Older S&W Pinned Barrel question

[Oyeboten]

If wishing to change Barrels on an older S&W Revolver having a pinned Barrel...does the Pin Location of the new Barrel typically have to be finessed, for the old Pin and Frame hole to align with the pin slot of the New Barrel?


I will find out, of course, but, just wondering if those of you who have been there would care to share any reminiscences?


And or how is this usually dealt with?

 

[dfariswheel]

Totally depends on where the barrel screws in.

You can't just screw in the barrel, turn it so the front sight is upright, then stick the pin in.
Even these older pinned barrels have to be torqued in place, just not as tightly as the non-pinned.

Basically, here's how to fit a revolver barrel, including a pinned version. This assumes you have the frame wrench with S&W inserts for that size frame, the correct barrel vise inserts, and the special cutting set for the barrel/cylinder gap and forcing cone, along with the plug gage for the cone:

After removing the old barrel with the frame wrench. (Use the old hammer handle trick, and you can probably kiss your frame good by).

Screw in the barrel until its snug than judge how much metal has to be removed from the shoulder to allow the barrel to torque up with the front sight at 12:00 o'clock.

Remove that amount with a lathe.

Screw the barrel back on and torque in place with the frame wrench and barrel vise.
The old pinned barrel does need to be fairly tight to prevent vibration from ruining accuracy.

Carefully using the correct drill, drill the barrel groove.
Remember, the idea is to cut a new groove in the barrel, NOT enlarge the hole in the frame, or drill off and ruin the frame.

Install the pin.

Gage the barrel/cylinder gap. With a new barrel the cylinder should not close because the barrel shank will be too long. If necessary, you may need to use the lathe to set the barrel back one thread.

Insert the tee handle from the cutter set down the bore, and use the flat face cutter to trim the rear of the barrel to set barrel/cylinder gap.
Make sure to use even pulling force on the tee handle to prevent scalloping the rear of the barrel.
Ideally, the barrel/cylinder gap should be 0.005". Under 0.003" or so and you usually get cylinder binding on the barrel.

With the gap set, change to the forcing cone cutter head and re-cut the forcing cone. S&W uses a 9 1/2 degree cone, but you can go to an 11 degree for lead bullets if you want.
Stop OFTEN and use the drop in forcing cone plug gage to gage the cone.
The critical area is the MOUTH of the forcing cone, not the angle.
Too large a diameter and accuracy suffers.
Too small and the gun will spit lead and be inaccurate.
The difference between too large and too small is tiny and you can't eyeball it, you have to use the gage.

After cutting to the proper spec, change to the brass lapping head and use valve grinding compound to lap the forcing cone smooth.

Clean up and test for accuracy off the sand bags.

The bottom line on all this is that barrel changes are considerably more than just screwing on a different barrel like its just a piece of threaded pipe.
Simply screwing on the barrel until the front sight is upright and the pin hole lines up ain't gonna do it.
Re-barreling is one of the most involved pistolsmith Jobs there is other than fitting a new cylinder.
It takes some expensive tools, and the knowledge of how to use them.
The barrel has to be torqued snug, properly aligned, the barrel/cylinder gap has to be right, and the forcing cone MUST be properly done.

 

[Oyeboten]

Hi dfariswheel,



Thank you...


Yeahhhhh...thought so.


Hmmmm...


Only 'Lead' for me...Bullet wise...


I had read up on the procedure some while back, but, could not recall any clear mention on the Pin alignment issue.


Anyway...I have a Model 10 I would like to re-Barrel, and, I have a right kind Barrel for it.


Understood as for not stressing the Frame with torgue applied to it's wider farther parts.


Just debating on whether to try finding a caring won't-screw-things-up Smith, or, giving it a try myself.


Seems like every time I ever jobbed anything out, the guy really screwed up, got the clear written agreement goofed up and did wrong things, or worse, no matter how well recommended he was or his supposed track record, so I am scared to ever risk anything of value to anyone else's hand again.



I have a Metal Lathe, and, the Jigs and Holders and so on I can make I'd expect.


The forcing Cone reamers, I could make or buy.


Do I take it then that you have done this procedure a time or two?

 

[dfariswheel]

Do I take it then that you have done this procedure a time or two?

Mostly on Colt double actions, but... a LOT of Colt double actions over 30 years.

Here's some help.
First buy a copy of the Jerry Kuhnhausen shop manual.
This is a real gunsmiths manual written to train new pistolsmiths.
It VERY fully covers fitting new barrels the factory way:

http://www.brownells.com/.aspx/pid=25717/Product/THE_S_W_REVOLVER___A_SHOP_MANUAL

You can buy all the tools from Brownell's, including the frame wrench, forcing cone tools and gage, and even a bench top barrel shoulder cutter so you don't have to have a lathe:

http://www.brownells.com/.aspx/pid=854/Product/BARREL_SET_BACK_FIXTURE

The forcing cone cutter tools and gage take up an entire page in the catalog.

Frame wrench and inserts. Make barrel blocks from hardwood and epoxy.
http://www.brownells.com/.aspx/pid=25104/Product/REVOLVER_ACTION_WRENCH

 

[Oyeboten]

Hi dfariswheel,


Thanks so much for your replies on this....especially regarding their high order of germain detail.


I have actually two ( 2 ) S&W, K-Frame, re-Barrel projects I would like to do.

One, a Model 10-5...the other, a circa 1915 or so low low miliage, slight incidental pitting exterior, 'M&P' Model with a conspicuous Barrel 'Bulge' right under the front Sight ( not by me! Was that way when I bought it, and was why I bought it - knowing I would like to learn to re-barrel some day )...

Or, I could heat and craefully 'dolly' the 'bulge' back down, re-bore the effected area, and, re-cut the Rifling, I s'pose...yes?

Regardless...

This would be a really good opportunity I think for me to learn, learn critically more, understand more, appreciate more, and, gain detailed experience by careful, methodical, patient, planning, sequence, and doing.


Jobbing things out, I would not learn much...


Well...I'll keep brooding and rehersing in my thoughts till the time comes.

I do have the Kuhnhausen Book, and, a few others, also, which I put in Storage during some bad leaky Roof issues last November...

Next few months, Work-Work things fill my days and nights 7 days-a-week but for occasional stolen minutes on THR...


My Metal Lathe is a very low milleage 'South Bend', 6 inch Throw I think, made 1934, on the Factory Accessory Stand...all the Back Gearing, various Three and Four Jaw Chucks, various 'Jacob's Chucks', and I forget what else.

Good Drill Presses I have and use routinely anyway.

I bought the Lathe several years ago, and have been so swamped since, I have not yet set it all up to begin my self-instruction experiments on it.

I am used to a Wood Lathe, which I know has it's crucial differences, as my Livlihood involves among other things, many Hundreds of precise Wood Turnings a Month.


So I understand fairly well the principles and overall operations of a Metal Lathe, Feeds, Cutting Tool geometry and respective Cuting Tool Materials for differing Materials and RPMs, Coolant/Lube, even if I am not yet practiced on it.

I had a little thing I needed made, went to a Machine Shop I have known for over twenty years, trusted they would be reasonable, and, they soaked me $115.00 for the little thing, and I supplied the Material even.

Came home, feeling pouty, took some same material, chucked it in the Wood Lathe, in a No. 2 Morse Jacob's Chuck, made sure it was Centered alright n that end, far end on a Live Spindle/Center, and, by Hand, I made a closer-tolerance same stepped diameter part in twenty minutes.

Mine miked out to + or - .003...theirs, + or - .007.

And I used hand held self-made Tooling on a normal Wood Lathe Rest, they had sophisticated digital Lathes with positive Tool-Holders and all the rest of course.

If they'd have sought out my Craft, I would never have charged them over $200.00 an Hour for 'simple' Manual Art's process....but oh well, the sorrows of being on THIS side-of-the-counter..!


Lol...


Oye...


Anyway...


Feeling definitely positive about trying this...

 

[navyretired 1]

The only thing I would add is don't drill pin hole with barrel installed unless the new barrel doesn't have a groove for pin. Install barrel and do all fitting first, the run a drill bit of correct size into hole from both sides just to mark barrel. Then take barrel off and file groove, the pin is an anti rotation device not a machine fit pin and drilling while installed might work if done very slowley but the surface cutting speed would be way off and the drill WILL try to follow any other groove till hole is badley egg shaped.

 

[Oyeboten]

Hi navyretired 1,


Thank you...makes perfect sense.


Glad you mentioned this.

Will do.

Candidate Barrels are old used ones in good condition, but show old perpendicular half-round channels ( or even somewhat wallowed versions of them, ) where the Pin had once crossed.


So we shall see...

 

[Old Fuff]

K-frame barrels have a .540 x 36 RH thread. Brownells sell a tap & die set which is handy if you have to clean up the threads in either the frame or barrel. Be very careful to be sure that the tap or die is in straight because the idea is not to start cutting a new thread! While it is not always necessary, expect that you will have to remove a bit of metal from the barrel's shoulder to get the sight to come up at 12:00, and if the barrel is set back yoy may have to remove some from the back end of the barrel to adjust the barrel/cylinder gap, and also from the end of the ejector rod and cylinder center pin. You can make life easier later if you polish the barrel throat before you install the barrel. I don't think you will have problems with the barrel pin unless the new barrel has to be set back considerably, but do run a drill through the frame's hole by hand just to check, and finish setting the pin with a cup-pointed punch so you don't mar the topstrap.

www.brownells.com

 

[Oyeboten]

Hi Old Fuff,


Thank you for the mentions.


Makes sense...


Indeed, Cup-End Punches ( particularly the one for the Pin in question ) are top o' the List of things to get.

The two Candidate Revolvers, far as I know, have never been dis-assembled Barrel wise...and, the Threads of the Barrels I have in mind to use on them appear crisp and un-damaged.

As I reherse this in my imagination, the new Barrel either screws in snug with the Sight at a perfect "12:00" O'clock...or, at 11:52, requiring then the Boss or Shoulder of the Barrel to be reduced some tiny bit, or, it snugs-up at ohhhhh, 12:10, or 2:15 or something horrible like that...


Lol...

I guess a Washer might work ( ducking as I laugh...) but, people might make fun of me.


Forcing Cone interior wise - I have no interest in shooting anything but Lead Bullets, so, those Reamers which make the right taper for that are on my List also.


I think the really early K-Frames had a different Barrel Thread...but, my older one is not old enough for that detail to be present.

 

[madcratebuilder]

The only thing I would add is don't drill pin hole with barrel installed unless the new barrel doesn't have a groove for pin. Install barrel and do all fitting first, the run a drill bit of correct size into hole from both sides just to mark barrel. Then take barrel off and file groove, the pin is an anti rotation device not a machine fit pin and drilling while installed might work if done very slowley but the surface cutting speed would be way off and the drill WILL try to follow any other groove till hole is badley egg shaped.

+1

I have done three barrel changes on k frames and found the new barrel pin groove the most tedious part of the entire project, followed by setting the barrel shoulder back for proper sight alignment.

Having the correct tooling is half the battle. You can make a barrel vise and frame wrench with little trouble. The special tools from Brownells cost dearly but if you have a C&R you can setup a dealer account and get about 20-25% discount.

 

[Oyeboten]

Hi madcratebuilder,


Makes sense...


I can see in merely holding some of the Candidate Barrels to the present complete Revolvers, that the 'new' Barrel in some cases, at the Forcing Cone to Cylinder area, will have too large a gap there, and will need to be trimmed at the Boss which seats against the front of the Frame.


The dimple-nose Punch one would use, to drive out the Barrel Pin, is this a well known size then?

If appealing to say 'Brownells', would one order the appropriate Punch by a Standard size designation or Number?

Barrel Pin is plain, not Tapered?...and, may be driven out from either side?

 

[Old Fuff]

The pin is straight.

The cup-point punches come in a set, which is S&W specific. When I get a minute I'll look up the stock number.

Brownells have a section in their catalog covering Smith & Wesson revolvers. In it they offer a number of special tools, jigs and fixtures. Some of them are so expensive that only professional gunsmiths would be interested. Others, such as product specific pin punches and screwdrivers are somthing anyone who so much as pops a sideplate should have.

And the first thing they should buy (but often don't) is a shop manual.

 

[Oyeboten]

Thanks Old Fuff,


I do indeed have a Shop Manual, possibly two different ones, and, several other quite good Books, got over the last year or so, which I need to bring home from Storage.


I will also see if I can find my 'Brownells' Catalogue, which I know I had sent off for months ago.


I will send off then for the propretary Punch Set.


I am good on Gunsmith trype Screw Drivers...having sent off for a set which uses 'Apex' Bits, and I have many extra Bits ( or extant conventional Screw Drivers ) which I can re-grind as needed if I am not satisfied with the choices already represented in the set.

 

[Old Fuff]

Brownells S&W cup-point / 6 pc. set: #080 620 306

Last retail price I have is $45.00 Don't know if they sell individual punches or not, but you could ask. The idea is to start the pin with the cup-pointed punch. After you get about 1/8" into the hole you can switch to a flat-pointed punch which is far less expensive. Starting a round-headed pin with a flat punch is asking for a dinged-up gun. Don't do it!

 

[Oyeboten]

Thanks Old Fuff


I copy..!


Would one warm the Revolver Frame? Immersion in Boiling Water, say? As a means of allowing the differential expansion to permit an easier passage of the Pin, as it is driven out?

Or, how 'tight' do these Pins seem to have been in various of your-plural memories?



Ditto, for un-screwing the Barrel?


How 'tight' the Barrell may be, might be more varied, given the nature of how they are fit to begin with...I'd guess...yes?