Gunsmithing What a S&W 2 piece barrel looks like - removed

[cal50]

If you are curious what a S&W 500 with the 8 3/8" factory comp barrel looks like removed and the various parts look inside......


I will post the project pics in the gunsmith section once complete.
The end goal is a 6" barrel S&W 500 with external barrel but / no comp.


More pics at the end of the video~

 

[pawprint2]

I'd love to see the "finished" piece. More Photos please!

 

[cal50]

Well the before pics-

 

[cal50]

Time to start machining parts..... Sorry for the crappy cell phone pics.

I put the saw cut barrel shroud in the lathe, set it up with a 4-jaw chuck to face the saw cut end square and parallel to the opposite end of the shroud ( the end that contacts the frame ).

Face off in lathe~





This was a simple and not a hard thing to do. I still need to mill a .250 slot and tap a hole for the new front sight base but that's another day. I put the saw cut barrel in the lathe and faced off the saw cut end. I then cut an 11 degree crown and polished it up so its burr free and nice looking.
Now that the barrel is faced and crowned it needs threads for its new barrel nut. S&W uses a 36 pitch thread in the frame and barrel so I am using the same 36 pitch for the new muzzle nut & OD barrel threads. This is a simple single point thread cutting job. I could not find my favorite flip tip carbide tool so I used my other good threading tool. I cut the threads until I have a sharp "V" thread.


Cutting threads~




Once the barrel threads were finished I looked around for a piece of O-1 tool steel to make a new barrel nut from. I will heat treat the nut and finish it in black Cerrakote or similar when I wrap it up.The only material I had was 1 1/4 diameter so I turned it down to .875 ( the width of the barrel shroud ), drilled and bored the ID to the proper diameter for threading.

Now its single point threading the ID threads~




Once I got close to size I used the barrel I just threaded as a gauge to fit the nut to. This amount to getting close in size then making .001 diameter passes and test fitting the barrel and nut together. On fin pitch threads .001 a pass does not sound like a lot but it really is.

Test fit~




Once I was satisfied with the proper fit the nut was removes from the lathe chuck. If it did not fit its a pain in rear to try to pick up the thread lead and forget about finding a tap that size...

I wiped down the barrel shroud, screwed the barrel into the frame, slid the shroud on and.....


Nice threads and crown~




Side view~





Now I screwed on the barrel nut and calling it a night. The nut is WAY long and I will use a groove tool to cut it to the exposed barrel length and have enough left over for a extra. I will need to face the nut to length then mill slots to engage a tool to tighten it ( I have not made it yet ).




I might add a radius to the front under lug on the barrel, undecided now.

 

[Travis S]

That's pretty cool. There was a guy that had a run of the 500's without a comp. My wrists say no thanks though.

 

[cal50]

Some progress on my project-

My cut down shroud now has no front sight or base. I am using a quick change gunsmith base that requires a .250 slot milled into the shroud and a 6-48 hole drilled and tapped to retain it. First I needed to do a little math and see how high my factory / stock sight was. With the sight blade installed it measures 1.9405 so I want to duplicate this height with my new sight and base. A quick measurement of the base & sight sitting on top of the shroud and subtracting the two gave me a difference of .084 milling depth into the shroud to duplicate the same sight height.

The cut off section measurement- 1.9405


The shroud with new base installed- 1.9410


The difference is .0005 thousandths and I can live with that.

Slot milled / hole tapped-



Tapping the hole straight-




Looks good-

 

[cal50]

After a detour for family related health issues some progress....

I milled notches in my soon to be barrel nut that will mate with the tool I have not made yet to tighten it down. This a A2 tool steel and I have not heat treated it yet.

Milling .093 slots-



After its cut and faced off to length to match flush with the exposed barrel threads-




I added a radius on the bottom of the shroud for cosmetic appeal. It has not been buffed up yet to a mirror shine.








The business end with nut hand tight-




An idea how the new profile will look. Think of it as my pistol having a massive nose job....
The balance is MUCH improved.

 

[matthias]

Looks good. I like the front sight ramp and how you set it into the shroud. I may have to do something like that on my itty bitty 64 smith. Thanks for the update

 

[sakobob]

looks like a nice proportionate pistol now , one question ,why not put the barrel nut in the shroud so the barrel ,shroud and nut are all flush
with the muzzle? .

 

[cal50]

looks like a nice proportionate pistol now , one question ,why not put the barrel nut in the shroud so the barrel ,shroud and nut are all flush
with the muzzle? .

The shroud is not thick enough to bury a nut and have adequate nut thickness / the nut would have to be REALLY thin.
To make that idea work I would need to turn some off the barrel diameter and I did not want to go there.

Believe me , I would like a Dan Wesson similar system......

 

[rikkn]

Awesome machine work.

 

[sakobob]

gotcha. . . that would be tough and risky being that thin.

 

[cal50]

Wrapping up my project....

I heat treated my barrel nut and spanner tool. I made them from A2 air hardening steel. I flame hardened them and normalized them. The black finish on them now is just quench oil that once cooled I dunked them in quench oil and put them back in the oven and let it burn off. It temporary until I have other parts to finish. The spanner tool I inserted a donor craftsman socket for the 3/8 drive so I can attach it to a hand breaker bar or torque wrench.










My barrel had a burr on the area around the forcing cone / barrel face. I removed it, lapped the barrel face flat and polished it. There is no way you can accurately measure or set the barrel gap with a burr on this surface. Maybe this is why my gun measured .010 which was on the high side. I will be setting it to .005 which is a nice middle of the road size.
I applied some anti-seize to the barrel threads and inserted into the frame.








New gap set-




What is left to do is tighten the barrel nut. I torqued it firmly and will need to test fire. It should be similar to my old Dan Wesson but I will keep an eye on it.






I dropped my gun on the scales to see how much weight I lopped off. The beam balance said it weighs 1781.5 grams or 62.8 ounces. I did not weigh the stock gun but S&W lists it at 71.9 ounces so this would be a weight loss of 9.1 ounces. I can REALLY fell the difference an it balances SOoooo much better now.

 

[cal50]

Now the finial pics-

It was a fun to do project and I now have a pair of gun that the same in title and caliber feel completely different.