Drum beat! lessons learned!

G.T. · 06-12-2020, 07:07 PM

Hi to all! We'll the drum revision project continues to slog along with me trying to find alternate methods of surface prep in order to rein in some of the hours of labor involved? Every once and awhile, I learn something new, and if I don't write it down, I forget it soon after discovery....

... so here is the latest little discovery for your enjoyment!
First I must explain, that the drum / Luger combination requires that both units are up to tip top performance condition, and so it is with my testing Luger for cycling the drum thru its 32 round final bench test. So, say I test each drum twice, that's 64 and lets say ten drums being tested, that's 640 rounds cycled thru my test pistol. now lets take that out to 200 drums... That 12,800 cycles.... not one bang, all done with dummies and by hand...
So, even when I have revised the drum to perform 100%, I still might have malfunctions with the Luger being at fault... along the way, you become acutely aware of what part might be failing, and what to look for, or so I thought until my latest experience...
When cycling the Luger with the drum, I look for positive extraction, and positive ejection, the philosophy being you can't get a new round in, until you get the old one out? So, when I start getting rounds just dribbling out, I look first to the extractor and spring, usually a new spring and a swapped out extractor cure it up... Or, in my case, I replaced the ejector as it had actually hammered it's self loose and a new tight one seemed the way to go? But, still the problem stubbornly refused to be corrected, so I though all that's left was the breechblock, and having some brand new VOPO breechblocks on hand I put one in and tried to cycle the round thru... What I got was a surprise! The round was ejected so positively and violently it caught me completely off guard, missed my brass catcher, and narrowly missed my home computer screen on the other side of the room!!!!

... Holly crap Batman!! Guess what, breechblock condition, or maybe face condition has A LOT to do with positive and hearty ejection!! Annnnd, so endith the lesson for today!

.... best to all, til...lat'r....GT

Karl · 06-13-2020, 11:07 AM

G.T.

Thanks for sharing your experience but can you clarify what was wrong with the original breechblock? One would not expect this part to wear out.

KFS

G.T. · 06-13-2020, 02:30 PM

Hi Karl, the problem breechblock, shows considerable wear at the bottom of the lip on the breechblock face? where it picks up the next round when loading. Nothing that would alarm one to a problem, just no sharp edges anymore? It was a used breechblock when I first installed it, and I don't know the amount of wear or damage that was present initially? And, I was blissfully unaware of any difference that mattered? But, the extraction and ejection was fair, or normal when I started the testing cycle, and degenerated from there. I must say though, I have never, to my recollection, had a Luger work like it does now? I'm not really sure what enabled the now powerful ejection cycle... The issue may be more prevalent in shooters that some one might have polished the breech face to facilitate loading or modified it to solve an unrelated issue? If I learn more, I will report, best to you, til...lat'r.....GT

I dug out the old B'Block and the edge inside the front breech face is still pretty sharp? It leads me to believe the "cure" part of the new B'Block might not be in the front part???... I will look deeper as time permits...

G.T. · 06-14-2020, 12:12 PM

Last night, I drug out the digital calipers and measured the old and worn, versus the new and un-used, and here is what I found. The front edge of the worn breechblock had worn away exactly .005" on the bottom front edge, just from rounds sliding up the breech block face from the magazine... So, if you are going to shoot your Luger, a lot, lot! (waaaay more than a little lot!) Sooner or later you're going to have to contend with the weak ejection as a result of this wear... Everything else measured exactly the same.. I'm not sure, but perhaps WW1 B'Blocks are not as hard as WW2 B'Blocks! I dunno? Best to all, til....lat'r.....GT

Vlim · 06-14-2020, 12:50 PM

I would expect WW1 era breech blocks to be softer or at least less consistent than WW2 era ones. Steel quality, hardening techniques all improved from the 1930s onwards.

I wonder if a regular diet of steel cased ammo would increase wear?

Ron Wood · 06-14-2020, 01:20 PM

A tiny detail that may or may not affect ejection...is there any difference in the depth of the slot in the breech block that the ejector rides in between the old one and the VOPO?
Ron

G.T. · 06-14-2020, 06:27 PM

Hi Ron, Vlim, and all! The slot was about .020" deeper on the problem block? Not sure what to think about that... best, til...lat'r....GT

06-12-2020, 07:07 PM	#1
G.T. Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: Chandler Arizona Posts: 3,507 Thanks: 1,318 Thanked 3,653 Times in 1,004 Posts	Drum beat! lessons learned! Hi to all! We'll the drum revision project continues to slog along with me trying to find alternate methods of surface prep in order to rein in some of the hours of labor involved? Every once and awhile, I learn something new, and if I don't write it down, I forget it soon after discovery....... so here is the latest little discovery for your enjoyment! First I must explain, that the drum / Luger combination requires that both units are up to tip top performance condition, and so it is with my testing Luger for cycling the drum thru its 32 round final bench test. So, say I test each drum twice, that's 64 and lets say ten drums being tested, that's 640 rounds cycled thru my test pistol. now lets take that out to 200 drums... That 12,800 cycles.... not one bang, all done with dummies and by hand... So, even when I have revised the drum to perform 100%, I still might have malfunctions with the Luger being at fault... along the way, you become acutely aware of what part might be failing, and what to look for, or so I thought until my latest experience... When cycling the Luger with the drum, I look for positive extraction, and positive ejection, the philosophy being you can't get a new round in, until you get the old one out? So, when I start getting rounds just dribbling out, I look first to the extractor and spring, usually a new spring and a swapped out extractor cure it up... Or, in my case, I replaced the ejector as it had actually hammered it's self loose and a new tight one seemed the way to go? But, still the problem stubbornly refused to be corrected, so I though all that's left was the breechblock, and having some brand new VOPO breechblocks on hand I put one in and tried to cycle the round thru... What I got was a surprise! The round was ejected so positively and violently it caught me completely off guard, missed my brass catcher, and narrowly missed my home computer screen on the other side of the room!!!! ... Holly crap Batman!! Guess what, breechblock condition, or maybe face condition has A LOT to do with positive and hearty ejection!! Annnnd, so endith the lesson for today! .... best to all, til...lat'r....GT

06-13-2020, 02:30 PM	#3
G.T. Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: Chandler Arizona Posts: 3,507 Thanks: 1,318 Thanked 3,653 Times in 1,004 Posts	breechblock Hi Karl, the problem breechblock, shows considerable wear at the bottom of the lip on the breechblock face? where it picks up the next round when loading. Nothing that would alarm one to a problem, just no sharp edges anymore? It was a used breechblock when I first installed it, and I don't know the amount of wear or damage that was present initially? And, I was blissfully unaware of any difference that mattered? But, the extraction and ejection was fair, or normal when I started the testing cycle, and degenerated from there. I must say though, I have never, to my recollection, had a Luger work like it does now? I'm not really sure what enabled the now powerful ejection cycle... The issue may be more prevalent in shooters that some one might have polished the breech face to facilitate loading or modified it to solve an unrelated issue? If I learn more, I will report, best to you, til...lat'r.....GT I dug out the old B'Block and the edge inside the front breech face is still pretty sharp? It leads me to believe the "cure" part of the new B'Block might not be in the front part???... I will look deeper as time permits...

06-14-2020, 12:12 PM	#4
G.T. Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: Chandler Arizona Posts: 3,507 Thanks: 1,318 Thanked 3,653 Times in 1,004 Posts	Measured and discovered! Last night, I drug out the digital calipers and measured the old and worn, versus the new and un-used, and here is what I found. The front edge of the worn breechblock had worn away exactly .005" on the bottom front edge, just from rounds sliding up the breech block face from the magazine... So, if you are going to shoot your Luger, a lot, lot! (waaaay more than a little lot!) Sooner or later you're going to have to contend with the weak ejection as a result of this wear... Everything else measured exactly the same.. I'm not sure, but perhaps WW1 B'Blocks are not as hard as WW2 B'Blocks! I dunno? Best to all, til....lat'r.....GT

06-14-2020, 01:20 PM	#6
Ron Wood Moderator 2010 LugerForum Patron Join Date: Jun 2002 Location: Santa Teresa New Mexico just outside of the West Texas town of El Paso Posts: 7,022 Thanks: 1,090 Thanked 5,179 Times in 1,703 Posts	A tiny detail that may or may not affect ejection...is there any difference in the depth of the slot in the breech block that the ejector rides in between the old one and the VOPO? Ron __________________ If it's made after 1918...it's a reproduction

06-14-2020, 06:27 PM	#7
G.T. Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: Chandler Arizona Posts: 3,507 Thanks: 1,318 Thanked 3,653 Times in 1,004 Posts	slot depth... Hi Ron, Vlim, and all! The slot was about .020" deeper on the problem block? Not sure what to think about that... best, til...lat'r....GT

06-13-2020, 11:07 AM	#2
Karl Lifer - Twice Over Lifetime Forum Patron Join Date: Jun 2002 Location: Savannah Posts: 522 Thanks: 0 Thanked 271 Times in 118 Posts	G.T. Thanks for sharing your experience but can you clarify what was wrong with the original breechblock? One would not expect this part to wear out. KFS

06-14-2020, 12:50 PM	#5
Vlim Moderator Lifetime LugerForum Patron Join Date: Oct 2002 Location: Europe Posts: 5,053 Thanks: 1,036 Thanked 3,989 Times in 1,205 Posts	I would expect WW1 era breech blocks to be softer or at least less consistent than WW2 era ones. Steel quality, hardening techniques all improved from the 1930s onwards. I wonder if a regular diet of steel cased ammo would increase wear?