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building a free pistol?

Posted: Tue Jan 03, 2012 12:29 am
by lxvnrsw
Hey guys,

This probably seems kinda crazy but I have access to a full machine shop and as an engineer I think my next project will be to try to build a free pistol of my own design. Looking at the ISSF rule book it really seems like free pistols really are "free" when it comes to their design so long as they have iron sights and a grip that does not contact any point behind the wrist. But I've heard there's some "box" that the pistols need to fit into, anyone know the dimensions that this box is?

Also, if anyone here would be so kind to provide me with any technical specs regarding their own free pistol's barrel length, sight radius, barrel diameter, and grip angle that would be greatly appreciated, seeing as the more data I have the better I'll be off in this project (although I've already got a solenoid powered firing mechanism mocked up and the plans for a small martini and/or falling block action all worked out for me to begin fabricating).

Thanks guys!

Posted: Tue Jan 03, 2012 1:04 am
by j-team
Crazy, maybe...

I build this one 3 years ago. It's rather crude on some areas with a minature bolt action and mechanical trigger that can't really be adjusted below 100 grams.

It started as a joke to be honest. I spent more time mulling over how to do it than actually making it.

Most importantly, I really enjoy shootng it and with the amount of training I do these days, I don't think I could shoot any better that with a "bought one"!

The other thing I like telling people is that I only spent $35 on it. That was for the bluing and annodising. I had the bit of barrel and sights lying around and the materials for the parts I made came from off cuts (I'm a toolmaker).

My serial number is FP-001

Re: building a free pistol?

Posted: Tue Jan 03, 2012 1:15 am
by Spencer
lxvnrsw wrote:... But I've heard there's some "box" that the pistols need to fit into, anyone know the dimensions that this box is?...
Boxes are for 10m and 25m only

How much FP 002 can cost

Posted: Tue Jan 03, 2012 6:29 am
by Russ
It is nice looking FP j-team. How much FP- 002 can cost for me? ;)

Posted: Tue Jan 03, 2012 10:20 am
by Bob LeDoux
J-Team: Looks like you copied the Pardini K50.

The real issue with a free pistol is the trigger assembly. Making a set trigger requires small precisely made parts. Look at the set trigger assembly for the K50. It is a modular unit that slips into the pistol.

The Feinwerkbau Model 1 black powder target pistol can be set to low weights. Look at its design for ideas.

The Walther FP eliminated all mechanical parts with its solenoid firing pin. I don't know if that could be sized to fit into a bolt action like the K50. But the rotating breech concept of the Walther is simple.

Posted: Tue Jan 03, 2012 2:54 pm
by j-team
Russ - Sorry, if there's an FP002, it will be mine and of an improved design. To be honest, if I charged up my hours it would cost more than a Morini.

Bob - Yes, it is a little like the Pardini, I used to own a PGP75 about 20 years ago, although I've got the bolt on the L/H side which I think is easier to operate. Mine also has 4 locking lugs, a bit overkill for a .22 but I only wanted to have a 45 degree throw. You are right, you can set the Billinghurst type underhammer pistol trigger quite low, I've built one of those too (see a little pic of it on the left?). I'm quite happy shooting with 100gram trigger and have no plans to change it. Like all triggers, it only feels heavy when I'm shooting badly!

Posted: Tue Jan 03, 2012 5:02 pm
by lxvnrsw
J-team: that's a beautiful pistol! Any chance I could get some close up pictures of your action and maybe a barrel length and diameter? I've got my little martini action all sketched and measured out, but a bolt action might be a bit easier to make in the end. Any other technical specs I could get?

I was planning on using a totally solenoid operated firing pin with a microswitch as the trigger (yeah it's ghetto, but since microswitches come in all different types of trigger weights and depression lengths my plan was to substitute a microswitch/solenoid assembly instead of more complex mechanical set triggers.

I've also already got a small piece of barrel (it's unfortunately 1:8 twist though, which is probably overkill but it was free) and a chamber reamer. Sights will probably be bought prefabricated, but other than that I plan on building everything else myself.

Looks like building a free pistol might just not be that crazy after all!

Posted: Tue Jan 03, 2012 5:22 pm
by j-team
My barrel is 15mm diameter and 250mm long. It sounds like your barrel is .224" centre fire if it's 1 in 8" twist. That won't be the best for accuracy as proper .22 rimfire barrel is .223"and 1 in 16" twist. I chambered a bit short so the bullets engraved the rifleing once seated.

The disadvantage of the bolt action is the length, it means the breech is further forward. If you went with a falling block action you could have a barrel up to 300mm long and still have the same overall length. My first 3 sketches were toggle actions but I ended up with a bolt simply because it was easier. Maybe the next one will be a toggle...

Posted: Tue Jan 03, 2012 5:35 pm
by Bob LeDoux
It may not be difficult to make a pistol that looks like a free pistol, its much more to make it shoot like a free pistol. Other individuals have tried. Look at the A.H. Thompkins and Green designs. The Pardini PGP was built by a shooter, Pardini, who wasn't happy with then current designs.

My Walther and Pardini free pistols came with test targets. Each of them showed a 50 meter ten shot group that could be covered with a USA dime. Those groups only came from a combination of highest quality barrel with proper cartridge chambering and consistent action operation.

I doubt that any of the current manufacturers make a profit on their free pistol products. The market is so small and the required quality is so high. I don't see how they are produced for the price they bear.

Posted: Tue Jan 03, 2012 5:51 pm
by lxvnrsw
Yeah the barrel is surplus from a m16. My goal was to practice chambering and headspacing with it and then put a better barrel on my finished pistol once I have the kinks all worked out of my action.

So it sounds like 300mm overall length is about ideal?

Posted: Tue Jan 03, 2012 6:48 pm
by LukeP
Beautiful pistol!

Posted: Wed Jan 04, 2012 2:59 am
by Praskaton
Maybe I will sound strange, but isn't making firearms in your workshop illegal? In my country, and I know that is the case in most European countries it is illegal. Otherwise, I like the idea, so I'm planning to do something similar. Of course, under the "supervision" authorized gunsmith.

Posted: Wed Jan 04, 2012 5:17 am
by j-team
Praskaton wrote:Maybe I will sound strange, but isn't making firearms in your workshop illegal? In my country, and I know that is the case in most European countries it is illegal. Otherwise, I like the idea, so I'm planning to do something similar. Of course, under the "supervision" authorized gunsmith.
100% legal where I come from so long as you have a firearms license and you are not making them commercially. It must be marked with a serial number, calibre and make though.

Posted: Wed Jan 04, 2012 8:46 am
by RandomShotz
Praskaton wrote: 100% legal where I come from so long as you have a firearms license and you are not making them commercially. It must be marked with a serial number, calibre and make though.
If you mean FFL, which type and what did getting it involve?

These may not just be academic questions. I am also a machinist, and the thought (fantasy?) of making my own single shot action has been hanging around my head for a while. I have one of Frank de Haas's books on single shots, although not one with detailed plans, and I've been thinking along the lines of a falling block action with an electronic release.

I've also been thinking about hitting the lottery, and I figure the odds are fairly similar. But you never know ...


Roger

Posted: Wed Jan 04, 2012 9:45 am
by Bob LeDoux
In the USA federal law states anyone who may legally own a firearm may also build one. No license is required.