Nambu troubleshooting...

Zorba · 07-06-2014, 07:08 PM

John, you're excused.

My Nambu is a jam-O-matic, stovepipe special. For those familiar, here is a picture of the ramp/chamber mouth area - is that a chip at the bottom of the chamber mouth? Or is it supposed to look like that?

Overall image for viewer orientation:

All springs have been replaced, including in both mags (by G.T.).

DavidJayUden · 07-06-2014, 08:50 PM

I'm flying blind here so bear with me.
If it is stovepiping the fired case, might that suggest that the recoil is insufficient to bump the rim hard enough to eject it? Does it feed correctly using live ammo. (or dummies) and cycling the bolt by hand? Also is the ammo. of sufficient velocity go work the system? I understand that there aren't many choices of ammo out there.
Is the ejector long enough to hit the rim early enough?
Have you reverted back to the original mainspring? I'm also wondering if the replacement spring isn't too stiff.
Maybe give us a few more details on what it is, and is not, doing.
dju

nukem556 · 07-06-2014, 09:56 PM

There's no feed ramp on my Nambu, just a slight bevel at the 6o'clock position. Yours is much larger. Maybe someone Dremeled yours out, or they changed that profile over the years (mine's a 1937). I've shot mine with Mr.Nambu loads and some ammo remanufactured from .40 S&W brass and it functions fine with the original springs. I'd kinda doubt that making that bevel larger would cause your problems though.

Zorba · 07-06-2014, 11:05 PM

Ok, random factoids.

Mine's a '43. The only ammo I've used in it has been the "Mr. Nambu" loads, which is good ammo by all accounts. I fired about 20 rds, with 4 or 5 stovepipes. Manually cycling with snap caps is even worse - predictably enough. I'll take another squint at the extractor - however, I noticed today when playing with the gun and snap caps, that it wedged and stovepiped on the FIRST round - nothing in the chamber to start with. It did this at least twice.

How would I know if the *ejector* was right or wrong?

nukem556 · 07-06-2014, 11:38 PM

A "stovepipe" jam is usually referring to a FIRED case that isn't fully ejected and is caught between the bolt face and the chamber mouth facing up....hence a stove "pipe". What you're describing is a failure to feed and chamber. I'd suspect the feed lips on your magazine are sprung too wide allowing the round to sit too high to enter the chamber straight on.

tomaustin · 07-06-2014, 11:44 PM

if you haven't already found this site, google Nambu World, Teri Shaw's site......she has extensive connections and a wealth of knowledge.....I also have nambu interests and enjoy talking to her.....tom

Zorba · 07-06-2014, 11:54 PM

Quote:

Originally Posted by nukem556

A "stovepipe" jam is usually referring to a FIRED case that isn't fully ejected and is caught between the bolt face and the chamber mouth facing up....hence a stove "pipe". What you're describing is a failure to feed and chamber. I'd suspect the feed lips on your magazine are sprung too wide allowing the round to sit too high to enter the chamber straight on.

Yea, its doing both - but your feed lip suggestion sounds like gold - the round does indeed look very high at the top! I'll try some "monkeying"!

Zorba · 07-06-2014, 11:55 PM

Quote:

Originally Posted by tomaustin

if you haven't already found this site, google Nambu World, Teri Shaw's site......she has extensive connections and a wealth of knowledge.....I also have nambu interests and enjoy talking to her.....tom

An familiar with her site - I just wish it had a forum! Never thought to contact her directly though...

You guys here are great - if push comes to shove I'll take it to a 'smith, but Nukem's feed lip idea resonates with what I'd observed just today, and will try that first. I was wondering why the top round (snap cap) was so far up...

DavidJayUden · 07-07-2014, 11:47 AM

Maybe try to beg/borrow/steal a loaner magazine to see it it works before you start bending? I'd loan you one but have no access to the Nambu's for a few weeks.
dju

Zorba · 07-07-2014, 01:41 PM

Next best thing, I have 2 mags. To be honest, yesterday's test was only with one of them. If I don't get anywhere, I'll take the whole mess to a gunsmith - we have an old timer here who shouldn't have too much problem with it...

John Sabato · 07-07-2014, 02:16 PM

Excused?

...and I was going to suggest that your first step in curing the problem was to not load the Nambu!

Zorba · 07-07-2014, 02:44 PM

Seeing as I know your love for all things Nambu, I figured you'd rather stay outta the room! After all, it might go off!

Still, since you're here; how about a Nambu patch!

John Sabato · 07-08-2014, 10:10 AM

It is amazing that you have to have a C&R or FFL to mail these "guns" to each other... Don't they have to WORK in order to be considered a firearm?

Quote:

Originally Posted by zormpas

... how about a Nambu patch!

Would that be a Nambu with a band-aid on it?

Zorba · 07-08-2014, 11:06 AM

Quote:

Originally Posted by John Sabato

It is amazing that you have to have a C&R or FFL to mail these "guns" to each other... Don't they have to WORK in order to be considered a firearm?

Whaddaya mean? My Nambu works just fine! Those papers on my desk aren't going anywhere!

Quote:

Would that be a Nambu with a band-aid on it?

FUN-NY GUY!

Zorba · 07-09-2014, 05:50 PM

Anybody gotsa couple of pix of the top of a working nambu mag - with and without loaded rounds? It would be very helpful for comparisons...

nukem556 · 07-09-2014, 08:53 PM

Here's a couple quick ones.....Oh and we need to try to get John to quit hatin' on the Nambu! Somebody write a post about a Glisenti !

sheepherder · 07-09-2014, 11:30 PM

Quote:

Originally Posted by nukem556

Somebody write a post about a Glisenti !

Quote:

Originally Posted by Edward Tinker

I have had at least one Glisenti and have seen a couple more, but caliber is whacky and the gun is expensive just because...

Ed Tinker seems to have intimate knowledge of the Glisenti...I'd be interested in reading his in-depth review of this iconic WW II handgun...

Zorba · 07-10-2014, 12:44 PM

Quote:

Originally Posted by nukem556

Here's a couple quick ones.....Oh and we need to try to get John to quit hatin' on the Nambu! Somebody write a post about a Glisenti !

Thanx for the pix, Nuke! That should be enough to get me started!

As for John's non-love of the Nambu, it doesn't take a degree in psychology to figure that one out...

John Sabato · 07-10-2014, 12:58 PM

okay, enough fun...

Here is a serious suggestion. Look into the Airsoft line of Nambu's as the photos appear that the magazines may be able to be modified to handle real ammo... At least the body shown in the example photo looks pretty close to the real thing... it would be a real "project"... but it could work. (ignore the title of the link... it really does show an airsoft nambu mag)

http://www.airsoftatlanta.com/Maruze...ck-p/67054.htm

Zorba · 07-10-2014, 04:19 PM

Isn't *that* something!

07-06-2014, 07:08 PM	#1
Zorba User Join Date: Feb 2013 Location: Merritt Island, Fl Posts: 952 Thanks: 777 Thanked 528 Times in 290 Posts	Nambu troubleshooting... John, you're excused. My Nambu is a jam-O-matic, stovepipe special. For those familiar, here is a picture of the ramp/chamber mouth area - is that a chip at the bottom of the chamber mouth? Or is it supposed to look like that? Overall image for viewer orientation: All springs have been replaced, including in both mags (by G.T.).

07-07-2014, 02:16 PM	#11
John Sabato Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: The Capital of the Free World Posts: 10,156 Thanks: 3,003 Thanked 2,308 Times in 1,098 Posts	Excused? ...and I was going to suggest that your first step in curing the problem was to not load the Nambu! __________________ regards, -John S "...We hold these truths to be self-evident that ALL men are created EQUAL *and are endowed by their Creator* with certain UNALIENABLE* rights, and among these are life, LIBERTY, and the pursuit of happiness..."*

07-09-2014, 08:53 PM	#16
nukem556 User Join Date: Jul 2010 Location: Irmo, SC Posts: 625 Thanks: 35 Thanked 168 Times in 107 Posts	Here's a couple quick ones.....Oh and we need to try to get John to quit hatin' on the Nambu! Somebody write a post about a Glisenti ! Attached Thumbnails

07-10-2014, 12:58 PM	#19
John Sabato Lifer Lifetime Forum Patron Join Date: Jun 2002 Location: The Capital of the Free World Posts: 10,156 Thanks: 3,003 Thanked 2,308 Times in 1,098 Posts	okay, enough fun... Here is a serious suggestion. Look into the Airsoft line of Nambu's as the photos appear that the magazines may be able to be modified to handle real ammo... At least the body shown in the example photo looks pretty close to the real thing... it would be a real "project"... but it could work. (ignore the title of the link... it really does show an airsoft nambu mag) http://www.airsoftatlanta.com/Maruze...ck-p/67054.htm __________________ regards, -John S "...We hold these truths to be self-evident that ALL men are created EQUAL *and are endowed by their Creator* with certain UNALIENABLE* rights, and among these are life, LIBERTY, and the pursuit of happiness..."*

07-06-2014, 08:50 PM	#2
DavidJayUden Patron LugerForum Patron Join Date: Nov 2008 Posts: 4,047 Thanks: 578 Thanked 1,414 Times in 887 Posts	I'm flying blind here so bear with me. If it is stovepiping the fired case, might that suggest that the recoil is insufficient to bump the rim hard enough to eject it? Does it feed correctly using live ammo. (or dummies) and cycling the bolt by hand? Also is the ammo. of sufficient velocity go work the system? I understand that there aren't many choices of ammo out there. Is the ejector long enough to hit the rim early enough? Have you reverted back to the original mainspring? I'm also wondering if the replacement spring isn't too stiff. Maybe give us a few more details on what it is, and is not, doing. dju

07-06-2014, 09:56 PM	#3
nukem556 User Join Date: Jul 2010 Location: Irmo, SC Posts: 625 Thanks: 35 Thanked 168 Times in 107 Posts	There's no feed ramp on my Nambu, just a slight bevel at the 6o'clock position. Yours is much larger. Maybe someone Dremeled yours out, or they changed that profile over the years (mine's a 1937). I've shot mine with Mr.Nambu loads and some ammo remanufactured from .40 S&W brass and it functions fine with the original springs. I'd kinda doubt that making that bevel larger would cause your problems though.

07-06-2014, 11:05 PM	#4
Zorba User Join Date: Feb 2013 Location: Merritt Island, Fl Posts: 952 Thanks: 777 Thanked 528 Times in 290 Posts	Ok, random factoids. Mine's a '43. The only ammo I've used in it has been the "Mr. Nambu" loads, which is good ammo by all accounts. I fired about 20 rds, with 4 or 5 stovepipes. Manually cycling with snap caps is even worse - predictably enough. I'll take another squint at the extractor - however, I noticed today when playing with the gun and snap caps, that it wedged and stovepiped on the FIRST round - nothing in the chamber to start with. It did this at least twice. How would I know if the ejector was right or wrong?

07-06-2014, 11:38 PM	#5
nukem556 User Join Date: Jul 2010 Location: Irmo, SC Posts: 625 Thanks: 35 Thanked 168 Times in 107 Posts	A "stovepipe" jam is usually referring to a FIRED case that isn't fully ejected and is caught between the bolt face and the chamber mouth facing up....hence a stove "pipe". What you're describing is a failure to feed and chamber. I'd suspect the feed lips on your magazine are sprung too wide allowing the round to sit too high to enter the chamber straight on.

07-06-2014, 11:44 PM	#6
tomaustin Lifer X5 Lifetime Forum Patron Join Date: Sep 2008 Location: texas Posts: 708 Thanks: 87 Thanked 522 Times in 201 Posts	if you haven't already found this site, google Nambu World, Teri Shaw's site......she has extensive connections and a wealth of knowledge.....I also have nambu interests and enjoy talking to her.....tom

07-07-2014, 11:47 AM	#9
DavidJayUden Patron LugerForum Patron Join Date: Nov 2008 Posts: 4,047 Thanks: 578 Thanked 1,414 Times in 887 Posts	Maybe try to beg/borrow/steal a loaner magazine to see it it works before you start bending? I'd loan you one but have no access to the Nambu's for a few weeks. dju

07-07-2014, 01:41 PM	#10
Zorba User Join Date: Feb 2013 Location: Merritt Island, Fl Posts: 952 Thanks: 777 Thanked 528 Times in 290 Posts	Next best thing, I have 2 mags. To be honest, yesterday's test was only with one of them. If I don't get anywhere, I'll take the whole mess to a gunsmith - we have an old timer here who shouldn't have too much problem with it...

07-07-2014, 02:44 PM	#12
Zorba User Join Date: Feb 2013 Location: Merritt Island, Fl Posts: 952 Thanks: 777 Thanked 528 Times in 290 Posts	Seeing as I know your love for all things Nambu, I figured you'd rather stay outta the room! After all, it might go off! Still, since you're here; how about a Nambu patch!

07-09-2014, 05:50 PM	#15
Zorba User Join Date: Feb 2013 Location: Merritt Island, Fl Posts: 952 Thanks: 777 Thanked 528 Times in 290 Posts	Anybody gotsa couple of pix of the top of a working nambu mag - with and without loaded rounds? It would be very helpful for comparisons...

07-10-2014, 04:19 PM	#20
Zorba User Join Date: Feb 2013 Location: Merritt Island, Fl Posts: 952 Thanks: 777 Thanked 528 Times in 290 Posts	Isn't that something!