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

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!

Tom,

Ammo is the answer.

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.

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.

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

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.

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

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

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?)

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by unspellable:
<strong>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.
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">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

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

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

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.

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...

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Johnny C. Kitchens:
<strong>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...</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">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

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Dwight Gruber:
<strong>
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</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">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

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by unspellable:
<strong>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.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">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

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

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Dwight Gruber:
<strong>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</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">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