Accuracy Of Powder Bushings On Mec 600 Jr Mark 5

[oldguyguns]

Bought a used Mec 28ga reloader from a nice gentleman at INGO. Set it up and started checking the accuracy of the powder dispensing. Had bushing one size larger than the chart showed for the Alliant 20/28 that I was using(using #16 instead of #15). The reloader continually dispensed less than what was called for(target 13.0 gn). No problem since I just reloaded the hulls with the accurate dispenser I use for pistol ammo. Have others had this problem ?

Note: I out in a new little metal spacer/washer under the rubber grommet.

Thanks for thoughts

 

[Crandall Crank]

I haven't had any powder that much off from a MEC powder bushing. Were the charges being dispensed all they same or did they vary in weight?

 

[singlesix]

If understand the issue: chart states #15 should dispense x, but it dispenses y? If so, not an issue just find the bushing that gives you what you need. I have a 600 jr and 8567, the bushing chart is a starting point, what matters is that the reloader drops the same amount each time.

 

[4651feeder]

MEC bushings are known to drop light when compared to their published chart. As Crandall Crank stated above, your report of over a grain light seems extreme. I've read barometric pressure and relative humidity claims of impact on drop weight...but am not convinced of their magnitude. If you haven't already, try a RED powder baffle which should allow you to loose the annoying brass washer/rubber grommet and possibly bring you more in line with published drop weights.

 

[Clay Pigeon]

MEC bushings are known to drop light when compared to their published chart. As Crandall Crank stated above, your report of over a grain light seems extreme. I've read barometric pressure and relative humidity claims of impact on drop weight...but am not convinced of their magnitude. If you haven't already, try a RED powder baffle which should allow you to loose the annoying brass washer/rubber grommet and possibly bring you more in line with published drop weights.

Yes and no, smokeless powder is not hydroscopic, it doesn't adsorb humidity from the atmosphere. Powder size and density can change over different lots.
Change the bushing to get your desired weight. You also could buy the adjustable charge bar and eliminate bushings all together.

 

[autogun]

The bushings work in single stage reloaders and progressives. They throw different weights depending on which type of machine they are in. As advised, weigh your charge and find a bushing that throws that weight. You can modify the bushing as well if you are real picky. Enjoy

 

[4651feeder]

Yes and no, smokeless powder is not hydroscopic, it doesn't adsorb humidity from the atmosphere. Powder size and density can change over different lots.
Change the bushing to get your desired weight. You also could buy the adjustable charge bar and eliminate bushings all together.

Agreed it's not hydroscopic, yet at the same time have seen statement from some who load commercially that smokeless powder volume to weight ratio can to a lesser degree than black powder be influenced by humidity at time of shell loading. I'm somewhat remiss for not asking the OP how full his powder bottle was with the light charges. UCBs to me are like Harleys and green tractors; if one has an opinion about them, it's often either love or hate and there ain't no love here.

 

[BE Mike]

The bushings work in single stage reloaders and progressives. They throw different weights depending on which type of machine they are in. As advised, weigh your charge and find a bushing that throws that weight. You can modify the bushing as well if you are real picky. Enjoy

I agree. I have found the MEC powder bushing number have little to do with what weight powder charge they throw. It's kind of a pain to have to buy several bushings to find the right one.

 

[4651feeder]

The bushings work in single stage reloaders and progressives. They throw different weights depending on which type of machine they are in. As advised, weigh your charge and find a bushing that throws that weight. You can modify the bushing as well if you are real picky. Enjoy

Why modify when you can build new? This started as a joke between another relative and myself. Over a year later and I believe he's still using a couple custom sized for him.
View attachment 71996 View attachment 71997

 

[oldguyguns]

Thanks for all the good ideas and suggestions--!!!