Physics & Luger loads!???

[G.T.]

Just recently the thread for the 7.65 x 19 was revisited....one of the posts mentioned some of the problems that arose with the wildcat on the 9 mm brass....in the area of function and case seperation....

My question to reloaders (and wildcatters!!) are as follows, If you used a somewhat heavy bullet for the cartridge, say 100 gr, would this not help the function, or at least make up for some of the suspected reduced inertia? Also, I noticed that the .30 Mauser sport parabellum (in the 70's)was sporting a slab side barrel, while the 9mm had a full bull barrel, do you suspect this weight reduction had a purpose in the overall function of the .30 Luger in general? What if you used a pencil thin 1900/06 type barrel, would this be a better choice for function? And last, if you size correctly, or fire form your brass, use quaility brass and neck size only, shouldn't this alleviate case seperation at the shoulder? I'm not a reloader, but I have listened in on some trouble shooting tips, and they seem to parallel this type of problem......What say ye! till...later...G.T.

[G.T.]

Hi Rick! I think your opinions are quite sound! As they have a bit (A lot!) of experience behind them! Are you going to pursue the 7.65 x19? Or do you think the niche it would fill is not necessary? For some reason it intrigues the hell out of me....I will continue to be interested until I can build one! Thanks Rick, for your insight! till...later...G.T.

[Hugh]

You can set back the barrel on your Martz navy and make one out of it!

[G.T.]

Hi Hugh, If I were going to do that, I would make a barreled receiver, or just a barrel, that had the correct front sight block! Not a bad idea! We shall see! till...later...G.T.

[HÃ?Â¥kan Spuhr]

Hi Rick


I do belive that the caseseparations easaly can be cured, but as we found the high preasure to be a big problem and the fork was so badly bent that it wouldnt freely slide over the rails we stopped our experimentation.


However it's well known that smaller case capasity gives much higher preasure so the idea is not totally problemfree how ever you do it.


Using heavyer bullets in a 7,65x19 removes some of the idea behind the 7,65x19 and the recoil comes closer to 9x19.

The heavyer bullets will of course compensate for the loss in inertia to a certain extent.


A big part of our problems is very likely to be the heavy barrel, it was a 5" 20mm oktagon barrel and that is very different from a ligth barrel.


Regards HÃ?Â¥kan Spuhr



http://www.vapensmedjan.com

[G.T.]

Hi Rick, Hugh and Panzer are pretty good buddies! But, I think I can get Tazzie to get after him!!! I like your .22 sabot idea, but I bet it would be difficult to get to function with the light bullet, but you could check that out in a standard .30 Luger....it would be fun, and fast! till...later...G.T.

[ViggoG]

A few Cents worth on common sense Internal ballistics .


One must first consider the forces that we call recoil , This is the force that open the breech on PO-8"s !


The average of a large number of Instanteanious internal

breech pressures times the difference between the largest

internal cartridge area -- and the internal area of the barrel

This multiplied by the time required for the projectile to

transit the barrel.

This is the accelerating force on the moveable barrel and breech assembly

This time force value acted on by the recoil spring determines the time and distance available to traverse the

full length of the magazine , eject the empty case, strike the buffer or stop, now accelerated by the recoil spring, return to chamber another round .


A balance of all of these forces and motions must be both

made and considered in the case of any malfunction .

Failure to do so results in arriving a working combination through pure guesswork and luck, experience is also usefull .


The weight of the Projectile bears only on the acceleration portion of the problem Via of the changes it makes in the time of transit and only through this will projectile mass effect the recoil force on the breech.


The complex forces entered into the formula by the toggle linkage so complicates the problem that it confuses all but the best of Ballistic Analyists


Just a thought to consider .

I hope it produces enough mud to make the un-inniated

THINK, THINK, THINK !!!!!


ViggoG

[ViggoG]

I made a error in describing the preessure that develope the recoil I really should have said the pressures times the internal barrel area. and not the "difference between"

because that effects the force to consider on the toggle pin


apologies all around


ViggoG

[Patrick]

This thread has been of great interest. The only way to learn is to read all about it from people who know more than I do (which isn�´t a lot). Werle has recently told me that work on a small bullet wildcat round has experienced a setback recently as two promising rounds, developed in England and in Czecheslovakia had failed to work the action on various pistols reliably. I have an Erma .22 conversion unit permanently fitted to a Luger receiver with a bull barrel. It�´s only a blowback and even that does not work reliably with standard match 22. ammunition - and only slightly better with HV. I have experimented with different springs to no avail.Nil desperandum. Patrick

[HÃ?Â¥kan Spuhr]

A BIG part of your .22 problems is your bullbarrel.

This is due to your pistol is not a "just" a blowback, it also have to cycle back and forward the hole fork and barrel unit.

Its very possible that it would work better on a lighter barrel, the barrelweight contra recoilsrpings on all Lugers are really important


Regards HÃ?Â¥kan Spuhr



http://vapensmedjan.com

[Patrick]

Hakan (sorry but I can�´t find a way of getting the "o" over the "a" -I�´ve only just found out how to do an Umlaut!). I�´m sure you must be right. But the conversion unit uses the same spring that is used in the P 38 (which uses two of them). The conversion unit spring is shorter - so I have been experimenting with different lengths. If it�´s too short, it doesn�´t close and if the spring is too long, it doesn�´t cycle. There�´s no in between. Patrick

[Hugh]

have you tried getting a Wolf 10% extra strength spring and cuttin it to the correct length? May give you a little extra "OOmph"

[Thor]

That is a thought! A cheap fix if it works! Thor

[John Sabato]

[ViggoG]

I think that J. S. Has given up the secret of

how to produce Umlots ect. -- unlimited ---


All that may be necessary is to make a list

of the Non - English characters as John has .

After obtaining a full list of these letters

we can now copy and past individual letters

into any word to make it lingually correct .

THANKS JOHN FOR THINKING UP THE FIRST MOVE .

ViggoG

[BILL]

I think that anyone with Windows 98 can also access foreign characters. �?�?�¤�¶�°�? are some of the German characters available. Not sure about Mac users though.

[HÃ?Â¥kan Spuhr]

Is it a ww2 original kit or is it new?


IF it is new you have to polish all the parts and polish the feedramp as the finnish not is sufficiently good.

Regards HÃ?Â¥kan

[John Sabato]

And it is only possible inside Microsoft Word, not a browser.


Whatever works for you...


-JS

In German, an umlaut signifies an "e" after the vowel it is placed over.

During the war, many German typewriters were not fitted with the umlauten keys, and thus, the "e" after the vowel became standard practice in most writings.

So, to be correct in German, you can always write �¼ as "ue",

�¶ as "oe", and �¤ as "ae".

Not so sure about Swedish, but that's how it works in German.

Hope this helps.

[ViggoG]

Thanks Hannah, your addition is most enlightening

We need all the help that we can get .

ViggoG