.45 Colt/.410 Hammerless over/under pistol....Teaser!

[MachIVshooter]

Been designing this critter in my head, got some ideas down on paper, finally started cutting metal today. I'm not gonna give up too much about what it'll look like just yet, except to say it will basically be a pistol version of a standard single trigger enclosed hammer O/U shotgun. But there'll be no wood and very little steel; only the barrels and internal parts. The receiver, barrel block and front sight/barrel clamp assembly will be 6Al-4V titanium, and the grip frame 7075-T651 aluminum with carbon fiber grip panels. The barrels I purchased here, everything else will be hand made.

So far just got a chunk of Ti cut off, squared up and started cutting the front end of it:



Stay tuned!

 

[Zaydok Allen]

Sounds like a Bond arms Derringer in a lot of ways...... But it sounds like you are going to make it a lot more shootable than a Bond, and yet lighter based on the materials. So I'm guessing the grip will be a much different design, and an internal hammer will make it a lot more stream lined.

Good luck! Looking forward to seeing the final product.

Maybe a modern day Howdah pistol is a better description? Most of the Howdahs had exposed hammers, but not all, and a few of them were over unders.

 

[MachIVshooter]

I'm not sure what the final weight will be, but pretty light for size. Sticking with the full 10.5" of barrel, but they only weigh 6.8 oz each. I'm thinking final weight will be in the 2-2.5 lb range. A standard 12 ga O/U receiver with internals weighs around 2 lbs, but Ti is 42% lighter than steel, and my dimensions are 25% smaller. The grip frame won't weigh much, either.

 

[Zaydok Allen]

Sticking with the full 10.5" of barrel

Really! Oh, so this is more like a handy survival shotgun/45 cal slug thrower than anything? That's interesting. Hmmmm. You could go longer and put some sort of protective cap on the endto protect the muzzle and turn it into a gentlemen's cane, or woods walking stick. This is a neat concept.

 

[horsemen61]

Very cool I love following your threads op have fun

 

[Darkbob]

Looking forward to watching the progress. Your fab threads are fantastic!

 

[bannockburn]

Eagerly awaiting seeing the work in progress and the final design!

 

[RustHunter87]

This looks like it's gonna be awesome!

 

[GRIZ22]

Pedersoli is making a side by side 45 Colt pistol looking like an Ithaca Auto Burglar. Read they are going to offer it in a 45/410.

 

[MachIVshooter]

Moving along, but it's slow going with Ti. Because the pistol will have no fore end like a typical O/U shotgun to keep the barrels from flopping off, and because I've no way to cut dowl recesses on the inside of the receiver ears anyway, we are going to use screws that I will machine to fit the 7/16 holes, threaded into the barrel block, probably 5/16-40. Not yet decided if those will be steel or Ti.

 

[horsemen61]

Cool!!!!!

 

[Dr.Rob]

You sir, are a nut and we love seeing your projects.

 

[DaisyCutter]

*WOW* This is cool.

 

[MachIVshooter]

A little more progress. Unfortunately, I got impatient and decided to finish boring the cocking rod hole with a standard twist drill instead of waiting for the extra long 3/16 carbide end mill, and it flexed a little. Gonna have to go back at it with the carbide cutter to straighten it out. Won't affect function, just annoys me that the back end of the hole will be slightly oblong.



Smoked one of my HSS keyslot cutters making the hammer and sear channels, but got through it. Still some finish work to do on the hammers, but they're 90%. Cut from D2 tool steel

 

[MachIVshooter]

Moving along

 

[horsemen61]

Awesome

 

[MachIVshooter]

Had a little time this afternoon, so got the grip frame roughed out of 1" 7075-T651 today



And the parts I have thus far overlaid for a general idea of what the finished product will be:

 

[Zaydok Allen]

Coming together nicely.

 

[MachIVshooter]

Moving along

 

[Dave Markowitz]

Neat!

 

[MachIVshooter]

More internal parts made and fitted. Firing pins, breech lock and safety still need to be done, though

 

[sgt127]

Since the barrels are rifled, you are simply making a .45 cal pistol, therefore, no license, AOW tax. Nothing. Correct?

That is very cool. And, you've got some skills. Very nice.

 

[MachIVshooter]

Since the barrels are rifled, you are simply making a .45 cal pistol, therefore, no license, AOW tax. Nothing. Correct?

Correct. A title I handgun, just like the Judge, Governor, Thunder Five and .45/.410 Derringers.

 

[MachIVshooter]

Had a pretty quiet day around the shop yesterday, so decided to attack the breech lock. I had originally decided on a top lock for simplicity, but in retrospect, a conventional bottom lock probably would have been easier. It took almost 4 hours to make the locking block/rear sight assembly, another 3 to machine the recesses in the barrel block and channel in the receiver, and then about another 2 hours of hand fitting to get everything to move properly & smoothly, including the use of valve grinding compound and polish for final fitting.

This time it actually occurred to me to take a few shots of the machining processes as well:

Indicating the block of D2 on the roatary table



Cutting the lugs



Many steps later, the finished piece

Cutting the channel in the receiver. This part was horrible. Would have been bad enough in steel, but trying to cut a .750" deep .125 wide channel in 6/4 Ti with almost 3" of end mill hanging out of an extension collet is nerve racking. I started out with a 2 fl carbide ball mill that has a 1/4" shank, but it's max DOC was .400", so the remaining .350" had to be done with my only other style of long reach 1/8, which are ball end 4 fl carbides with straight 1/8 shanks. In the end, there was so much deflection that I had to finish with a Dremel.



Lugs retracted (that slightly marred up section in the channel is where the #10-32 grub screw threads in to retain the lock)



And extended



It is a spring loaded latch, and it does function automatically on close; they needn't be manually held back.






And closed

 

[Zaydok Allen]

This is a really fun thread to follow. Are you a machinist by trade and this is your in home just for fun setup? Or is this strictly a hobby for you?