Drum beat
 

Hi to all, well the relentless repair of Luger drum magazines continues, and I am reminded of the star wars line, "don't get cocky kid!" as I am constantly learning about new and unusual issues concerning function of these monster drums! ....:eek:... Todays lesson was an easy one in retrospect, but a seemingly impossible task in reality?
It all starts with two mid to late war original BING drums on my workbench. One is a rusted mess, missing parts, and the other is a less rusted mess, just not put together correctly...
So, lets start with the rusted mess missing parts... easy fix, disassembled the drum, cleaned up all the rust and corrosion, reassembled using NUMRICH reproduction parts (most are exact replacements and work great for repairs!) load up 32 rounds, run thru the bench test twice... winner! The world is correctly spinning on its axis!:thumbup:
OK, on to drum number two, less corrosion, all serviceable parts, just clean lube and test right? Not so fast, in the bench test, loaded fine, but when tested for function jammed on the first and second round immeadiatly!!!! Ok, take apart, clean, polish, lube, same result! Again, clean lube, test, no good! Again, again, again... Auurrrgggghhh! what the hell is going on... am I suddenly struck with stupidity? Or, should I slow down, rethink the issue and start measuring some parts? Well, it turns out, measuring the internal dimension of the mag tube was the key to success.. it measured at .395" and it has to be a minimum of .400" so I made a full length .420" plastic insert and drove it up from the bottom and removed. The spring back saw my final dimension at approx. ,405" and guess what, the drum worked perfectly... First time for that, but I'm sure wont be the last... I'll just be a little quicker to the solution than 4 hours of failed testing... ;):cheers: til....lat'r....GT

Gerald, This sounds like my fault...Does the loader look original? Doug told me he was having trouble inserting one of those drums in his carbine? Would expanding the mag affect that?

Hi Jer!
 

Hi Jer, the mag insertion issue was caused by a small but very pronounced outwards dent, dimple, in the mag tube, stopping the mag at about an inch from going in? Very easy to repair, no problem. I can't see where anyone could have done anything to the mag that it wasn't made with? I think it was probably made on the close tolerance side, and perhaps got a slight crush some where in the last 100 years? Nope nothing that was your fault. It was an invisible issue? Needed to be measured to be discovered.. They both work perfectly now... It is a fortunate occurrence that the NUMRICH manufactured drums are so close of a copy we can swap parts and repair original serial numbered drums!
Best to you Jer, til.....lat'r.....GT....:cheers:
BTW, loader looks 100% original & correct to me? Fits both drums perfectly... best, GT

You are the man Gerald. Thanks for all you do for this hobby. John