So, I finally got to bring home my MP-40 submachinegun (purchased last year) today.

Doing my first field strip & discovered that it doesn't have the firing pin assembly
shown in most of the web references; rather, it appears to have this--

  http://www.ima-usa.com/original-fbp-fixed-firing-pin-bolt-and-recoil-assembly-german-mp-40-smg-interchangeable.html#tab-reviews

  (see also HERE)

- I'm probably OK with this, as it's just a "tube gun" anyway, and seems to function just
fine (with hot ammo & proper lubrication).

Just wondering what the consensus on the board was, on this matter... better / worse than the
"classic" MP-40 design?

Still intend to get a parts kit for this gun, still accumulating a few magazines (both of these
items being quite $$ expensive just in and of themselves)

Thanks,

SD

Since it is a tube gun, Why bother???  
I took the orig bolt/FP out of my tube gun and replaced it with one of those.  No reason to screw up an original!  
Sarge

From a shooting perspective, the bolt assembly you have is an improvement, since the long and somewhat fragile firing pin is no longer part of the system.  If your gun was an original WW II firearm, having the wrong bolt assy would be a problem, but since it's a tube gun I would call it a plus.

Personally, I would not waste money on a parts set for the MP-40, since short of throwing it out of your car window at 65 MPH, you won't break anything on it other than possibly an extractor.  Buy one of those and a bunch of magazines and go have fun.

I hope the price reflected an FBP bolt/spring assembly....

Make sure the FBP recoil assembly has MP-40 springs in it however. The FBP springs are a bit too stiff for an MP-40, and there is a real chance of having the gun runaway if they aren't changed

Thanks for the feedback thus far, I'll throw out a few more comments on my gun...

- Mechanically, the simpler FBP bolt does seem like it would be more reliable (like an M1A1 Thompson, UZI, or Sterling).

- I know that at least in the case of the Thompson, people say that the original firing pin design (e.g., on the
M1928 or M1) makes sure it will only fire when the bolt is closed (so lower chance of an out-of-battery
ignition).  But in the case of the MP-40 firing pin, doesn't seem like there's any such advantage... not quite sure
why the Germans did it that way.  And as is well-known, the other major weak point in the design is the
single-feed magazine.

- But even so, the original gun is almost amazing in its simplicity; there's not even a safe/semi/auto selector switch, the
trigger is just directly connected to the sear with no interruptions.

- About getting a parts kit:  for one thing, my folding stock is a bit wobbly.  Although this seems to be the case for most of these
guns (just from what I can tell), I thought I might be able to trade out for one that locked up tighter.

- Also, while I don't anticipate running this gun particularly hard, I thought that having an extra barrel on-hand might be handy
down the road.

Thanks again for everyone's input.

SD

OP,
     I replaced the original Erma bolt & recoil assembly in the all matching '41 ERMA MP40 I had with an FBP assembly from IMA. It was a simple drop-in replacement that worked fine with no issues firing all the 9MM ammo types I tried from low power thru the Hirt +P+ L7A1 open-bolt SMG only ammo. There is an MP40 gunsmith out there who specializes in taking the wobble out of the original MP38/MP40 stocks but I never learned his name. Ask for information about it on the other MG boards. I purchased a '43 Erma MP40 stock assembly he had rebuilt back to "zero" play and it made it easy to fire the MP40 VERY accurately. HTH

I NEED to find this guy when my Form 4 comes back. My MP40 stock has quite a bit of wobble in it and when you extend it, it basically falls free when the button is pressed. Would very much like to have it fixed.

Good info on the FBP bolt! I was wondering this as well. Will probably pick one up.