Cartridges are too short

[Puretexan]

Ok I have read a bunch , and the length of a 9mm makes
a difference on weather a Luger will function properly.
If you take a 9mm Luger and change the barrel to .30
the only change you might need to make is to change the
spring. If what everybody is saying is true the really shorter .30 bullets should never work in a pistol that
was 9mm. Right? Same magazine, same everything but
the barrel.
I know I'm like a 2 year old and ask too many questions.

Paul

[rhuff]

The SAMMI max OAL for a 30 Luger RNFMJ is 1.175 in.

The SAMMI max OAL for 9mm 115/124 RNFMJ is 1.169 in.

[Sieger]

Originally Posted by rhuff

The SAMMI max OAL for a 30 Luger RNFMJ is 1.175 in.

The SAMMI max OAL for 9mm 115/124 RNFMJ is 1.169 in.

Hi!

DWM existed a long time before SAMMI stuck its finger in the potl.

Proper OAL of an original DWM factory 7.65 mm, round nose cartridge, at was 1.173 inches.

All of the current 7.65 Parabellum rounds I have measured are much, much shorter than what is required for 100% reliable function.

Sieger

[Chickenthief]

Originally Posted by Sieger

Hi!

DWM existed a long time before SAMMI stuck its finger in the potl.

Proper OAL of an original DWM factory 7.65 mm, round nose cartridge, at was 1.173 inches.

All of the current 7.65 Parabellum rounds I have measured are much, much shorter than what is required for 100% reliable function.

Sieger

Prvi/PPU come awfully close!

[Chickenthief]

The little ones are quite long

[DonVoigt]

I believe your premise is flawed; you over simplify what works and why.

Have you tried "standing" several 9mm and several(brands) of 7.65mm side by side- or measuring the OAL?

I've gone so far as to sort WWB rounds by length, to see if a particular luger liked "long or short" better. Yes, the rounds vary, QC just isn't what it could be.

You will find that the OAL varies significantly from brand to brand and lot to lot.
Some pistols are not very sensitive to OAL, others are- not much rhyme or reason to it.

Did you buy the Goertz and Sturgess CD? There is a whole chapter on ammo, another on magazine differences and changes(improvements".

A "generalization" , which often can get one in trouble, regarding 7.65mm/.30 luger is that pistols in that caliber are somewhat or even noticeably more sensitive to ammo. Whether it is velocity, weight, or OAL. JMHO.

[Puretexan]

Ok after standing a 9mm and a .30 next to each other , they are almost
the same legth. Guess its a optical illusion that one is a lot shorter than
the other. Humm missed that one pretty good, sorry

Paul

[Chickenthief]

No need to be sorry!
Absorb, learn get smarter

[alanint]

Originally Posted by Chickenthief

No need to be sorry!
Absorb, learn get smarter

Sadly, some people merely become more informed, but not necessarily smarter!

[Sieger]

Originally Posted by alanint

Sadly, some people merely become more informed, but not necessarily smarter!

Well,

The proof is in the pudding; as smart is what smart does!

Sieger

[mrerick]

The Luger was initially designed to chamber the .30 Luger / 7.65mm Luger round.

Later, the Navy, wanting a more powerful "military" class round, requested the 9mm. Modifications were made, but mainly to the barrel and recoil spring.

Remember, for many things Luger the FAQ document is your friend!

Marc

[Dwight Gruber]

There is another pertinent difference between the 7,65 Parabellum cartridge and the DWM 9x19 round (actually, a couple of pertinent differences).

With the too-short 9mm round, the bullets snag on the top edge of the chamber. The 7,65 bullet, being narrower, does not present its ogive to the top of the chamber, so does not get caught up even if the OAL is a fraction shorter.

The original 9x19mm design used a truncated-cone bullet. Although not specifically designed this way for proper feeding, it coincidentally successfully mimics the ogive properties of the 7,65mm round. Some modern Winchester 9mm ball ammunition has a gently truncated-cone bullet.

--Dwight

[Sieger]

Originally Posted by Dwight Gruber

There is another pertinent difference between the 7,65 Parabellum cartridge and the DWM 9x19 round (actually, a couple of pertinent differences).

With the too-short 9mm round, the bullets snag on the top edge of the chamber. The 7,65 bullet, being narrower, does not present its ogive to the top of the chamber, so does not get caught up even if the OAL is a fraction shorter.

The original 9x19mm design used a truncated-cone bullet. Although not specifically designed this way for proper feeding, it coincidentally successfully mimics the ogive properties of the 7,65mm round. Some modern Winchester 9mm ball ammunition has a gently truncated-cone bullet.

--Dwight

Dwight;

As long as I follow the correct procedure in properly determining OAL, I've never experienced jamming with any TC or RN bullet of proper weight and configuration (most typically available brands).

The correct OAL for the RN 9mm bullet is also 1.173 inches, NOT the later derived SAMMI, so often misquoted, 1.169 inches.

For a review, our readers might enjoy reading, in the Reloading Sticky Section, "How to Determine Proper OAL with a New Bullet" as it will answer many of their questions.

Sieger

[Sieger]

Originally Posted by Dwight Gruber

There is another pertinent difference between the 7,65 Parabellum cartridge and the DWM 9x19 round (actually, a couple of pertinent differences).

With the too-short 9mm round, the bullets snag on the top edge of the chamber. The 7,65 bullet, being narrower, does not present its ogive to the top of the chamber, so does not get caught up even if the OAL is a fraction shorter.

The original 9x19mm design used a truncated-cone bullet. Although not specifically designed this way for proper feeding, it coincidentally successfully mimics the ogive properties of the 7,65mm round. Some modern Winchester 9mm ball ammunition has a gently truncated-cone bullet.

--Dwight

Dwight;

Taking a good look at that very angled grip, I think you will find that the cartridges loaded toward the bottom of the eight shot magazine cause the upper most cartridges to cant downwardly. This downward canting is the source of the infamous "Luger Jam".

This is why proper OAL is so critical with this design.

This is true for both the 9mm and the 7.65mm.

Sieger

[DonVoigt]

OP should change his title to "cartridges" not "bullets"; I believe that the OAL length of the cartridge is the subject of this thread.

To do so, select edit, then "go advanced"; then you can edit the title.

[cirelaw]

https://en.wikipedia.org/wiki/7.65%C3%9721mm_Parabellum

[ithacaartist]

This is interesting. If a lowball bid will yield some .30 ammo that is other than the readily available standard fare, I will add it to my little collection. I measured some, and here are the results:

Winchester White Box......................1.150 x

Winchester Red and Yellow Box.......1.150 x

Remington Green and Yellow Box.....1.131 x

Remington Dark Green Box..............1.134

Fiocchi Gray Box Brown Printing.......1.127 x

Fiocchi Purple Box............................1.119 x

According to the discussion, I'm amazed that any of this stuff works at all, but my shooter works without complaints.

[DonVoigt]

Originally Posted by ithacaartist

This is interesting. If a lowball bid will yield some .30 ammo that is other than the readily available standard fare, I will add it to my little collection. I measured some, and here are the results:

Winchester White Box......................1.150

Winchester Red and Yellow Box.......1.150

Remington Green and Yellow Box.....1.131

Remington Dark Green Box..............1.134

Fiocchi Gray Box Brown Printing.......1.127

Fiocchi Purple Box............................1.119

According to the discussion, I'm amazed that any of this stuff works at all, but my shooter works without complaints.

You are indeed "blessed", it all of those will work!

[Sieger]

Originally Posted by ithacaartist

This is interesting. If a lowball bid will yield some .30 ammo that is other than the readily available standard fare, I will add it to my little collection. I measured some, and here are the results:

Winchester White Box......................1.150

Winchester Red and Yellow Box.......1.150

Remington Green and Yellow Box.....1.131

Remington Dark Green Box..............1.134

Fiocchi Gray Box Brown Printing.......1.127

Fiocchi Purple Box............................1.119

According to the discussion, I'm amazed that any of this stuff works at all, but my shooter works without complaints.

Hi;

Can you shoot a full magazine of 8, with no jamming, with all of these?

Though I'm not doubting your honesty, I would seriously doubt a Luger would pull this off.

Sieger

[ithacaartist]

Originally Posted by Sieger

Hi;

Can you shoot a full magazine of 8, with no jamming, with all of these?

Though I'm not doubting your honesty, I would seriously doubt a Luger would pull this off.

Sieger

I must confess that my statement is not in absolute terms! But in response to your question, I'd say noticeably more often than not. I used the gun in IDPA matches with that Berdan primed Scandinavian surplus ammo that Samco sold before they closed the business. The combination presented no consistent issues, though I can't say there weren't more stoppages than the one round I do remember dropping the mag to clear.

I did have some trouble with some boxes of Fiocchi SJSP rounds which seemed to be gritty on the business ends, with a thin film of corrosion. They would bind in the mag, until I shined up the ends again. I'm glad that is gone.

Maybe my love for the gun inspires selective validation! So, I will do a test and pay attention. I usually don't shoot the old, odd stuff, but use Fiocchi at home, where I can save the boxer primed brass. I will shoot two MecGar mags of each over the next few days and report back with results. Here are two more OAL:

Swedish surplus........1.167

Norma.....................1.151