Question for the Engineers!!! Luger receivers!!!

[G.T.]

Hi Guys! I've thought a lot about the different materials that could be utilized for luger construction, and, how do you think aluminum alloy would hold up for the receiver? A luger barrel is quite robust all by its self...and the only area of concern that I can see is the rear toggle pin area. If this was made adequitely robust, do you think it would withstand the repeated impacts that are demanded by todays auto pistol shooters? Again, PURE SPECULATION! Any thoughts! till....later....G.T.

[JAMES]

The right grade of aluminium alloy might hold up, but remember that Aluminum's coefficient of thermal expansion is different (much higher) than steel. In other words, it expands a lot when it gets hot. The first AR-15's & M16's had this problem. After they shot enough rounds, the receiver would expand and the bolt would lock up in it until it cooled. Also, aluminum can't be blued, but it can be anodized.

I know that a few zinc ones were supposadly (bad sp and sorry) made, that is in Jones book. He said that they thought that the zinc would not stand up to the pounding. I think a 9mm would ahve too much recoil, I'm NOT an engineer, I just was always leading them in battle...


(That is an inside joke, the engineers always say they are first in the line to clear the way and as MP's we always said we were there first to direct the traffic for them )


Ed

[schwob]

Well spoke by a True M.P.!!!!

[Ron Wood]

I am doubtful that aluminum would hold up for a Luger receiver. In full recoil, the inertia of the receiver assembly is arrested by the recoil lug on the bottom of the receiver. However, the toggle assembly is moving independenly of the receiver. When the toggle is in full recoil, the rear-most portion of the toggle strikes the frame just above the lanyard staple, arresting the rearward movement of the breech block and toggle assembly. At that point, aside from the inertia that is taken up by the main spring, a lot of the force of the recoil is absorbed by that rear part of the toggle and the axis pin holding the toggle to the receiver. If you look at the rear toggle link as a lever and the axis pin as a fulcrum, you can see that a lot of force is placed on the pin in line with the direction and force of the recoil. I would imagine that it would not take long for the pin to stretch the soft aluminum, elongating the axis pin hole in the receiver and eventually leading to fracture of the receiver at that point. Just a guess, but I wouldn't want to be the shooter.

Also one must consider the lower mass of the Barrel and Aluminum Alloy Yoke Assy. which would greatly increase the recoiling velocity of the entire "Cannon Assy. causing the toggle ears to hammer against the frame in a mercyless manner. This would also lead to early parts failure.

My Observation.

ViggoG

[HÃ?Â¥kan Spuhr]

I have seen some reicivers that was bent due to heavy loads (DWM)

I have seen one reiciver cracked due to long use.

All reicivers are partly hardend at the recoillug area and even though they are that they are still batterd there.

So if that area not had been hardend the bold wouldent been able to travel as the toggle had hammerd out the reiciver in the area where the bolt travels.


I am absolutetly convinced that aluminium regardless of quality is unsufficient for a Luger reiciver or a Luger frame if the guns should be used.


( But there is toolgrade Aluminum that is considerably harder and tougher than the Stainless steel used by some 1911 and so called lugermanufacturers.)


Regards HÃ?Â¥kan



http://www.vapensmedjan.com

HÃ?Â¥kan is exactly right on this matter.

The Aluminum allloy to which he is referring may be the 7075 ST Aluminum Alloy. And the applications for which it was used was a much more gentle application than that which has now been proposed.

However tough it this alloy may be, it still has a much greater ductility than the steels used in the luger, and would suffer deforming at points of impact and at high stress points around the Pivot Pins.

Even worse the problem of reduced mass causing greater acceleration in recoil therefor greater hammering at the toggle opening point of impact compounding the problems.

ViggoG

[G.T.]

I would have to say by popular vote, aluminum would be a real NoNo, in major luger parts construction!....light weight, and the reaction to it, are also factors to be considered, thanks to all for your input and ideas! till....later....G.T.

If you had the volume requirements of the war years and wanted to build a â??Lugerâ?� today you could do it with much less labor and cost then was required during the Luger days. Most of the components could be metal injected molded with little or no final finishing in any alloy you wanted. Its just like plastic but utilizes SS, CR steel or any alloy you could imagine. You would still bore the barrels and chambers but thatâ??s about it. You do need the high volume to justify the tooling cost. If you want a inexpensive receiver then mold it to the finished dimensions. That would be they way it would be done today.


Best regards,

Rod

[G.T.]

Hi Rod! Once you make one or two Luger parts, you want to make them all! I sometimes allow myself the fantisy of designing a luger in a modern day version! The only reason for aluminum is that it machines easy for prototype work when you are equipment light! (Another drawback to poverty!)I have closely inspected the Swiss 06/29 and came away amazed at the improvements they made to the design 70+ years ago, I agree most all parts, both major and small, would have to be cast to a near net shape! I think some parts could be redesigned, others eliminated all together! There is still a lot of room for improvement, Neat gun, nice dream! till...later....G.T.

[JAMES]

Even by modern technology, the production cost of a quality Luger would be very high in comparison to other automatics on the market today. The principal of Luger operation requires much tighter tolerances than say a M1911 Colt, or the new Barettas. Nowadays the craftsmanship of the old Lugers would simply be too expensive to produce in comparison with other autos made today. In my opinion, this craftsmanship is what makes the Luger special.

[Gene]

Hakan has observed that steel receivers can crack after long use. The same stresses will cause any aluminum receiver to crack MUCH, MUCH earlier since one basic difference between aluminum and steel is that aluminum quickly work hardens under repeated stress.