LugerForum Discussion Forums - Chambering Problems

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TBeardmore

08-21-2002 11:44 PM

Chambering Problems

Hi everyone!

Well, I took my recently acquired byf 42 to the range today. I'm disappointed by the problems I had with it chambering rounds. Using two different mags and using factory "American Eagle" ammo, I consistently had problems chambering rounds.

Some of the rounds chambered too high in the breech, holding the bolt open. Others "stove-piped" with the bullet end of the round sticking out of the chamber between the bolt and the breech. Other times, when the round loaded properly and I fired the pistol, the brass ejected, but no round was stripped from the magazine.

I'm not sure what the trouble is, but I purposely selected lower-power ammo for my first outing, because I was wary about using higher-power rounds in a used pistol (even though I'd had it checked by a gunsmith first). I'm going to go to the range again this weekend with a box of higher-power ammo to see if it improves the results.

What say you all? Should I be looking for another cause of the chambering problems I experienced?

Thanks, as always!
Tom

Thor	08-21-2002 11:53 PM

Stronger mag spring, first! Also Do a power check, load one round! Fire and check to see if hold open works. Do this test 5 times, if hold open locks every time, ammo has enough power. My guess is the spring in the mag is too weak, a common problem and the ammo is a little under powered for that particular Luger!

wterrell

08-21-2002 11:53 PM

Tom,

Ammo is the answer.

Lugerdoc

08-22-2002 08:55 AM

Tom, I agree that hotter ammo should cure your problem, since these late WW2 PO8s were set up with a stronger recoil spring to handle SMG ammo. If this is primarily a shooter, polishing the chamber and feed ramp would probably help. Tom H.

policeluger

08-22-2002 01:58 PM

good advice above, but only very light polish, do not grind away metal. Now I may get dinged on here, but as a gunsmith (25years) collector and shooter of Lugers...I have found Blaser ammo to be all around some of the most reliable ammo there is.

John Sabato

08-22-2002 02:11 PM

the ammo that walmart sells for $11.00 a hundred has also gotten some good reviews on the forum.

AGE	08-22-2002 06:36 PM

Guys,

I love that Walmart Winchester ammo--that's all I shoot in my Luger. However, PMC 124 grain and Wolf 147 grain Russian (not recommended!!!) have a good bit more oomph.

rabbrt2

11-04-2003 06:29 AM

Tom,

Can you please provide some details on the proper procedure for polishing the chamber. Do you recommend the use of a polishing compound such as Flitz. How do you apply it (Dremel tool)?

Thanks,

Robert

Lugerdoc

11-04-2003 08:17 AM

Robert, I agree with police lugers that you don't want to over polish the PO8 chamber. If it is pitted or damaged, this could cause excess friction and make extraction difficult. If eroded, and your case is expanding, your only real alternative is to replace the barrel. A light polish of the feed ramp done with a dremel and light abrasive, will sometimes help, where the rounds want to "smokestack" on feeding. Tom

unspellable

11-04-2003 08:38 AM

First, a "chambering problem" means the cartridge will not easily enter the chamber when hand fed. It does not sound like that is what we are talking about here. Failure to feed properly can be due to several things. First and foremost, factory loaded ammo is too short in the OAL to meet the original specs. This causes the cartridge to rise in the magazine with the nose too low. This may cause it to drag in the magazine. It may cause the cartridge nose to bounce up off the ramp.

The 9 mm Luger with a four inch barrel does not need "hotter ammo", this is a problem that belongs to the 7.65 caliber. Both calibers can benifit from a handload set to the correct length.

As with any self loader the magazine can be defective.

Try different ammo and different magazines first. Get a real undertstanding of the problem before you start modifying anything. Beware of local "gunsmiths" who "think" they know how a Luger works. Try it with a handload set to the correct OAL before you modify the ramp or chamber. You might also check the recoil spring. I have opened up a number of Lugers and found a bewildering assortment of modifiied and hacked up recoil springs. (Remember the "gunsmith" who "thinks" he knows how a Luger works?)

Sieger

11-04-2003 10:43 AM

<blockquote>quote:<hr />Originally posted by unspellable:
First and foremost, factory loaded ammo is too short in the OAL to meet the original specs. This causes the cartridge to rise in the magazine with the nose too low. This may cause it to drag in the magazine. It may cause the cartridge nose to bounce up off the ramp.
<hr /></blockquote>Amen:

If you handload, here are the proper OALs for the Luger. I know, these are a bit longer than standard, but that's why they work, they are the original lengths.

Round Nose 1.175 inches

Truncated Cone Flat Point 1.15 inches

Try to use bullets that come to more of a "point" at the front. Excellent examples are the newer Hornady hollow points in both 115 and 124 grains.

A luger that is not functioning properly can be a real disapointment, while one that is, is a heck of a lot of fun to shoot.

Sieger

rabbrt2

11-05-2003 12:28 AM

I take your points regarding handloading. This is my first Luger, and I bought some cheap UMC ammunition, maybe that's my problem.

Although the fired brass from about 1/10 inch from the mouth back looked a little
rougher and maybe even a little more expanded than I would expect 9mm brass to look. Almost like fine sand paper was rubbed along the length
of the case, maybe all old luger chambers are like this?

Robert

Dwight Gruber

11-05-2003 02:20 AM

Robert,

The 9mm case is ever so slightly tapered. The chamber of a Luger, however, is almost straight-sided, with a slight "step" near the front of the chamber where it constricts to the diameter of the front of the case. A blueprint was posted on the Forum recently which illustrates this very well, you can probably find it in a search, or maybe John Sabato will ring in and tell us where he put it.

On the Lugers I shoot, at least, this leaves a characteristic ring near the front of a fired case, where it expands a bit into the cylindrical chamber (as you note) and the case is "dirty" where the powder blows back into it a bit.

When I started shooting Lugers I went through quite a series of practical tests to determine the best functioning ammunition. UMC was right near the bottom of the list, being nearly 100% disfunctional, right along with Speer and most of the gun show reloads I came up with.

At the risk of repeating myself enough times to bore everyone to death, I shoot Walmart Winchester, S&B, and CCI Blazer in three different Lugers (sometimes a fourth, if I break out my nickel-plated byf) with 100% reliability, somewhere between 400-600 rounds a month depending on how often I get to the range.

I use Mec-Gar magazines almost exclusively, and this probably has something to do with it (my magazine tests revealed that most of my original mags malfunctioned with anything I put in them).

I'm sure that some people reload for the perfection in it, my guess is that it can be pretty satisfying. 9mm ammo is so cheap that, in my shooting circumstances, it hardly seems worthwhile to take up yet -another- hobby.

--Dwight

unspellable

11-05-2003 08:18 AM

Dwight, you raise an interesting point. DWM experimented with different configurations before settling on the straight tapered case we all know and love. One of the experimental versions was a straight sided case with a very slight bottle neck. Your comments make me wonder if they just continued to use the bottle necked reamer forever after.

Johnny C. Kitchens

11-05-2003 08:24 PM

Too bad you don't live a bit closer to me. I have a byf 42 that did those sort of things. A Swiss magazine really cleared it up. If you lived closer we could get together and you could see. I bet my Luger would act like yours with your magazine, and yours would shoot great with my magazine. I've got a magazine article from a few years ago, where the author decided to try and remedy a Luger malfunctioning. He got all sorts of recommendations, but he tried shimming the spring in the magazine. First time I had seen this. He could only get five rounds in the magazine, but the gun worked perfectly...

Sieger

11-05-2003 10:30 PM

<blockquote>quote:<hr />Originally posted by Johnny C. Kitchens:
Too bad you don't live a bit closer to me. I have a byf 42 that did those sort of things. A Swiss magazine really cleared it up. If you lived closer we could get together and you could see. I bet my Luger would act like yours with your magazine, and yours would shoot great with my magazine. I've got a magazine article from a few years ago, where the author decided to try and remedy a Luger malfunctioning. He got all sorts of recommendations, but he tried shimming the spring in the magazine. First time I had seen this. He could only get five rounds in the magazine, but the gun worked perfectly...<hr /></blockquote>Johnny:

Do you have a way to precisely measure the inside length of your Swiss magazine? If so, I'd really like to know just how long it is on the inside.

Sieger

Sieger

11-05-2003 10:36 PM

<blockquote>quote:<hr />Originally posted by Dwight Gruber:

I use Mec-Gar magazines almost exclusively, and this probably has something to do with it (my magazine tests revealed that most of my original mags malfunctioned with anything I put in them).

--Dwight<hr /></blockquote>Dwight:

Do you have a precise way to measure the inside length of your Mec-Gar magazine. If so, I'd really like to know it.

Sieger

Dwight Gruber

11-06-2003 01:56 AM

<blockquote>quote:<hr />Originally posted by unspellable:
One of the experimental versions was a straight sided case with a very slight bottle neck. Your comments make me wonder if they just continued to use the bottle necked reamer forever after.<hr /></blockquote>Unsp.,

The chamber is not really bottlenecked. As you can see in the blueprint, it really is a cylinder from the breech, 9.85mm diameter; the step is an abrupt reduction to 9.75mm, with a slight taper to 9.7mm at the chamber mouth.

One wonders why they did that, and if the chamber was reamed with one reamer, or if it was done in two stages.

I have noted that in some of my Lugers the step is very pronounced and strong, and in others it is hard to see and isn't completely circumferential. Don't know if this is a result of wear or manufacturing practice, I have a hard time believing that inspectors would let this pass...

--Dwight

http://forums.lugerforum.com/lfuploa...erdiagramm.jpg

Dwight Gruber

11-06-2003 02:04 AM

Sieger,

Can't say that I have a really precise way, closest I can come is 27.25mm (give or take a tenth or so) from the front of the magazine to the spine, perpendicular to the magazine front.

--Dwight

Sieger

11-06-2003 03:37 AM

<blockquote>quote:<hr />Originally posted by Dwight Gruber:
Sieger,

Can't say that I have a really precise way, closest I can come is 27.25mm (give or take a tenth or so) from the front of the magazine to the spine, perpendicular to the magazine front.

--Dwight<hr /></blockquote>Dwight:

You got me a little interested, so I ordered 2 of them tonight.

How do you cure the step-feeding problem if all of the commercial ammo is loaded too short?

That's easy, you adjust the interior length of the magazine to work with the standard length ammo (it's only off by .006 anyway). Did they do this with their new magazines? Well, I'll just see. They certainly seem to have done something different!!

Sieger

Sieger

11-06-2003 03:43 AM

Dwight:

If you compair a Luger's chamber to that of, let's say, a P-38's, you will note that the P-38's is almost a sloppy fit compared to a Luger's.

Headspacing on the Luger is precise and somewhat tight, just as it should be.

Question: Do the late model Inter-Arms Mauser Parabellums still have the step, chamber feature?

Sieger

rabbrt2

11-06-2003 01:48 PM

I feel better that the "problems" I observed may not be a indemic to to my Luger!

I have ordered some Mecgar magazines and some Cerro safe to make a mold of the chamber. I will also try different ammo as suggested.

Boy this forum is such a great learning tool! Thanks to all for the feedback.

Robert

Johnny C. Kitchens

11-06-2003 08:30 PM

There is a reason for the step in the 9mm chamber. The round headspaces off of the mouth of the case. As far as a precise measurement of the magazine, no problem. I've got a set of calipers. I've got four different kinds of magazines, so here are the measurements.

My FXO - 1.069"
Swiss - 1.0695"
70's Mauser - 1.065"
Mec-Gar - 1.0625"

I measured from the middle of the back of the magazine to the middle of the curve in front, inside to inside dimensions. Interesting variations...

Sieger

11-07-2003 02:12 AM

<blockquote>quote:<hr />Originally posted by Johnny C. Kitchens:
There is a reason for the step in the 9mm chamber. The round headspaces off of the mouth of the case. As far as a precise measurement of the magazine, no problem. I've got a set of calipers. I've got four different kinds of magazines, so here are the measurements.

My FXO - 1.069"
Swiss - 1.0695"
70's Mauser - 1.065"
Mec-Gar - 1.0625"

I measured from the middle of the back of the magazine to the middle of the curve in front, inside to inside dimensions. Interesting variations...<hr /></blockquote>Johnny:

Well then, it sounds to me like Mec-Gar has, indeed, shortened up the interior of the magazine to address the Step-feed problem with modern spec ammo!!!

Original OAL for Ball Ammo 1.175
Current American Standard 1.169
-----
Difference 0.006
=====

FXO Interior Length 1.069
Mec-Gar Interior Length 1.0625
------
Difference 0.0065
======

This little discovery may be very, very helpful to those experiencing the infamous OAL problem. They should now confine themselves to firing ammo that is max. spec. length, that being 1.169 inches long.

As I've said, I have two of these magazines on order and will have plenty of time to experiment with them very shortly.

THANKS A MILLION!!!

Sieger

Sieger

11-07-2003 02:24 AM

DWIGHT:

"At the risk of repeating myself enough times to bore everyone to death, I shoot Walmart Winchester, S&B, and CCI Blazer in three different Lugers (sometimes a fourth, if I break out my nickel-plated byf) with 100% reliability, somewhere between 400-600 rounds a month depending on how often I get to the range."

PLEASE FEEL FREE TO BORE THE HELL OUT OF US ANY TIME YOU LIKE. YOU MAY HAVE JUST SOLVED ONE OF THE MOST ANNOYING PROBLEM WE SHOOTERS HAVE WITH THE LUGER, THAT BEING THE OAL PROBLEM!!! <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

"I use Mec-Gar magazines almost exclusively, and this probably has something to do with it (my magazine tests revealed that most of my original mags malfunctioned with anything I put in them)."

Can you give us precise measurements of the OALs of your Winchester, S&B and Blazer ammo? <img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" /> <img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" /> <img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" />

Sieger

unspellable

11-07-2003 08:21 AM

Johnny, the cartridge does not headspave on the step. The step is 14.1 mm from the breech face while the headspace is 19.1 mm at the step between the end of the chamber and the beginning of the barrel. A point to note is the SAAMI max case length is 19.15 mm, another point of discrepancy.

So I am still wondering if they went to the straight tapered case but retained the original bottle necked chamber. The bottle neck was very slight.

At the risk of being called an iconoclast, I have a theory that the 9 mm round was developed directly from the 7.65 Borchardt/7.63 Mauser case without the 7.65 Parabellum case being involved, as opposed to the more usual theory that the 9 mm is a necked up 7.65 Parabellum case.

Sieger

11-07-2003 02:46 PM

<blockquote>quote:<hr />Originally posted by unspellable:
Johnny, the cartridge does not headspave on the step. The step is 14.1 mm from the breech face while the headspace is 19.1 mm at the step between the end of the chamber and the beginning of the barrel. A point to note is the SAAMI max case length is 19.15 mm, another point of discrepancy.

So I am still wondering if they went to the straight tapered case but retained the original bottle necked chamber. The bottle neck was very slight.

At the risk of being called an iconoclast, I have a theory that the 9 mm round was developed directly from the 7.65 Borchardt/7.63 Mauser case without the 7.65 Parabellum case being involved, as opposed to the more usual theory that the 9 mm is a necked up 7.65 Parabellum case.<hr /></blockquote>Dear Unspellable:

I just read last week that there were two reamers involved in the chambering process. Why this was done...?

Well, the practice persisted from 1902 through 1942 so the German Engineers must have had a good reason for it.

For the origins of the 9mm casing, study Luger's 480 and 480A casings, as these were, indeed, bottle neck 9mms.

Sieger

Dwight Gruber

11-09-2003 09:59 PM

<blockquote>quote:<hr />Originally posted by Sieger:
I just read last week that there were two reamers involved in the chambering process.[/QB]<hr /></blockquote>Sieger,

Where did you come across this?

--Dwight

Dwight Gruber

11-10-2003 12:31 AM

I'm afraid that I don't have the tools to precisely measure the oal of the Winchester, S&B, or Blazer ammunition.

I would like to take a dissenting position to the theory that overall length of the cartridge in the magazine is the primary contributor to Luger malfunction in the 21st century. I am of the opinion that the condition of the magazine feed lips is the crucial factor, and the magazine spring is an associated consideration (as may be bullet shape).

Earlier in this discussion I reported my experiments with magazines and ammunition, settling on the MecGar magazines and ammunition selection which functions best in my variety of shooting-quality Lugers. This was entirely a methodical empirical test.

The original magazines I tried were a random selection which had come with various Lugers I have purchased. Observing these loaded magazines, it was apprarent that the feed lips had variously become weak or bent, that the topmost cartirdge was not held firmly in position, or was not held at the proper angle. And feed angle seems to be the crucial parameter here, if the bullet nose does not approach the breech precisely, it will misfeed.

Having magazines and ammunition which work acceptably might be the end of the matter, except for some experiences I have had since.

I obtained an fxo magazine (until I traded it) which I used to shoot, along with my Mec Gars, and it proved just as reliable. fxo mags are extruded metal, very solid, and have very stiff feed lips.

I recently picked up a proper magazine for my S/42 shooting Luger, blued metal (rolled&folded) tube, aluminum base. Although I did not buy it as a shooting magazine (judging by my previous experience), I have used it several times with no reliability problems.

If the oal of the ammunition was the primary factor, one would expect these magazines to fail as much as the original mags in my first test. In fact, conventional wisdom has it that fxo magazines are excellent shooting magazines.

With one Luger purchase I acquired another aftermarket magazine, not a Mec Gar, in fact I can't find any manufacturer on it. It is fairly leightweight, and only holds seven rounds. I have compared it to a Mec Gar, and it seems to be the same internal length.

I tried using this magazine shooting several times, suffering malfunctions each time. I looked at it closely and noticed that the feed lips were spread a little, allowing the cartridges to rest at too steep an angle. I unloaded it and pressed the feed lips against the shooting bench (did I mention that it is lightweight?) which bent them in a bit. I re-filled the magazine and noticed that the cartridge angle was better, and proceeded to use it without problem. It has functioned without malfunction ever since.

There are some other magazine variables which affect the angle of the cartridge as it enters (or doesn't enter) the chamber. Take all of your magazines and insert one round, then compare the angle which the magazine follower holds this round. This may have an effect on the availability of the last round to chamber reliably, or even be picked up by the breechblock.

The magazine spring obviously has an effect on the angle the top cartridge rides in the feed lips, as it presses the round more or less firmly into place.

As I have been working with magazines while writing this post, someting else has occurred to me. Some magazines work much more smoothly than others, which has an effect on how strongly the spring presses the cartridge into the magazine lips, and also has an effect on how easily the ammunition stack moves up the magazine. This seems to be independent of ammunition, and has
more to do with follower fit and smoothness of the inside of the magazine tube. It may be that this phenomenom is masking itself as a cartridge overall length problem.

--Dwight

Sieger

11-10-2003 01:23 AM

Dwight:

You have presented quite a detailed analysis here. Now let me challenge it while defending my position.

Given that a magazine is not bent, the spring in it is not too weak, the follower is not catching on the interior of the magazine and the magazine is in otherwise perfect condition, try the following simple test:

1)Load 8 rounds of round nose ball to 1.10 OAL.

2)Load 8 rounds of round nose ball to 1.175 OAL

3)Fill the magazine.

4)Work the action by hand until the magazine is empty, noting how smoothly or roughly the action works with each test length. Take careful note of how the first three rounds "feel" when feeding.

Try your visual check of the first three rounds, noting how they sit just a split mm or so before they engage the lips of the magazine. Are they parallel to the lips or are they canted downwardly?

The short loaded cartridges will cant slightly downwardly. This is the essence of the AOL problem, as the cartridges ride up the inside of the magazine by touching it with their bullet tips and cartridge rims. Please note that a Luger's magazine is shorter inside than the average cartridge, thus causing them to step-feed up the magazine.

I wish curing the jamming problem were as easy as relacing a worn magazine. If this were the case, there should be no jamming Lugers out there today, as a new excellent quality magazine costs less than $20.00.

Sieger

Dwight Gruber

11-10-2003 02:14 AM

<blockquote>quote:<hr />Originally posted by Sieger:
Try your visual check of the first three rounds, noting how they sit just a split mm or so before they engage the lips of the magazine. Are they parallel to the lips or are they canted downwardly?<hr /></blockquote>I have four magazines in fromt of me: an original Erfurt armorer's replacement, an original unmarked commercial, the no-name aftermarket noted above, and a Mec-Gar. With three rounds of Winchester in each magazine, they all exhibit the tilting phenomenon equally.

However, I notice this: the top cartridge tilts down until the the nose of the bullet contacts the front of the magazine at the point it is cut out. When the cartridge continues down the magazine, it resumes the orientation it had when it was in the feed lips--tilts back up. All four magazines exhibit this as well.

It works this way with S&B, as well--I don't have any Blazer to try right now.

--Dwight

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