Was the P.08 overbuilt???

[G.T.]

Hi to all! There have been a lot of discussion on witness marks and barrel changing proceedure over the length of the forum.... my question is: Was it necessary to thread the barrel in the first place?? Does the receiver have anything to do with strength, or resistance to failure? Most 9mm barrels on modern firearms are free of any type of support... and then look at a 1911 barrel... it looks as if it should fail on the bench! Could have the P.08 barrel been pinned in place, and worked just as well? What do ya think! Till...later....GT <img border="0" alt="[jumper]" title="" src="graemlins/jumper.gif" /> <img border="0" alt="[jumper]" title="" src="graemlins/jumper.gif" />

[Edward Tinker]

GT, I think it was? But back then, many inventors overbuilt on purpose. If I remember correctly, John Browning purposely built them 20% stronger than he thought an owner would reload for. Since this was just after black powder and smokeless were the on-going experiement, inventors were still leery of under-gunning the pistol in strength.

Just my feeling on it,

Ed

[policeluger]

I think a German craftsman would have walked off the job rather then "pin" a barrel in place. The pistol may be over machined by today standards, but isn't that one of the reasone we love them. I have no problems with computer machined and poly/plastic, but I do not believe we can ever replace old world craftmanship. I also do not think "pinning" a barrel was in thier mind set, cheap manufacturing was not the was thier thinking.

[Heinz]

GT, I think threading is mandated by the toggle mechanism. The Colt/Browning drop link uses a different method of locking the breech bolt to the barrel,the reciever is locked to the breech bolt and the barrel moves. The luger locks via the toggle and reciever is screwed to the barrel.

It could have been engineed differently but then it would have been a 29 Swiss or a Laiti (both still with threaded breeches) :-)

heinz

[Dwight Gruber]

One might wonder as well why the barrel and receiver were not manufactured as one piece. This had already been demonstrated as practicable in the much more complex (from a machining standpoint) Mauser C-96. Also, to GT's point, the Broomhandle chamber area apppears to be vey "light".

A trip through the historical literature (Ian Hogg's "German Pistols and Revolvers 1871-1945" and Edward Ezell's "Handguns of the World") draws forth some interesting observations.

In the earliest varieties of developing auto-loading pistols (generally pre-1910), it appears that the predominant method for barrels permanently attached to a fame or barrel extension (receiver) was to screw them in.

Solid-frame revolvers generally use screw-in barrels, and it could be fairly surmised that early auto-loader designs were based on that example. Hugo Borchardt, through his experience at Winchester during their abortive revolver design exploration, would have been exposed to this method of manufacture. By the time of Borchardt's 1893 patent the gun which was to become the Luger pistol was fully committed to the screw-in barrel.

Browning's dropping-barrel link system was patented by 1897, but even his 1900 FN design screwed the barrel into the frame.

I want to say that inserting a barrel in the receiver and pinning it in place might not be sufficiently reliable over time, that maintaining tolerances might be inadequate or they might loosen in use, that materials available at that time might not be up to the task. The design and construction of the rest of the Luger certainly make that thought ridiculous.

And "pinning" certainly doesn't need to mean a brute-force driven fixture. The 9mm Dreyse comes to mind as I type this, whose barrel is connected to the frame by an axle-pin.

For whatever reason (cultural psychology is interesting but ultimately fruitless in determining motivation) the Germans were apparently not interested in making fundmental changes in Luger construction methods, thus the advent of the P-38.

--Dwight

[G.T.]

Hi to all! Thanks Dwight for the info, and thanks to all for the response! I agree that their way of thinking, and degree of craftsmanship, would not have allowed them to do it any other way, ... perhaps as Heinz mentioned, if there was a change to be made, the Swiss would have done it! It's just in this day and age of barrel liners and sleeves, I just don't have a good grasp on what is a correct wall thickness for a minimum barrel dia.?? BTW, the pencil thin .30 1900 barrels look about as light and thin as you could possibly make any center fire pistol barrel! I have just always wondered if the P.08 receiver is figured in for chamber strength or is it all in the barrel entirely?? Thanks to all, till...later...GT

[Dwight Gruber]

Luger barrel steel is relatively softer, more ductile, than the receiver. WAG could be that this makes parts easier to manufacture, and that the strength is in the receiver.

--Dwight

[Dean]

Perhaps having the threaded barrel was a design choice from the outset. The anticipation of having a common receiver with variable length of barrel options.

In any case, I suspect that the barrel alone is designed sufficiently to contain the pressures encountered. The strength of the receiver is accounted as "extra margin of safety" from a design point of view. The reason I say this is by comparison to barrels in other handguns that I own. Specifically, my CZ52 which fires the hot (1600fps) 7.62x25 round has a chamber wall thickness of about .100" thick, the remaining part of the barrel is .08" thick.

[wterrell]

Dwight, you, sir, are a bright fellow!

[John Sabato]

Okay, let me toss my own in this hat...

I have 'smithed' a lot of handguns in my time (56 years as of last Thursday) ...and I believe that they didn't use the C96 one piece barrel/receiver design because they determined that it was too expensive to produce even then...

...and the threaded barrel methodology was the design of the era... and for that matter, remains so even today on MOST firearms except for auto handguns where the metallurgy and computer assisted design and engineering has developed to the point where they can tell just how much pressure and lockup is required for the bullet to make it out of the barrel before disengaging and starting the reload cycle...

You can all rave about your plastic based GLOCKS and other plastic handguns, they are remarkable in some respects, but in reality aren't they just the result of doing it the cheapest way? Otherwise why didn't they make it totally out of metal?

I don't think that pinning the barrel would have given the long life that the threaded barrel has given this design... a pinned barrel works well on the rimfires because of the lack of pressure, but eventually the pin used to hold the barrel on a high-power cartridge would either become brittle from being constantly workhardened or would start elongating the hole or groove through which it passed...

I wish I had the expertise to calculate the G-forces that the whole Luger pistol experiences in the firing cycle, but I don't... but I would wager that the forces that exist between the breechface and the barrel at the time of firing, shove that whole upper assembly back, snap open that toggle and then slam shut on the next round are SUBSTANTIAL... I wouldn't trust a pinned barrel for a hi-powered round like the 9mm P with just any design...

If it were such a good idea, wouldn't Walther have just upped the size a tad on the PP type design and used the 9mm P cartridge to meet wartime production and help standardize the ammo? Why bother with the P-38? My guess would be they tried it and the guns disintegrated...

IMHO The pinned barrel meets its practical limit in the .32 & .380 ACP, or 9mm Makarov rounds... The Astra designed series (400-600) of pistols while serviceable, are CLUBS compared to the precise engineering used in a Luger... over engineered? Naw! Designed to specifications is more like it... and have you ever seen a Luger that didn't shoot well? ...not many.

...but of course I am a wee bit biased...

[lugerholsterrepair]

"You can all rave about your plastic based GLOCKS and other plastic handguns, they are remarkable in some respects, but in reality aren't they just the result of doing it the cheapest way? Otherwise why didn't they make it totally out of metal? "

John, Because of weight.

If you heft a Luger and a Glock side by side it becomes immediately apparent. Now I detest the new plastic pistols from an esthetic point of view but they are a marvel of technology. If one wants to conceal carry there is now a lighter choice. Police agencies are the drivers of this and the DAO concept.

To answere GT's question, the FEG PA-63 is an example of a pinned barrel as is the Makarov.These have been found to be very accurate and reliable. While not the same caliber it seems to work. These are from the German PP and PPK design, aren't these Pinned as well? Jerry Burney

[Barry Briscoe]

The action is locked long enough for the chamber pressure to drop to a safe level before unlocking with the Luger,P38,Colt 45,and P35 versus a straight blowback design like the Walther PP/PPK or Makarov with light slides and recoil springs firing lighter bullets with less chamber pressure.

An exception would be an Astra 400 or 600 which are a straight blowback,but they have a strong recoil spring to deal with the chamber pressure of a 9mm Luger.

Heckler and Koch barrels are installed with a press fit and a pin through the receiver trunnion on their 9mm,10mm,.223,.308 series of firearms SP89,HK94,MP5,MP5K,HK93,HK91,G3,HK21,etc....

AK47's use pinned or threaded barrels also.

There is no reason a pressed and pinned barrel could not be used on a Luger that I can think of other than the shank diameter of the barrel,bore diameter of the barrel extension,and chamber dimensions would have to be made to tighter tolerances to achieve a press fit and proper headspace.

[John Sabato]

Jerry, perhaps if I "carried" for a living instead of on appropriate occasions, I guess weight might matter to me... but what does matter to me is endurance... For years I practiced most with a steel frame gun and for the last magazine or two I would use my M1911A1 that I built on an aluminum frame... a major difference in weight but not function and sight picture...

I doubt many of the 'plastic' framed guns could have taken the pounding I have given that Aluminum frame and still be in service... and my steel frame 1911A1's will be in service long after they pry them outta my cold dead hands...

[unspellable]

A side issue to the pinned barrel question.

If you compare an older S&W revolver with a Colt revolver you will find the barrel on both revolvers is screwed into the frame but the S&W barrel has a pin through the upper part to prevent it from unscrewing. The Colt on the other hand has a "crush" fit. The pin costs a bit more (Hence S&W has dropped it.) but it avoids distorting the rear of the barrel as the crush fit does. Supposedly the pinned barrel will be more accurate all else being equal. Now in comparing the S&W to the Colt this difference is probably lost in the noise, but in this latter time we know how to build a revolver that will produce minute of angle accuracy and such points would matter.

of course, for some obscure reason, it is not S&W or Colt that one goes to for a minute of angle revolver.

[Doubs]

John, I enjoyed your thoughts until you reached the part about the Astra 400/600 series. They do not have the appeal of a Luger but the fit of moving parts is excellent unless you find one that's been worn out. The quality of the machine work is better than most, IMO. I once owned a 600 - purchased new from "Ye Olde Hunter" for $19.95 IIRC - and it had a terrible trigger but was VERY accurate and the fit and finish was exceptional.

[Roadkill]

Once again you are applying modern thinking to late 19th century technology. The year was 1900. Were there any pinned barrels on anything? Labor was very cheap. There is no plastic. Parts are hand fitted to each gun. What other means were availble to attach barrels to guns? What was the current technology on other mass produced firearms
at the time? What had been tested and proven to be absolutely reliable for military use? What metalurgy was available at the time? There had never been a 9mm before, not something to experiment barrel attachments with.

rk

[Dean]

I recall reading somewhere that peak pressure occurs after the bullet has traversed some distance down the barrel. In rifles this was around three inches. This being the case, and the fact that a luger barrel quickly tapers to a thickness that approximates that at it's threaded portion leads me to believe that the barrel alone is designed to contain the pressure of the round.

In any case gun barrels in general are usually "way over" designed. Something like a factor of 4X the required strength.