Denix Coachgun to PFC conversion

Hi all,

I've just completed my project to convert Denix's Coachgun to fire PFC caps. It's relatively straightforward and was achieved with ordinary DIY tools - although a couple of the tasks were made easier by using my small lathe and miller.

Firstly a word about the Denix itself, the castings and construction are of reasonable quality and the actions are crisp. There is a little slop in the break action when the barrels are closed but its fairly minor quibble. Overall it feels good and solid.

Given that the Denix has functional external hammers, working break action and hollow barrels this meant a lot of the groundwork is in place - thanks Denix!

I have an MGC 31-RS2 and intended to use the shells from that for this project, being fully prepared to have to bore out the breach area for them to fit. As it turns out the shells drop into the barrels no problem, in fact they go quite far in.

Using the RS2's detonator area as a template I made up two aluminium detonator chambers out of 20mm dia bar stock and the det rings out of 9.5mm solid brass bar. I bored out the brass to match the RS2's ring and profiled the rim to give a smaller surface area for more impact on the cap. The brass was then inserted in the aluminium and secured with a grub screw.
I then positioned these chambers in the denix barrels so that with a cap in the shell the bottom of the shell is flush with the face of the barrel. These were then secured in place with screws.

I then turned to the breech and drilled holes (3mm) through the fake percussion nipples out to the breech face and then enlarged the holes in the breech face to allow the nuts to recess into it. I then inserted 3mm cap head bolts cut to length and secured them with dome head nuts.
So now when you cock the hammers and fire, the bolt/nut is driven forward onto the back face of the shell and detonating the cap on the brass ring.
The way the breech closes means that even with loaded shells and the hammers forward the nuts just get pushed back slightly on closing.

On initial dry fire testing I found the shells got stuck sometimes so created an extractor out of some ally rod and thin strip. This was where the lathe and miller came in handy to drill the hole and make the slot.

I found the standard 5mm (Maru or MGC) caps didn't seem to work very well, maybe due to the detonator rings and/or insufficient striking force from the Denix hammers - probably more the latter. So given the 7mm caps are more easily deformed due to them being more 'open' I milled out the top of one of the shells to accept a 7mm cap on one side of the 'X' (you can still put a 5mm on the other side). Again I used a 7mm flat ended milling bit on my miller to do this.

The Marushin 7mm caps fire far more consistently and produce plenty of sparks, smoke & noise.

Detonators and position on barrels:

Detonators internal:

Breech area:


Breech closing:

Shell extractor:


SAS

Excellent job! Well done.''

I'll look forward to seeing your photos!
Kiwigunner

Sounds very interesting, I'll look forward to seeing the photos.

Pics up, i'll try to get one of the 5 to 7mm shell mods and it firing.

SAS

Well done Sidewinder, this is a neat and tidy conversion and certainly makes a Denix Coachgun a more attractive modelgun:!:

Just one concern though, and something you might want to check, should the barrels have some some form of permanent blocking in them to keep them legal
I might be comletely wrong but I'd double check to avoid any unwanted problems with the law. Anyone with an ounce of common sense wouldn't attempt to fire a live shotgun shell in a Zinc barrel BUT, could your hammer / firing pin be seen by the Police as a "possible" means of striking the primer of a live shotgun cartridge
A permanent partial blockage of the barrel might be essential to prevent live firing.

As it stands now you can't actually chamber a real shotgun shell*, you would need to enlarge the inside back ends of the barrels to accept the rim.
Also i'm not sure if the hammer springs are strong enough to fire a real primer.

This was never a real gun so is not covered by deac laws, nor is it a blank firer (you couldn't chamber blanks for the reason above) so it's just a toy as 'real' PFC modelguns are.

SAS

* according to my research on shell dimensions, I don't have an inert one to try.

Lovely project!

Great to see this model enhanced for more fun :-)

I know this is an OLLLLLLLLLLLLD thread, but I am thinking about getting one of these coach guns to modify to use the new 7mm multi-cap cartridges. Seems like it would be a pretty straight forward modification that could produce a relatively inexpensive cap-firing FULL METAL model gun. Seems like it is possible that the only mod would be to create the firing pins.

I know with the open barrels that this could create some concerns potentially.....

Any thoughts?

buy 12g brass snap caps then turn to fit, the drill out to fit pfc carts, easy