What is the influence of overal length?

[alterfritz]

Hello all,

I would like to ask what is the influence of the overall length of a 9mm cartridge on it's mechanical reliability? Is there a consensus about the "right" length?

The reason I'm asking is that I tried reloaded ammunition purchased at my local range today (I know, I know I should not have done this but I guess I'm the kind of guy who needs to make his own mistakes ). Anyway, compared to my Winchester white box ammunition, the bullets where a bit short, by my guessing about 1 mm, the case were of same size.

While I had no trouble with this combination of magazine and Winchester ammunition, this reloaded one gave me a bad malfunction during the last few rounds. Somehow an unfired round was chambered and the toggle stayed open, could not be closed and it appeared that the next round was in a position that held the toggle open. I wasn't able to pull the magazine out, but somebody else with more pistol experience helped me and got it out, probably simply by using more force than I did. I fired a magazine of Winchester after this with no problems.

So my first question is, are these kinds of malfunctions typical with shorter bullets? And my second one is, can anybody explain to me what went wrong mechanically? I would like to understand what caused this jam.

Sorry if these questions sound noob, I know I should not have tried the reloaded ammunition in the first place, but since it happened, I would like to understand what exactly happened

[Steinar]

I always check the shell of reloads with a caliper to see if it has been stretched. Believe it's worse if it's too long, leaving the bullet with too little free run.

In your case it seems as if it's just the bullet that is shorter by 1mm, that's not much.. as long as it's a round nose, I don't think that’s your problem. As you probably know, the Luger scrupulous about it's ammunition. Bullet weight or powder used is more likely the cause I believe.

[John Sabato]

Some Luger magazines are very sensitive to over all length (OAL) of the loaded round... They can't be too long, or too short.

P.38 magazines, on the other hand, often will sometimes feed even empty cases... go figure!

[Sieger]

Originally Posted by John Sabato

Some Luger magazines are very sensitive to over all length (OAL) of the loaded round... They can't be too long, or too short.

P.38 magazines, on the other hand, often will sometimes feed even empty cases... go figure!

John:

Both of my P-38s will feed only ball ammo with any type of reliability. Hollow Points or Truncated Cone bullets jam constantly and consistantly.

Sieger

[alterfritz]

Yep, I don't know which load they used of course. It was the original magazine that came with the gun, but then the second magazine has a little dent to it too. I currently have two mec gear magazines with GT, from what I read elsewhere int he forum they should do a good job after the springs and bottoms have been exchanged.
I'm not so much puzzled about the round in the chamber because that was actually in the correct place but the magazine somehow was stuck and needed some force to pull it out. Thanks for the advice though, I will wait for the two magazines and see how they do with winchester ammonition

[Sieger]

Originally Posted by alterfritz

Hello all,

"I would like to ask what is the influence of the overall length of a 9mm cartridge on it's mechanical reliability? Is there a consensus about the "right" length?

"...this reloaded one gave me a bad malfunction during the last few rounds. Somehow an unfired round was chambered and the toggle stayed open, could not be closed and it appeared that the next round was in a position that held the toggle open. I wasn't able to pull the magazine out, but somebody else with more pistol experience helped me and got it out, probably simply by using more force than I did. I fired a magazine of Winchester after this with no problems.

"So my first question is, are these kinds of malfunctions typical with shorter bullets? And my second one is, can anybody explain to me what went wrong mechanically? I would like to understand what caused this jam."

Hi:

With a Parabellum, OAL is a very critical element for proper function (being able to fire, from a full 8 round magazine, at least 1,000 rounds without a jam).

Your mechancal question first. Please note the steep angel in which the magazine sits in the frame. Luger designed the grip for a perfect fit in the human hand at a price, that being, the aforementioned steep angel of the magazine. The cartridges just don't move upwardly, as is the case with the P-38 or Colt 1911, rather, they "slide up" the interior of the magazine at a very steep angel. This sliding action is one reason the spring of a Luger's magazine needs to be so incredibly strong as compared to a P-38 or a Colt 1911.

With proper OAL, all 8 of the cartridges are perfectly alligned, in a parallel fashion, within the magazine, and there is no binding during the feeding (sliding) process. With the OAL too short, you will note that the top cartridges cant downward just a bit. This slight cant downward causes a split second delay in the upward movement of the top cartridge upon firing, causing just the jam you have described above!!

Here are your proper, original DWM specification OALs:

Round nose 9MM and 7.65: 1.169 to 1.173

Truncated Cone 9mm: 1.14 to 1.15

If you reload, try these lengths in your MecGar Magazines, as they will work perfectly. Yes, these lengths are way too long by modern reloading manual standards, as most commercial loaders of modern 9mm ammo have lost touch with the need for the in spec. lengths for the Parabellum pistols.

Yes, proper powder type and charge are also necessary to make a Luger function properly, as well as, in spec. magazine and main springs.

Sieger

[John Sabato]

Seiger,

I once owned a ac 41 P.38, that would literally feed empty cases and homemade snap-caps that had no projection where the projectile would be... if I worked the action...

It would have been a perfect basis for blank or re-enactor's gun, but I sold it as part of a trade in 1975... :sigh: The bore was perfect, and it was all matching parts, but it had been reblued, so it wasn't a collector item... I got a new in the box Colt National Match .45 for it and a P-38 parts gun that I had shortened to a snub nosed barrel...sort of like a P-38K.

Wish I had both of the P-38's back... I sold the Colt in 1976 when I left the Army Marksmanship Unit at Fort Gordon, GA for an overseas assignment in Italy where I couldn't take my military caliber guns.

[alterfritz]

Thanks Sieger, thats really a very interesting description. At least I understand now how critical the length is. I must admit I did not take the angle into account when I was thinking about the cause of the malfunction. I guess I will have to get a calipher to check each new type of amunitioin. Whitebox Winchester is sometimes hard to get around here, I don't know why, but I will stay away from the reloaded ones form the range.
I don't reload myself so I don't know much about that yet. Maybe I will look into that if I run into problems with the Winchester ammunition, but from what I read here, that one should be fine.
Or is there really a difference in mechanical performance that makes reloading worth while?

[Sieger]

Originally Posted by alterfritz

.
Or is there really a difference in mechanical performance that makes reloading worth while?

Hi:

Custom reloading for any firearm really brings out the accuracy and performance of it to its peak!!

Commercial ammo is loaded to averages, so, that's typically what you get from it, average performance!

If you have the time and talent, reloading is one of the most rewarding hobbys around.

Sieger

[alterfritz]

Ok I might look at it in the future when I have some time. One thing I already know is that there's a lot of reading to be done before I touch it, it doesn't look trivial.

[LSP972]

Originally Posted by alterfritz

it doesn't look trivial.

It isn't. But its not rocket science, either. The key is paying attention to detail.

My newly acquired 1914 DWM is 100% reliable with both
Federal American Eagle 115gr ball and WW "white box" 115gr ball. It chokes consistently on my pet reload, which is a Precision Delta 115gr ball bullet over 4.2 of WST. This load functions fine in the other half-dozen 9mm pistols (all "modern") that my family and I shoot.

The type of malfunction I'm seeing in the Luger is a failure to feed. The cartridge OAL is 1.145"; the factory ball cartridges are 1.165". This is in line with Sieger's information above.

I batch-load by caliber; I would rather not constantly be changing tool heads, etc., on the Dillon. I'll load several thousand rounds before switching things. I shoot mainly .45, but my wife and grandsons can lay waste to an ammo can full of 9mm...

Anyway... next time I load 9mm, I'll move the OAL out by twenty thousandths, and use Winchester bullets. The Precision Delta bullet has a more shallow ogive than "standard". That could possibly be a contributing factor.

The point is, I'll have fun tinkering with my load parameters, trying to find one that works. And not only is rolling your own enjoyable, it makes tremendous economic sense these days. You have to buy your components in bulk to realize major savings, but the potential is there.

I frequent a "local" shooter's board. There are many posts of guys giving scouting reports on which store has ammunition, at what price. Lately, an undertone of desperation is creeping into these posts, as they are finding less and less available, at ever-increasing prices.