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Posted: 6/13/2009 9:14:55 AM EDT
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I've read many of the posts explaining how to make the Dillon Powder Measure more accurate and smoother running. I use ball powders so I haven't had any of the accuracy issues those who use powders like Varget have had, but I'd come to realize that the 'clunk' of the Failsafe System has started to wear on me. While the information about removing items or bending pieces on the powder measure is good, I wanted to give the idea a try without permanently modifying my equipment in the event that I didn't like the results. With that in mind, I studied the operation of the Failsafe System and came up with a simple way to disconnect it without modification. I simply took a machine screw, lockwasher, and nut and locked the system down at the bottom of it's swing. It doesn't interfere with the operation nor bind up the linkage. I must admit that I like the smoother operation much better.  |
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I do not run the link on mine... instead, I went to hardware and bought spring to provide resistance in both direction of bar travel., thus my current measure operates the same as the previous DIILON system of past, minus the link down to the shellplate.
Only draw back,, is you have to be aware of the charge bar operation, though that is part of the press operation, watching for things to happen as they should,, and not happen. |
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I also prefer the older 1 piece bellcrank. I have 1 older and 1 newer powder measure and was thinking of having copies of the older type laser cut. I like the quick-fix, too.
Or maybe I could melt down some of this LC 7.62 brass I keep tripping over and cast some parts... 
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Quoted: I do not run the link on mine... instead, I went to hardware and bought spring to provide resistance in both direction of bar travel., thus my current measure operates the same as the previous DIILON system of past, minus the link down to the shellplate. Only draw back,, is you have to be aware of the charge bar operation, though that is part of the press operation, watching for things to happen as they should,, and not happen. If you check out my picture, you'll see that I too have a spring around the base of the measure, I got it from Dillon as its the old one they use to use on the Powder Measure. |
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Quoted: Is this something new, and what press are you talking about? Actually no, it's old and as every Dillon powder measure is the same regardless of press, it works on all of them. What?? You say! Perhaps an explanation is in order. Years back, the Dillon powder measures didn't have the Failsafe Return mechanism that is standard on all Dillon powder measures now. When used on a manually indexing press like the 550B, it was possible to double charge a case if you got to fiddling with something in one of the stations and didn't pay attention. Dillon decided for safety's sake to add a mechanism that didn't allow the powder measure to refill until the handle cycled all the way down. It was thought that this would protect against double charges. Old bellcrank assy. Note the simple bellcrank and rod:  New Failsafe bellcrank assy. Note the double bellcrank where the rod goes through both and pulls the top crank down with the bottom crank when the shellplate assy is lowered. Until the top bellcrank cycles downward, the powder meaure will remain in it's up position and not refill the metered charge chamber:  While this Failsafe system works well and most are satisfied with it, some people would rather do without the 'clunk' associated with the new system. You see, the upper crank assy contacts the powder measure frame and stops the powder measure from dropping down and refilling until the Failsafe rod pulls the assy down. The rod is actuated when the handle is pulled back up to the rest position. Some think that this 'clunk' leads to viarations in powder charges but most just don't like the 'clunk' and would rather have a smoother operating cycle. I haven't found defeating the failsafe system to result in more accurate ammo, but I do prefer the more smooth operation of the press. However, this smoothness comes with a caution. Because the powder measure returns to it's reload position almost instantly, one must be very careful to avoid a double charge. As I have an auto indexing 650, the chance for a double charge is much less than on, say the manually indexed 550b. That is why I chose to deactivate the failsafe assy and return the powder measure to it's original function cycle. |
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COSteve,
If you don't have the spring like yours, does screwing the 2 bellcranks together make any difference? Also what is the point of having the return rod installed if you have a spring that returns the bellcranks? I guess between the casefeeder, the noise/sounds of the rest of the press in full operation, I don't even pay attention to the clunk, but I definitly know what you are speaking of. Thanks, -Masta |
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Quoted: COSteve, If you don't have the spring like yours, does screwing the 2 bellcranks together make any difference? Yes, powder measur will fall via gravity anyway and the top bellcrank would hit the stop, engaging the failsafe. ( BTW, If you need the spring, Dillon will charge you $1 for each spring with about $4 shipping so I just took one [there's one in your spare parts bag] to the hardware store and matched it to some stock springs which cost me 60¢ ea.) That's what the screw and nut accomplish; they lock the top crank in it's down position while the powder measure is lifted via the case and returns down via gravity. The rod ensures that the powder measure returns to it's complete down position. The spring just helps it along and also provides some resistance for the measure on the way up. Also what is the point of having the return rod installed if you have a spring that returns the bellcranks? Belts and suspenders I guess. I guess between the casefeeder, the noise/sounds of the rest of the press in full operation, I don't even pay attention to the clunk, but I definitely know what you are speaking of. Thanks, -Masta |
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I actually found that a predictable clunk from the failsafe rod and the spring around the charge bar reduced the stdev on my measure when using any type of extruded powder. I run the clamping bolts loose when loading rifle rounds so the measure rocks around quite a bit. Effectively the same as rapping the handle on a regular powder measure.
I measured about a 1000 drops of various powders and calculated the stdev back in the day, I did this after every dillon powder measure mod was tried. I polished the funnel, reamed out the drop tube, measure loose on die, tight on die, etc. The loose powder measure with the spring and failsafe rod gave me the best performance. I found no difference though when loading ball or flake powders, so I clamp the bellcrank similar to COSTeve so its quieter. |
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Quoted:
I've read many of the posts explaining how to make the Dillon Powder Measure more accurate and smoother running. I use ball powders so I haven't had any of the accuracy issues those who use powders like Varget have had, but I'd come to realize that the 'clunk' of the Failsafe System has started to wear on me. While the information about removing items or bending pieces on the powder measure is good, I wanted to give the idea a try without permanently modifying my equipment in the event that I didn't like the results. With that in mind, I studied the operation of the Failsafe System and came up with a simple way to disconnect it without modification. I simply took a machine screw, lockwasher, and nut and locked the system down at the bottom of it's swing. It doesn't interfere with the operation nor bind up the linkage. I must admit that I like the smoother operation much better. I added the bolt to mine using it on my T-7 while waiting for my new RCBS ChargeMaster 1500. Worked OK but not as good as on the Dillon press. |
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Yepper I sure got more consistent powder drops with the manually activated DPM. Kept the hopper 2/3 full or better and I could dump IMR4895 pretty darn close....
This mod is old....Eric W. Dillon PM Mod. |
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Quoted: Yepper I sure got more consistent powder drops with the manually activated DPM. Kept the hopper 2/3 full or better and I could dump IMR4895 pretty darn close.... This mod is old....Eric W. Dillon PM Mod. Yes, I saw that mod and it gave me the idea for mine, however, unlike that mod the one I use is totally reversible with no permanent mods to the powder measure. As for the rod, I've found that it ensures that the pm returns fully to the down position. I tried it without it for a while and noticed that every once in a while the pm didn't go all the way to the bottom. I don't know if it needs to but I added the rod and now it does. |
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