MP40 Misfeed Problem

Post by Tancor

Hi all,

I finally got the last few pieces together of my MP40. I put a unloaded cartridge in the clip, loaded the clip into the gun, pulled the cocking lever, and pulled the trigger. Bolt flew closed and WHAM. Cartridge hit the bottom of the barrel, and did not feed into the firing pin area. I tried it a couple of times, and had the same results each time. I don't *think* I have it together wrong, I don't seem to have any spare parts and I checked the manual again. The clip is going all the way in - it's a bit tight, but it does go into the stop.

Here's a blow of of the portion where the cartridge is hitting...



If anyone has seen this in the past, any ideas on how to fix it? I notice the barrel, when inserted, sits a little forward of the metal portion it slides into, ie the rear of the barrel is not flush with the rear of the metal tube it sits in.

Any suggestions would be most appreciated!

-Tony

Post by Mark

Hi Tony,

The problem you are describing is a common one..The magazine on the Marushin doesn't fit very tightly into the magazine housing and allows fore and aft movement of the magazine. This movement changes the cartridge feed angle up and down..

Try pushing the magazine slightly forward when you try to fire it. This will change the feed angle and possibly stop th problem.

Can you see why I made my chamber out of steel?

Post by Tancor

Hi Mark,

what's funny is the magazine is super tight in the housing, I have to give it a good push to get it in and pull to get it out when pressing the magazine release, it must have some forward / backward play that I didn't notice. I'll check it again.

I was actually going to post on that other message you had responded to (I wasn't sure if my problem was similar or not) - but if you do make some more, I'd love to buy one... also if you know where to get some of the metal housing parts...

-Tony

Post by Mark

Yes, when I first received my factory assembled Marushin MP40, it had a vey tight magazine housing they wear fairly fast so it didn't take long to remove the high spots off of the magazine housing.

The fore/aft movement has always been present though..

I only have one steel chamber at the moment and it is spoken for by a person in Ireland and I have recently sold one to a person in Greece...

But, I can make one at any time it takes a day or so of work (if I am not distracted by the forum or my job search) to make one.

Metal housing parts?

Post by evil_kot

I had same problem.

I’ve seen on one of the forums then:

“On the mp40 marushin jamming, its a real problem with the mag not loading the shells at the proper angle, try opening the "fwd lip" of the mag to allow the shells to sit on the follower at a better up angle, sometimes they sit to flat and will dig into the feed ramp in the barrel.”

(http://www.machinegunbooks.com/cgibin/ikonboard/printpage.cgi?forum=5&topic=95)

I bent the mag’s “lips” (forward part) by pliers A LITTLE. That worked for me. The trick works not immediately, you have to experiment.

Post by Mark

I think that I might have written that post on Machinegunbooks.com (I didn't go look but I have been a member there for a long time there) Anyways, the fact that the magazine rocks back and forth in the housing makes the proper feed angle change.

when the feed angle changes too much the cartridges hit the bottom of the barrel/chamber.

Sometimes the magazine itself can be the problem but that is rare.

Post by Tancor

Well, now with a *little* bit of bending on the front portion of the mag lips (I assume you mean the ears that keep the cartridges in the mag), I got it to work on 2 rounds manually cycling, but after that it now jams at the top... I'd almost rather get it to jam at the bottom and either file down the feed ramp or add a piece of plastic or something in to help feed the cartridge in correctly...

-Tony

Post by Mark

Woh, be careful with the feedlips on the magazine as the are hard to re-adjust if they are off on the feed angle.

In fact, adjusting the magazine to correct the feed angle would be my last method I would try.

I have an actual MP40 magazine that works flawlessly in my Marushin and my MGC.

I have never touched the feedlips on my MP40 magazines its been 90% the magazine to housing fit that has been the problem..

Post by Tancor

Well, good news and interesting news....

It seems that it wasn't the ears, nor the way the magazine sits - at least in my case for the moment (I say that as this will probably change with use as the chamber the clip goes into gets worn down similar to what you've talked about in the past mark).

It appears to be functional at this time, but I don't want to say what I did until I have done more tests on it to confirm my thoughts (ie: I don't want to sound like an idiot ) - also I want to try to make sure I didn't just make a bandaid for my problem rather than have fixed it.

But, none the less, if you do make another one of the steel portions to replace the plastic one - after you've met your existing obligations mark - consider it sold!

In terms of metal parts - I would like to get a lightweight metal barrel, and the receiver housing (?correct part term?), and the two plastic side pieces that screw on. Not that it'd do anything but adjust asthetics, I'd think it would look fairly neat, and since it isn't firing real bullets, it'd probably not have to be as heavyweight metal as the realsteel - I don't know, it's just a thought .

-Tony

Post by Mark

Hi Tony,

Ok, When I get to building some more chambers which type do you want carbon steel or stainless steel?

As for the barrel, I haven't looked into that part yet..Prehaps I might consider making one later.

Now, due to federal law, I cannot make an aluminium or any metal replacement receiver for the Marushin as it would be considered as manufacturing a "machinegun" toy or no....

So, certain parts are out of the question unfortunately....

The two plastic side pieces that screw on are the forearm pieces they are in fact plastic on the real MP40 however, they where Bakelite and they where originally cast in one piece.

If you want added weight to simulate the real MP40 you could get stick on lead weel weights and put them in the inside of the two piece forearm pieces they will add weight and remain invisible too.

Post by evil_kot

Yes, adjusting lips requires some tuning, as I told before. You give it a little tension and try manually clicking it. It took about 2 hours for me to fine tune these.
Mark, I thought you told before that the tension of a real magazine’s spring is too high for models. Now you saying it perfectly fits. Btw, - for Tancor – real magazines are relatively cheap- like $40, and they add some weight and style. So, Mark, do you actually recommending to get a real mag?

And, I’ve seen a Canadian site that sells real guns – they have every single piece of real MP40 in stock (cheap). I have not tried them yet, but for starters, I’m going to order Front Sight Cover and Resting Bar from them. I’m really sick of that pathetic Marushin’s plastic Front Sight Cover surrounded by metal. Mark, what do you think what else worth to buy from them? I’m thinking of Recoil Rube Assembly – that should add weight and reduce the rate of fire.

http://www.marstar.ca/mp38-40.htm

Thanks!

Post by Mark

Yes, the modelguns are usually very sensitive to spring pressures but for some reason, the real MP40 magazines work with out too many problems.

The magazines fit and seem to work ok but, that is just my paticular modelgun.. They might not work for you...They shouldn't add weight though, as Marushin copied the original magazine fairly faithfully with the exception of the construction method and the spring pressures.

Due to federal laws, you cannot order any parts for any gun from Canada,Mexico or Europe with out a federal form 6 that has to be approved before Marstar will sell them to you...Now, accessories like slings,magazine loaders, and pouches can be imported from them with out any problems.

Your marushin cannot take the spring pressure that the real recoil spring has..

Post by evil_kot

I did not mean the spring of the real thing, but these spring's holders -three cones, see #65 http://www.marstar.ca/images/Automatics/MP38u40/mp40.jpg And, for the BATF - Not really: Under Arms Export Control Act regulations in 27 CFR 47.41(c), a permit is not required for the importation of: Minor components and parts of Category I(a) firearms, except barrels, cylinders, receivers (frames) or complete breech mechanisms, when the total value does not exceed $100 wholesale in any single transaction. So we can order some stuff. And, WTH, we can always get that permission for the firearms. It's free, and we live in America, for the hell's sake!

Post by Mark

The problem here is that the MP40 is of course, a machinegun and is not a catagory 1 firearm under Minor components and parts of Category I(a) firearms

As the parts are machinegun parts they are in the perview of the BATFE who controls the importation of these parts..

Besides, I cannot have any parts for a real MP40 in Washington state as machinegun parts are a bad thing here...

You might want to research the importation rules on machinegun parts again..Perhaps, maybe the rules have changed since I checked the last time.

Post by Tancor

Hi Mark,

Which of the two types of steel would hold up better in this type of usage considering the corrosive nature of the caps and the regular washings and such?

In terms of the barrel, I was thinking of that part mostly from a balance perspective, the gun seems really grip heavy since that is where the bulk of the metal is - now this may be similar to the real thing, but it just feels off.... plus I'm not sure how to paint existing barrel effectively, and I'm afraid if I sand down the seam lines, I wouldn't get a good looking coat of paint on it.

I wasn't sure where the limit was on replacement parts - no big deal, wasn't sure where the line is on BATF rules and such especially with machine guns as I never really looked into going beyond pistols and rifles.

Good idea on the weights, it would add more weight toward the front of the gun, I may look into it later on.

Evil_kot - I'll have to look into the mags, thanks for the suggestion!

-Tony

Post by Mark

Hi Tony,

Either chamber would be ok if they where cleaned and oiled freqently. But, of course, the stainless steel chamber would be better as the carbon steel chambers seem to rust fairly fast even with care.

The rust isn't too bad and is really cosmetic in nature and since the chamber is very thick the only problem might be the rust acting as a frictional point.

The stainless chamber will eventually rust too but it takes some time between cleaning to make this happen..personally, I preferer the stainless.

The barrel might be a good idea but, there are some problems in making them and the Marushin barrel has a built in tab for the location of the front sight housing. On the original MP40 the front sight housing was held on the barrel by soldering and that's not possible with the zinc front sight housing/aluminum barrel.

The chamber piece adds a few ounces to the front of the MP so that kind of works to an advantage.

As for sanding the seam, try using fine wet/dry sand paper and when the seam is sufficiently sanded to your liking, take a piece of cloth and perhaps some polishing compound and polish the area you shouldn't have to use paint..

Hi
I am very new to the MP40 PFC gun world and am just getting acquainted with the ins and outs!
I recently purchased a MP40 which only fired the very last round in the mag. Every other round jammed as they were either too high, low or to one side. But the last was always perfect.
John at Plugfirecapguns UK in Cambs from whom I purchased several guns, talked to me on the phone and mentioned mag lip alterations but as a total newbie I wasnt too keen to making changes myself. I went to see John today and he sorted it all in a very professional manner.
A bit of mag lip tweaking and an adjustment to mag stability which I think he has posted elsewhere on this forum gave me a very slick and smooth gun!
I have to highly recommend his products and services at http://www.plugfirecapgunsuk.com/

One thing I did find that may be of interest to others is a really cheap ultrasonic cleaner from ALDI. It cost just 19.95 at the ALDI near me in Syston, Leics. That seems 'dirt' cheap?!

The reason why I have the MP40s is because I am producing and directing a no-budget(!) WW2 "chiller" film set in an old Napoleonic fort in Dover which involves 4 German soldiers (hence MP40s and a P38) spending the night there in 1944 but things dont go too well for them during their brief stay.

Thanks again John!
Doug

Aldi have in the past done Ultra sonic cleaners for less than that , I think even 9.99 once,

is your film a no budget version of "The Bunker " 2001 with Jayson Flemyng (the cockney chappie from lock stock and quite a few others )

Hope to god its better than that as that was awful

DOC

Hello slugster and welcome to the forum

Marushin's MP40 is a very good bit of kit and when set up properly they'll fire reliably and consistently. Many a collection has started with an MP40, mine included

It's good to hear positive reports about good after sales service from dealers too. Thanks for that.

Ultrasonic cleaners are marvellous things to have. They make cartridge and chamber cleaning much easier and achieve a good clean finish. There'sa cleaning sollution called "Sea Clean" marketed by "James", you'll find it on e-Bay, that's been mentined here before. I've recently started using it and found it to be excellent.

Good luck with your filming. Let us know when the film's ready to view please

DOC wrote:

Aldi have in the past done Ultra sonic cleaners for less than that , I think even 9.99 once,

is your film a no budget version of "The Bunker " 2001 with Jayson Flemyng (the cockney chappie from lock stock and quite a few others )

Hope to god its better than that as that was awful

DOC

Hi
Yes you are right about that 9.99 - and I just missed that offer It is very good though and I think I will take a look at the Sea Clean solution that Cerwyn mentions.
Lol@Bunker
Hopefully a much better script! More on the lines of The Keep (1983) in terms of genre. Am also extremely lucky in that a neighbour was in Tomb Raider 2 and a friend was a stuntman in Dark Knight so got some professional input there - albeit paid for with just bacon butties and non-stop tea!

2 soldiers have the PFC Marushin MP40s, officer has PFC P38 and another has a K98.
When the main film website is lock n loaded I will post so everyone can get a better idea of the project. The film itself will most likely be posted on vimeo when complete.
Cheers
Doug

Keeping fingers crossed for your film, and for modelguns to behave correctly :-)

Good luck with your project

It'll be great to see PFC Modelguns used in the Movies again. Forum member trevinator from the USA has used PFC models for firing footage in his movies (and very effectively too) not forgetting member Pitfighter of course who has featured PFC Modelguns in his Films too

Hi All

Im very new to this and have the same problem,I dont know if i can do it myself but would like to if some one could give me a few instructions and maybe a few photos if possible.

I received this on friday but it had been fired but he had not cleaned the mp40 or the cartridges but out of 70 carts I lost 3.
I stripped it down today and gave it a good clean and oil,he had it for years and had never oiled it???????????????

If some one could help me I would be very grateful.

also where is a good and reasoable place to buy spares

Hi

Also which are the best and loadest caps to buy

Hello Stuart, welcome to the forum, it's a pleasure to have you with us

Which MP40 modelgun do you have please Is it an MGC68 steel and Zinc, Marushin ABS or possibly an older zinc alloy Marushin or Nakata model

Broadly speaking, missfeeds can be caused by missalignment of the magazine. The most common cause of problems is the way the magazin is held during firing. The correct way to hold the MP40 is to hold the foregrip behind the magazine, but this rarely happens in reality.
Next best way is to grip the magazine well firmly.
The mistake most make is to hold the magazine too low down its' length. Doing his causes the magazine to rock back and forth in the well, altering the angle the cartridges sit in the gun itself.
Push the bottom of the mag forwards and the cartridges point nose up, pull it back and they cartridges end up nose down.

It's not uncommon for magazines to become rather loose in the well too. This just accentuates the rocking of the mag if it isn't held properly.

Old magazines may have been dropped a few times or knocked about which might have bent the feed lips out of alignment. This presents the loaded cartridges at the wrong angle for smooth feeding causing missfeeds.

If you let us know which model you have, it'll be easier to give you more detailed help.

Caps, you'll have a choice of three types. All the PFC MP40s use 7mm caps anyway so

• MG Caps good sound, smoke effect, good blowback power
  
• Marushin caps good sound, sparks effect, slightly less power (not much less though)
  
• RealFlame caps good sound, sparks effect, similar power to Marushin. (No flame though as the name suggests )
  

The loudest caps will depend on model type and cartridge used. Bear in mind no cap will be as loud as a Blank round, but loud enough to make you grin indoors.
Marushin caps used in good condition Marushin cartridges will work best and loudest, in my opinion, because Marushin's cartridge firing pin punches a neat hole in the cap allowing more sound to pass out of the cartridge.
Older cartridges loose the sharp tip of the pin so although they'll ignite the cap they don't punch the hole through. Often too, older cartridges have worn or "blown" threads losing gas pressure during firing reducing sound and blowback too

Spare parts and accessories' availability depends on model type again. Let us know what you've got and we'll point you in the right direction