p" 0.125 inches in depth (radially) I am looking at print 48-02 of the RG G design and I want to make sure of one of the details. This print shows a rear barrel plate which is designed to be used with the drum magazine. In a phone conversation with Paul Moore quite a while ago, I was informed that if I was planning to build using the stick magazine I would not have to do the work involved with the 0.125 dowel pins in the 10 places. There is also a feature which Paul did not mention at that time, which is what looks like a "scallop" (0.125 in depth) between each of the pins. This is shown again on the print in the 4:1 scale enlarged view. Am I correct in assuming that this feature is unnecessary on the stick magazine version?
Rear barrel plate print feature
Posted 23 January 2020 - 12:38 AM
Those "scallops" allow clearance of the pins in the escapement (feed) wheel in Paul Moore's drum magazine. I redrew all of this some years ago and changed the clearance cuts so that they would be cut 90 degrees from how Paul had it, plus gives some more clearance for the pins in the wheel. See attached photos of my barrel plate that is setup for a drum magazine. The other guys are correct that you don't need the pins or scallops if you plan to only use the stick mag.
For anybody else that is reading this and wants to build a drum mag, the RGG plans on the drum magazine seem to need "tweaking", Paul Moore has stated such. Nonetheless, a brass drum magazine is too cool to not try to get working.
I made the pins stick out of the barrel plate a little longer, then had to make a relief cut under the magazine well and in the side frames for some clearance. The pins need to stick up from the barrel plate .130/.135 to work with the .750 BC on the feed wheel pins and prevent binding between pins. The RGG mag also needs "feed" lips to help get the shells into feed wheel and out to drop in the carrier block. I monkeyed around with this a bunch and finally got LR shells to be able to feed through the feed wheel reliably without hanging up. I made a left and right feed lip to work on the rim, then a right center feed lip to prevent any "feed throughs" where the shell didn't drop out of the feed wheel. Working the feed wheel by hand, I don't get any hangups like I did before without the feed lips.
The current RGG drum design requires the shells to move somewhat up into the feed wheel before making it out of the drum magazine, the left feed lip helps to get the shell positioned correctly in the feed wheel, the right feed lips make sure the shell drops.
I have been playing around with a modified design incorporating ideas from Cutter's gear drive drum mag. I think you can still use the pin system, keep the same center-to-center distance between the the center of the rotating barrels and the center of the feed wheel, but instead of having the shells going around at the edge of RGG drum magazine, use a smaller circle of shells that will feed through the center of the feed wheel. A couple of black delrin inserts in RGG drum magazine can make the new path of the shells. Then use a large OD feed feed and could still have the pins on it with the .750 BC (actually I think if it is increased to about .79 BC, it would be better interaction with the the pins sticking out of the barrel plate.
I will see if I can take some screen shots of this idea and post in the next few days, but will start a new thread. RGG Drum Mag Improvements
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