw in die. I have it on its own bushing, pretty simple.

    Dillon: Check somewhere, I posted a pic how I got the LNL measure to actuate the dillon case check using the expander stop attachment w/o mods to the press.

    >>>Setup / adjustment: RCBS wins on my press if caliber changes, otherwise Dillon is easiest

    Dillon: The way I actuate the dillon is pretty simple, but the LNL measure is a PIA to get set for flare and rotor travel, and adding and the dillon compounds the complexity. Once set up it work well, 10 mins is about right. The dillon is super easy to adjust once the measure is working, the notched pushrod and beeper actuator are nice.

    RCBS: Fairly easy IF you don't need to change the plunger foot from small to large. The plastic foot pushes onto the plunger so tightly I'm not sure it's ever coming off. Place a properly charged case, adjust until it clicks a little, that's it.

    >>Flexibility: Dillon wins, it'll do smaller calibers

    The RCBS diesn't do anything smaller than 9mm. The dillon does .22 on up.

    >>Accuracy: Dillon by a wide margin

    RCBS has a 3.5 grain window (using bullseye in a .357 mag) between over and under charge, for 100% reliable stops. It complains at about a 3 grain window but won't always catch reliably. I'm throwing 3.5 grains, so I've got high at 4 grains and low at .5 grains.

    Dillon has a 1.8 grain window under the same conditions.

    >>holds adjustment: Jury is out on this one.

    The RCBS has a screw out adjustment that is a bit loose in my opinion AND can't be locked, BUT, several hundered rounds and it hasn't moved

    Dillon has a screw nut, once set it isn't moving

    General notes: These both work well for their intended purpose. If we look at double charges, the 3.5 grain range of the RCBS means it'll catch 1.8 grain nominal settings being double charged to 3.6 grains. The dillon is accurate enough to catch smaller variations in powder charge. When deteting an error, RCBS mimics a misaligned case mouth on the sizer, while the beep of the dillon means only one thing. I have not had a bona-fide charge error yet, but I have had several case mouth hang ups and I'm always paranoid it is a double charge when using the RCBS.
  2. Tom488

    Tom488 Well-Known Member

    For this reason, I adjust my lock-out die to sit a little bit higher - that way, if it locks up on an over/under-charge, the handle is in a different position than it is when a case mouth hangs up on the size die.

    When the handle jams sooner in the stroke, I know to just adjust the case to fit into the size die. If it jams later in the stroke, I know it's the lock-out die causing the stoppage.
  3. dirtengineer

    dirtengineer Well-Known Member

    I have the RCBS lockout that I use on a Hornady LNL. I hear what you are saying with the plastic foot. It would better if it had a screw in foot of some sort.

    I didn't know about the size of the grain tolerance. I figured it would only catch a double charge or no charge condition.
  4. Peter M. Eick

    Peter M. Eick Well-Known Member

    Just buy two of them. I have a small foot one and a large foot lockout die and then switch as needed.

    I find that my tolerance is smaller than yours. I would have said it was +/- about 1 grn on a 38 special.
  5. Striker Fired

    Striker Fired Well-Known Member

    That tolerance seem high and dangerous to me,if a person is at max on a load and it doesn't stop a load that is 1gr or 1.5gr higher, K-boom .:cuss:

    I made my own electronic buzzer check die that will detect down to .1gr with most powders and .2gr-.3gr on the finer ones. To me , preventing any dangerous load should be the job of a lockout/powder cop die, not just double charge or a partial overcharge.
  6. sugarmaker

    sugarmaker Well-Known Member

    Did a tolerance re-test with the smaller loads, 3.5 grs nominal bullseye

    Dillon:low beep 2.7 high beep 4.3, 1.6 gr range
    RCBS:low lock 1.2 high lock 4.1 2.9 gr range

    Either of these measures can be set to reliably lock / beep at .5 gr over or less without false lockup / beep.

    With larger charges (9 grains) the numbers go up to 3.5 / 1.8.

    I also set the lock out to lock higher in the stroke, much easier to tell from a case mouth jam, thanks Tom.
  7. jef2015

    jef2015 Well-Known Member

    I just loaded my first batch with the RCBS lock out die. I use a Dillon 550 and will crimp on a RCBS Rock Chucker. It locks up tight with no charge or double charge. I worry much more about missing a powder drop or double loading than the powder drop accuracy. The powder drop has always been accurate to +/- .1 grain. For someone who has problems loading without distractions (2 year old in the house) I feel much more confident after loading, although it does take a little longer.
  8. Muddydogs

    Muddydogs Well-Known Member

    Has anyone ever had a thrower throw more the 1/2 grain different? In all my years of reloading I have never had the uniflow throw more then + or - .5 grains, I don't really remember anything more the + or - .3 grains and the LnL is doing just as good so it seams that these check dies are way out there for most throwers. A grain or grain and a half over charge is very easy to spot as in rifle there should be powder spilling on the shell plate and pistol would be obvious. When I start a new load sequence I load a case at the charge weight and a couple with heavy charges as well as light charges so I can visually see the difference and get my eye adjusted then I adjust my press light so I can see in the case and I pay attention to the powder charge as I am reloading. Kinda seams like these check dies take up a die hole and are kinda a falls sense of security. With todays progressive presses you have to be trying hard to get a double charge and with any press malfunction a guy should stop reloading and check everything after the malfunction is taken care of before just cranking out more rounds. A missed charge is just a good indicator that you need to stop reloading until you can give it the full attention it deserves.
  9. Tom488

    Tom488 Well-Known Member

    Yes. I disassembled my Uniflow to clean it up, and when I reassembled it, I didn't tighten the micrometer stem into the cylinder all the way.

    I set the measure to through 4.2gr of Bullseye. After 200-250 rounds or so, the repetitive up/down motion of the micrometer stem caused it to back out (remember, it wasn't fully tight), and by the time the lock-out die was starting to click, I was at 6.2gr.

    Granted, this was a pretty unusual circumstance, ultimately caused by operator error. Under normal operation, I agree it's extremely unlikely a case-activated powder measure will over-throw a powder charge. And, at least with pistol powders, very unlikely to under-throw, as well. When dealing with rifle powders, long stick powders at that, the possibility of an under-throw due to powder bridging is very possible.
  10. joed

    joed Well-Known Member

    I had squibs from my Dillon powder measure using Unique, that was over a 5 gr difference. Since then I've quit Unique and moved on to Universal and Power Pistol. I purchased the powder check die after the squibs. Using up the last of the Unique it wasn't unusual for the powder check to beep once in awhile.

    More then anything it's the type of powder used that will cause problems.
  11. Peter M. Eick

    Peter M. Eick Well-Known Member


    Call RCBS. Your range is too high. I suspect you have something wrong with your lockout die. Maybe it was fiddled with during shipping or something. Both of mine is much tighter response than yours.
  12. Striker Fired

    Striker Fired Well-Known Member

    For me a powder check/cop is for a backup insurance,not to be relied on so you don't have to watch what your doing.Things happen,phone rings,someone knocks on the door,you drop something off the table,any little thing that maybe distracts you that one time and you don't move the handle right,whatever.I would say that very few people can HONESTLY say they have looked into every single case that they have ever loaded,no matter what.
    That is why I like to use a check die as long as I have the room.

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