Hudson AK47 Project

I thought id share my current project I’m working on.


I have an old Hudson AK47 and while it’s a great looking model (as with most Hudson’s) the firing performance leaves a lot to be desired (as with most Hudson’s)
So I thought………. I’d modify it.


I wanted to do several things to it which should overcome the firing problems

1: Install the auto sear (which is missing from all of the AK’s except the SE version)
2: Custom steel bolt
3: Make my own custom rounds to take the 7mm caps


First job, adding the auto sear.
The auto sear was added to the SE version to stop the hammer riding the bolt and should give the hammer strike more power on full auto. I got the auto sear and spring (many thanks shazhib) and installed the third pin for it to fit through.

This picture shows the auto sear pin



This picture shows the auto sear, spring, new hammer




This picture shows the hammer held buy the auto sear




While I was fitting the auto sear I also changed the hammer for the SE version which has the cut-out for the auto sear also it seems to be made from steel instead of zinc which should last a lot longer and is a straight swap with no modification needed.


Custom Steel bolt
As with all Hudson’s the zinc bolt material is a little on the soft side so keeping the upper bolt part I made a custom steel one which is more or less a straight copy of the original one. The one thing I had to do is make sure that the bolt would trip the auto sear at the right time to enable the hammer to fall as the bolt almost comes on contact with the breach face











I have done some provisional firing and it all seems to work well with the standard Hudson rounds (2x5mm caps) but I still need to do a lot of finishing off and try it with some Hudson rounds that are in good condition as I only have 4 and they are in poor condition.
I will decide whether to go with Hudson rounds or my own custom ones and keep you guys updated.
8ace

****Originally posted by cerwyn****





I can't wait to see more of this project.
I can only imagine the deluge of requests 8ace will receive from owners wanting a Hudson AK that works!
Could it be we'll see the first, and propbably only, video of a Hudson AK47 firing a magazine full here on our modelgun forum?
I hope so!
Outstanding work 8ace, I am deeply envious of your skills mate
Cerwyn

****Originally posted by 2sharp****




Mad machining skillz! And very neat project, it is always educating to see good, close-up pictures of any modelgun as i'm always curious on how they look etc.
Me too is very much looking forward to the progress of this project

****Originally posted by madmike****




I am very impressed by your new project. Great to read about it here. Please keep us updated.

****Originally posted by kickback****




8ace that looks absolutely brilliant mate!!,you have done yet another piece of great machinery,and if it works,something Hudson couldn't manage? a firing AK!.I cant wait to see the finished product keep us updated mate.
Great job

Cheers guys.

I should have some firing vids (if it works with new Hudson rounds) in the next couple of weeks

8ace

****Originally posted by madmike****




Yes, please show us those vids. I am very impressed. Can you still buy the new type Hudson AK rounds?

It would appear that the Hudson rounds are very difficult to get hold of

Looks like i will have to get solidworks out and design my own...... anybody got any thoughts on design

I was thinking along the MGC style (which seems to fire well) using a 7mm cap and possibly using MGC pistons.

I have some 12mm high tensile brass (manganese bronze) which should make great material as I don’t think my equipment is up to machining titanium but I’ll have a go.

8ace

****Originally posted by cerwyn****




By all accounts MGC's cartridge design works very, very well and spare internals are cheap and easy to get hold of.

A single 7mm cap is powerful enough to blowback against steel bolted models with strong springs so you shouldn't go far wrong there.

As it's a well proven system why not replicate the MGC style first to prove the gun itself will fire reliably? Once the firing action is sorted you could look at a modifying the cartridge design to get more sound maybe?

I'm really looking forwards to seeing your AK firing 'ace.

Cerwyn

I have taken a video of the internal workings (top cover removed) and dry fired first on semi auto then on full auto

https://s74.photobucket.com/albums/i273/88ace/?action=view&current=akmpeg.flv

****Originally posted by cerwyn****




Now that looks very promising doesn't it?

I hope you get some cartridges sorted soon mate, if feeding and extracting works as smooth as that action you're onto a sure winner

Cannot Wait!

Cerwyn

A quick project update.

I have managed to get some new AK rounds which I have had mixed success.
I'm pleased about the round damage which seems to be lower than the original setup (see pic below of a round used about 6-7 times)




The new rounds I got didn't come with the O-ring around the top piston which when fitted make a huge difference to the blowback power of the cartridge (see pic below)





I'm still not getting consistent firing on full auto and will be looking into the hammer/det pin/bolt configuration. One problem I have noticed is the hammer isn't made from steel as first thought but it's a chrome coated brass/bronze which is beginning to mark so I’ll have to fit a steel insert to stop this.

Watch this space

8ace

****Originally posted by cerwyn****




The amount of marking you're getting on the cartridge base looks about the same as I get when using steel models, MGCUKs STEN eg, or when using steel bolts in my Thompsons.

I find the Tumble Polisher useful here as it does smooth out any indents as well as polish the cartridges. It won't replace chips obviously but it does smooth out the rough edges.

The only modelgun I've got that doesn't mark cartridge bases is Marushin's MP40 which has an abs bolt.

I've never seen a Hudson AK47 cartridge... the piston you've photographed looks very different to any MGC or Marushin round I've seen previously.

How do you load this type please 8ace?

You couldn't do a Step by Step loading guide could you please?

Your AK project has all of us holding our breaths now. Just think mate, you might be the only owner of a working Hudson AK47 anywhere on the planet soon!

Cerwyn

Here is a pic of the Hudson AK round. There seems to be a few different types of rounds that Hudson made over the years (which I have little to no information on)




the type I have is a made from brass with 2x5mm caps (loaded facing each other) and when I have got things sorted out I’ll post a step by step loading guide.

8ace

****Originally posted by cerwyn****




Ahhhh so that's how they go together!

Thanks for the photo 'ace. There ought to be a decent amount of blowback from that set up shouldn't there? Those 5mm caps pack a fair punch.

Just thinking aloud now, but knowing how badly my model guns have performed in the past when I've put 2 caps in either Marushin or MGC cartridges, could it be that Hudson's cartridge design is flawed by having 2 caps?

I've had guns failing miserably to fire in Automatic because the bolt is thrown back so violently that it almost travels to fast and "trips" itself up. Constant jamming and misfeeds were instantly cured by fitting a single cap only.

Perhaps changing Hudson's design to use a single 7mm cap and an MGC piston might reduce blowback pressure thus slowing the rate the bolt travels enough to allow for slower and smoother action?

I'll look forwards to the Step by Step Guide 'ace!

Till later

Cerwyn

I have just finished the steel hammer insert which should stop any damage to the face




Just got to sort out the cartridges and it's done (fingers crossed)

8ace

Ah the plot thickens........

I have found that Hudson have changed the design of the AK rounds which now use 2x7mm caps in an aluminium round






I have tried some of these which do seem to eject better and have less damage on the rim but there is still a problem with feeding into the chamber (as Hudson is still getting) Also the new rounds require a new mag design as they don’t sit on top of each other in the old/real steel type.




Hudson website video
http://www.hudson-mfg.com/eng/default/new/AK47/AK47.wmv

8ace

now this is an interesting update .. Not sure why they have gone to alluminium instead of brass as the small amount of weight difference can`t be that much surely .

Thats the most I have see one AK in one uneditied film shoot !

he seems very careful with that bolt doesn`t he ...perhaps the rounds go off on their own if too heavy handed !

DOC

The last problem I have is the AKs feed and eject problem and I have a sneaky suspicion some of it could be due to weight. The 2x5mm brass rounds contain a lot of metal 20grams (which is heavy compared to other rounds), the aluminium ones weigh only 4g which puts less strain on the extractor claw and might explain.

A: Why the rounds don’t eject well (lot of twisting force needed to spin the round out of the ejection port)
B: A lot less damage to the rim made by the ejector (not knowing what grade of brass/aluminium Hudson use)

Both the brass and aluminium rounds seem to have enough power to force the bolt back so I don’t think its power related.

8ace

Like everybody else here, I'm following this project with great interest.

This might be a silly question but I'm curious...

Which force(s) actually throw out the spent cartridge?

Once the cartridge fires, there's obviously enough power to force the bolt back

The extractor claw has hold of the cartridge and pulls it out of the breech,

It's pulled back until it hits the ejector...

The ejector knocks the cartridge out of the extractor claw's grip but then what???

The spent cartridge will fly out of the ejection port with considerable force. Broken ornaments and dented walls are evidence of that!

Is it purely inertia that spits it out? After all these bolts hammer back and forth very quickly.

I noticed awhile back that weak magazine springs will stop clean ejection. New magazines always produce stronger ejection for me anyway.

Does the magazine spring have an influence or not? Does the next fresh cartridge pushing up from the mag' serve to push the spent cartridge out too?

What would happen if a slightly stronger magazine spring was fitted?

Cerwyn

Quote :

Which force(s) actually throw out the spent cartridge?

Once the cartridge fires, there's obviously enough power to force the bolt back

The extractor claw has hold of the cartridge and pulls it out of the breech,

It's pulled back until it hits the ejector...

The ejector knocks the cartridge out of the extractor claw's grip but then what???

(I think) that the ejector hits the back or the cartridge while the extractor is still holding on to it which should twist it towards the ejection port and lets go, hopefully spitting it out of the port.

Which brings me onto the whole chamber/breech/trunnion design of the AK which is so different to a real AK I’m surprised it feeds/extracts anything

I'd be interested to find out the weight of MGC and Marushin M16 rounds I would think that as they use 7mm caps the internal bore is bigger and the overall weight is less

8ace

I don't have scales that will accurately weigh anything that light.

I do have both MGC and Marushin 5.56mm cartridges though so if no-one can give you weights I'll send you these.

How does the ejection port of the model differ from the real AK then?

Cerwyn

Well I have finished the modifications which have filled some of the empty space which caused the rounds to miss the chamber entrance (as the marks in the 1st pic show)

1st mod: I fitted a modified feed ramp to guide the rounds in better which also has a slight angle on the right hand side to help the round eject.

2nd mod: I added some pins which guide the rounds into the chamber (with corresponding holes in the bolt assembly)

I have tried it with the brass 2x5mm rounds which work very well (but I ran out of 5mm caps), I still think the brass rounds are toooo heavy and I’m waiting for some 2x7mm aluminium rounds and a new mag to fully test it.

8ace

This pic is of the standard feed ramp/chamber opening


This pic is with my mods

8ace,yet again its a piece of art ,those mods look great ,keep us posted mate.
Hudsons test film of the AK firing looks great too,the new style carts must work a hell of a lot better than the old crappy ones ,they should make this type for all there models now ,fingers crossed

Kickback

Now there's a thought... Do you think Hudson might end up making much lighter catridges for all their models now?

Based on the amount of work and extensive mods carried out by 8ace on his AK so far, and the amount of work done on Hudson Thompsons and PPShs' to get them firing I doubt aluminium cartridges will be the answer to all the problems.

Wouldn't it be nice if it was so though