I posted this in another thread:
I just measured the muzzle nut on my ASG gun.
It's an internally threaded tube 15mm long, outside dia. about 20mm before a straight knurl is applied.
A single 4mm wide groove is cut through the knurl,centrally along the length (the nut is symmetrical). The reduced dia. in the groove is about 17.5mm.
It looks like it's threaded M14 x 1mm pitch, RIGHT HAND - not left hand like most suppressors.
I'll confirm that over the next few days, and if it is that simple, I'll make a few.
EDIT: This information is incorrect. See my update post below
It's definitely NOT M14 x 1mm.
I made an M14 x 1 thread on the end of a piece of material, and the nut wouldn't fit.
Having measured the muzzle thread, It's actually more like M13.5 x 1 or M13.6 x 1.
I made an M13.5 x 1mm thread and the nut was a similar (slightly loose) fit.
I presume the silencer shown in that other thread is M14 x 1, which would bite on a 13.5mm thread, but it'd not be all that secure.
I don't yet have a small enough threading tool to make even an M14 x 1, so I can't currently make any of these nuts.
For corollary:
http://www.advanced-armament.com/product.aspx?pid=689
It appears M13.5 x 1 is a standard thread size for 9mm barrels, though the AGM MP40's is a right hand thread.
I can only assume the supplied nut's loose fit is a result of poor (i.e. cheap) manufacture, and that a proper M13.5 x 1 threaded nut would fit better and be more secure.
My previous post was incorrect.
The thread is indeed M14 x 1mm. But it's a loose M14 x 1.
I made one this afternoon:
Here it is next to the original:
I could do. Might be a bit costly on postage to the US for just one, though. Do you know of anyone else "local" that might want one and split the postage?
I was thinking £10 plus postage (not sure right now what that'd be to the US).
It's aluminium, which may be what the AGM original is made of - it's light enough to be. Would you want it painted black?
Or bright orange... 
I could do. Might be a bit costly on postage to the US for just one, though. Do you know of anyone else "local" that might want one and split the postage?
I was thinking £10 plus postage (not sure right now what that'd be to the US).
It's aluminium, which may be what the AGM original is made of - it's light enough to be. Would you want it painted black?Or bright orange...
i posted one of these to canada, cost about 4 quid
also i put it as a 2nd hand spare car part on customs form, after all its only a threaded nut 
and 2nd hand gifts arnt liable for import tax either
"Take that you rotton helping of strawberry flan!"
Joseph Porta to "strawberrys and cream", in the sven hassel book ,ogpu prison
Try looking for M14 x 1mm "thread protectors". They're mass produced, so they can make them cheaper, but you'll be lucky to find one to match the original.
WRT material: For that much, differences in material costs for plastic or metal are negligible. It's the time taken to make it that's the killer (that first one took about an hour). And plastic might take longer because the serrations might have to be cut individually, as I don't know if pressure-knurling would work like it does on metal.
Double-check which way the thread goes. I read one post which stated that the AGM MP40 thread is left hand (turn counterclockwise to do it up), however, mine (ASG, but I'm told it's the same as the AGM) has a right-hand thread.
As far as originals are concerned, I can't find the specs right now, but a lot of real steel German guns have left hand threaded muzzle attachments. And I've not seen an original listed for less than $30.
Thanks, Otto.
I'll look up the postage, and reply to your PM.
